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+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
+M68000 Hi-Performance Microprocessor Division
+M68060 Software Package
+Production Release P1.00 -- October 10, 1994
+
+M68060 Software Package Copyright 1993, 1994 Motorola Inc. All rights reserved.
+
+THE SOFTWARE is provided on an "AS IS" basis and without warranty.
+To the maximum extent permitted by applicable law,
+MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
+INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
+and any warranty against infringement with regard to the SOFTWARE
+(INCLUDING ANY MODIFIED VERSIONS THEREOF) and any accompanying written materials.
+
+To the maximum extent permitted by applicable law,
+IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
+(INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS,
+BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR OTHER PECUNIARY LOSS)
+ARISING OF THE USE OR INABILITY TO USE THE SOFTWARE.
+Motorola assumes no responsibility for the maintenance and support of the SOFTWARE.
+
+You are hereby granted a copyright license to use, modify, and distribute the SOFTWARE
+so long as this entire notice is retained without alteration in any modified and/or
+redistributed versions, and that such modified versions are clearly identified as such.
+No licenses are granted by implication, estoppel or otherwise under any patents
+or trademarks of Motorola, Inc.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# ireal.s:
+# This file is appended to the top of the 060ISP package
+# and contains the entry points into the package. The user, in
+# effect, branches to one of the branch table entries located
+# after _060ISP_TABLE.
+# Also, subroutine stubs exist in this file (_isp_done for
+# example) that are referenced by the ISP package itself in order
+# to call a given routine. The stub routine actually performs the
+# callout. The ISP code does a "bsr" to the stub routine. This
+# extra layer of hierarchy adds a slight performance penalty but
+# it makes the ISP code easier to read and more mainatinable.
+#
+
+set _off_chk, 0x00
+set _off_divbyzero, 0x04
+set _off_trace, 0x08
+set _off_access, 0x0c
+set _off_done, 0x10
+
+set _off_cas, 0x14
+set _off_cas2, 0x18
+set _off_lock, 0x1c
+set _off_unlock, 0x20
+
+set _off_imr, 0x40
+set _off_dmr, 0x44
+set _off_dmw, 0x48
+set _off_irw, 0x4c
+set _off_irl, 0x50
+set _off_drb, 0x54
+set _off_drw, 0x58
+set _off_drl, 0x5c
+set _off_dwb, 0x60
+set _off_dww, 0x64
+set _off_dwl, 0x68
+
+_060ISP_TABLE:
+
+# Here's the table of ENTRY POINTS for those linking the package.
+ bra.l _isp_unimp
+ short 0x0000
+
+ bra.l _isp_cas
+ short 0x0000
+
+ bra.l _isp_cas2
+ short 0x0000
+
+ bra.l _isp_cas_finish
+ short 0x0000
+
+ bra.l _isp_cas2_finish
+ short 0x0000
+
+ bra.l _isp_cas_inrange
+ short 0x0000
+
+ bra.l _isp_cas_terminate
+ short 0x0000
+
+ bra.l _isp_cas_restart
+ short 0x0000
+
+ space 64
+
+#############################################################
+
+ global _real_chk
+_real_chk:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_chk,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _real_divbyzero
+_real_divbyzero:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_divbyzero,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _real_trace
+_real_trace:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_trace,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _real_access
+_real_access:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_access,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _isp_done
+_isp_done:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_done,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+#######################################
+
+ global _real_cas
+_real_cas:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_cas,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _real_cas2
+_real_cas2:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_cas2,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _real_lock_page
+_real_lock_page:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_lock,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _real_unlock_page
+_real_unlock_page:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_unlock,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+#######################################
+
+ global _imem_read
+_imem_read:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_imr,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _dmem_read
+_dmem_read:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_dmr,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _dmem_write
+_dmem_write:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_dmw,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _imem_read_word
+_imem_read_word:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_irw,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _imem_read_long
+_imem_read_long:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_irl,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _dmem_read_byte
+_dmem_read_byte:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_drb,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _dmem_read_word
+_dmem_read_word:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_drw,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _dmem_read_long
+_dmem_read_long:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_drl,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _dmem_write_byte
+_dmem_write_byte:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_dwb,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _dmem_write_word
+_dmem_write_word:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_dww,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+ global _dmem_write_long
+_dmem_write_long:
+ mov.l %d0,-(%sp)
+ mov.l (_060ISP_TABLE-0x80+_off_dwl,%pc),%d0
+ pea.l (_060ISP_TABLE-0x80,%pc,%d0)
+ mov.l 0x4(%sp),%d0
+ rtd &0x4
+
+#
+# This file contains a set of define statements for constants
+# in oreder to promote readability within the core code itself.
+#
+
+set LOCAL_SIZE, 96 # stack frame size(bytes)
+set LV, -LOCAL_SIZE # stack offset
+
+set EXC_ISR, 0x4 # stack status register
+set EXC_IPC, 0x6 # stack pc
+set EXC_IVOFF, 0xa # stacked vector offset
+
+set EXC_AREGS, LV+64 # offset of all address regs
+set EXC_DREGS, LV+32 # offset of all data regs
+
+set EXC_A7, EXC_AREGS+(7*4) # offset of a7
+set EXC_A6, EXC_AREGS+(6*4) # offset of a6
+set EXC_A5, EXC_AREGS+(5*4) # offset of a5
+set EXC_A4, EXC_AREGS+(4*4) # offset of a4
+set EXC_A3, EXC_AREGS+(3*4) # offset of a3
+set EXC_A2, EXC_AREGS+(2*4) # offset of a2
+set EXC_A1, EXC_AREGS+(1*4) # offset of a1
+set EXC_A0, EXC_AREGS+(0*4) # offset of a0
+set EXC_D7, EXC_DREGS+(7*4) # offset of d7
+set EXC_D6, EXC_DREGS+(6*4) # offset of d6
+set EXC_D5, EXC_DREGS+(5*4) # offset of d5
+set EXC_D4, EXC_DREGS+(4*4) # offset of d4
+set EXC_D3, EXC_DREGS+(3*4) # offset of d3
+set EXC_D2, EXC_DREGS+(2*4) # offset of d2
+set EXC_D1, EXC_DREGS+(1*4) # offset of d1
+set EXC_D0, EXC_DREGS+(0*4) # offset of d0
+
+set EXC_TEMP, LV+16 # offset of temp stack space
+
+set EXC_SAVVAL, LV+12 # offset of old areg value
+set EXC_SAVREG, LV+11 # offset of old areg index
+
+set SPCOND_FLG, LV+10 # offset of spc condition flg
+
+set EXC_CC, LV+8 # offset of cc register
+set EXC_EXTWPTR, LV+4 # offset of current PC
+set EXC_EXTWORD, LV+2 # offset of current ext opword
+set EXC_OPWORD, LV+0 # offset of current opword
+
+###########################
+# SPecial CONDition FLaGs #
+###########################
+set mia7_flg, 0x04 # (a7)+ flag
+set mda7_flg, 0x08 # -(a7) flag
+set ichk_flg, 0x10 # chk exception flag
+set idbyz_flg, 0x20 # divbyzero flag
+set restore_flg, 0x40 # restore -(an)+ flag
+set immed_flg, 0x80 # immediate data flag
+
+set mia7_bit, 0x2 # (a7)+ bit
+set mda7_bit, 0x3 # -(a7) bit
+set ichk_bit, 0x4 # chk exception bit
+set idbyz_bit, 0x5 # divbyzero bit
+set restore_bit, 0x6 # restore -(a7)+ bit
+set immed_bit, 0x7 # immediate data bit
+
+#########
+# Misc. #
+#########
+set BYTE, 1 # len(byte) == 1 byte
+set WORD, 2 # len(word) == 2 bytes
+set LONG, 4 # len(longword) == 4 bytes
+
+#########################################################################
+# XDEF **************************************************************** #
+# _isp_unimp(): 060ISP entry point for Unimplemented Instruction #
+# #
+# This handler should be the first code executed upon taking the #
+# "Unimplemented Integer Instruction" exception in an operating #
+# system. #
+# #
+# XREF **************************************************************** #
+# _imem_read_{word,long}() - read instruction word/longword #
+# _mul64() - emulate 64-bit multiply #
+# _div64() - emulate 64-bit divide #
+# _moveperipheral() - emulate "movep" #
+# _compandset() - emulate misaligned "cas" #
+# _compandset2() - emulate "cas2" #
+# _chk2_cmp2() - emulate "cmp2" and "chk2" #
+# _isp_done() - "callout" for normal final exit #
+# _real_trace() - "callout" for Trace exception #
+# _real_chk() - "callout" for Chk exception #
+# _real_divbyzero() - "callout" for DZ exception #
+# _real_access() - "callout" for access error exception #
+# #
+# INPUT *************************************************************** #
+# - The system stack contains the Unimp Int Instr stack frame #
+# #
+# OUTPUT ************************************************************** #
+# If Trace exception: #
+# - The system stack changed to contain Trace exc stack frame #
+# If Chk exception: #
+# - The system stack changed to contain Chk exc stack frame #
+# If DZ exception: #
+# - The system stack changed to contain DZ exc stack frame #
+# If access error exception: #
+# - The system stack changed to contain access err exc stk frame #
+# Else: #
+# - Results saved as appropriate #
+# #
+# ALGORITHM *********************************************************** #
+# This handler fetches the first instruction longword from #
+# memory and decodes it to determine which of the unimplemented #
+# integer instructions caused this exception. This handler then calls #
+# one of _mul64(), _div64(), _moveperipheral(), _compandset(), #
+# _compandset2(), or _chk2_cmp2() as appropriate. #
+# Some of these instructions, by their nature, may produce other #
+# types of exceptions. "div" can produce a divide-by-zero exception, #
+# and "chk2" can cause a "Chk" exception. In both cases, the current #
+# exception stack frame must be converted to an exception stack frame #
+# of the correct exception type and an exit must be made through #
+# _real_divbyzero() or _real_chk() as appropriate. In addition, all #
+# instructions may be executing while Trace is enabled. If so, then #
+# a Trace exception stack frame must be created and an exit made #
+# through _real_trace(). #
+# Meanwhile, if any read or write to memory using the #
+# _mem_{read,write}() "callout"s returns a failing value, then an #
+# access error frame must be created and an exit made through #
+# _real_access(). #
+# If none of these occur, then a normal exit is made through #
+# _isp_done(). #
+# #
+# This handler, upon entry, saves almost all user-visible #
+# address and data registers to the stack. Although this may seem to #
+# cause excess memory traffic, it was found that due to having to #
+# access these register files for things like data retrieval and <ea> #
+# calculations, it was more efficient to have them on the stack where #
+# they could be accessed by indexing rather than to make subroutine #
+# calls to retrieve a register of a particular index. #
+# #
+#########################################################################
+
+ global _isp_unimp
+_isp_unimp:
+ link.w %a6,&-LOCAL_SIZE # create room for stack frame
+
+ movm.l &0x3fff,EXC_DREGS(%a6) # store d0-d7/a0-a5
+ mov.l (%a6),EXC_A6(%a6) # store a6
+
+ btst &0x5,EXC_ISR(%a6) # from s or u mode?
+ bne.b uieh_s # supervisor mode
+uieh_u:
+ mov.l %usp,%a0 # fetch user stack pointer
+ mov.l %a0,EXC_A7(%a6) # store a7
+ bra.b uieh_cont
+uieh_s:
+ lea 0xc(%a6),%a0
+ mov.l %a0,EXC_A7(%a6) # store corrected sp
+
+###############################################################################
+
+uieh_cont:
+ clr.b SPCOND_FLG(%a6) # clear "special case" flag
+
+ mov.w EXC_ISR(%a6),EXC_CC(%a6) # store cc copy on stack
+ mov.l EXC_IPC(%a6),EXC_EXTWPTR(%a6) # store extwptr on stack
+
+#
+# fetch the opword and first extension word pointed to by the stacked pc
+# and store them to the stack for now
+#
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_long # fetch opword & extword
+ mov.l %d0,EXC_OPWORD(%a6) # store extword on stack
+
+
+#########################################################################
+# muls.l 0100 1100 00 |<ea>| 0*** 1100 0000 0*** #
+# mulu.l 0100 1100 00 |<ea>| 0*** 0100 0000 0*** #
+# #
+# divs.l 0100 1100 01 |<ea>| 0*** 1100 0000 0*** #
+# divu.l 0100 1100 01 |<ea>| 0*** 0100 0000 0*** #
+# #
+# movep.w m2r 0000 ***1 00 001*** | <displacement> | #
+# movep.l m2r 0000 ***1 01 001*** | <displacement> | #
+# movep.w r2m 0000 ***1 10 001*** | <displacement> | #
+# movep.l r2m 0000 ***1 11 001*** | <displacement> | #
+# #
+# cas.w 0000 1100 11 |<ea>| 0000 000* **00 0*** #
+# cas.l 0000 1110 11 |<ea>| 0000 000* **00 0*** #
+# #
+# cas2.w 0000 1100 11 111100 **** 000* **00 0*** #
+# **** 000* **00 0*** #
+# cas2.l 0000 1110 11 111100 **** 000* **00 0*** #
+# **** 000* **00 0*** #
+# #
+# chk2.b 0000 0000 11 |<ea>| **** 1000 0000 0000 #
+# chk2.w 0000 0010 11 |<ea>| **** 1000 0000 0000 #
+# chk2.l 0000 0100 11 |<ea>| **** 1000 0000 0000 #
+# #
+# cmp2.b 0000 0000 11 |<ea>| **** 0000 0000 0000 #
+# cmp2.w 0000 0010 11 |<ea>| **** 0000 0000 0000 #
+# cmp2.l 0000 0100 11 |<ea>| **** 0000 0000 0000 #
+#########################################################################
+
+#
+# using bit 14 of the operation word, separate into 2 groups:
+# (group1) mul64, div64
+# (group2) movep, chk2, cmp2, cas2, cas
+#
+ btst &0x1e,%d0 # group1 or group2
+ beq.b uieh_group2 # go handle group2
+
+#
+# now, w/ group1, make mul64's decode the fastest since it will
+# most likely be used the most.
+#
+uieh_group1:
+ btst &0x16,%d0 # test for div64
+ bne.b uieh_div64 # go handle div64
+
+uieh_mul64:
+# mul64() may use ()+ addressing and may, therefore, alter a7
+
+ bsr.l _mul64 # _mul64()
+
+ btst &0x5,EXC_ISR(%a6) # supervisor mode?
+ beq.w uieh_done
+ btst &mia7_bit,SPCOND_FLG(%a6) # was a7 changed?
+ beq.w uieh_done # no
+ btst &0x7,EXC_ISR(%a6) # is trace enabled?
+ bne.w uieh_trace_a7 # yes
+ bra.w uieh_a7 # no
+
+uieh_div64:
+# div64() may use ()+ addressing and may, therefore, alter a7.
+# div64() may take a divide by zero exception.
+
+ bsr.l _div64 # _div64()
+
+# here, we sort out all of the special cases that may have happened.
+ btst &mia7_bit,SPCOND_FLG(%a6) # was a7 changed?
+ bne.b uieh_div64_a7 # yes
+uieh_div64_dbyz:
+ btst &idbyz_bit,SPCOND_FLG(%a6) # did divide-by-zero occur?
+ bne.w uieh_divbyzero # yes
+ bra.w uieh_done # no
+uieh_div64_a7:
+ btst &0x5,EXC_ISR(%a6) # supervisor mode?
+ beq.b uieh_div64_dbyz # no
+# here, a7 has been incremented by 4 bytes in supervisor mode. we still
+# may have the following 3 cases:
+# (i) (a7)+
+# (ii) (a7)+; trace
+# (iii) (a7)+; divide-by-zero
+#
+ btst &idbyz_bit,SPCOND_FLG(%a6) # did divide-by-zero occur?
+ bne.w uieh_divbyzero_a7 # yes
+ tst.b EXC_ISR(%a6) # no; is trace enabled?
+ bmi.w uieh_trace_a7 # yes
+ bra.w uieh_a7 # no
+
+#
+# now, w/ group2, make movep's decode the fastest since it will
+# most likely be used the most.
+#
+uieh_group2:
+ btst &0x18,%d0 # test for not movep
+ beq.b uieh_not_movep
+
+
+ bsr.l _moveperipheral # _movep()
+ bra.w uieh_done
+
+uieh_not_movep:
+ btst &0x1b,%d0 # test for chk2,cmp2
+ beq.b uieh_chk2cmp2 # go handle chk2,cmp2
+
+ swap %d0 # put opword in lo word
+ cmpi.b %d0,&0xfc # test for cas2
+ beq.b uieh_cas2 # go handle cas2
+
+uieh_cas:
+
+ bsr.l _compandset # _cas()
+
+# the cases of "cas Dc,Du,(a7)+" and "cas Dc,Du,-(a7)" used from supervisor
+# mode are simply not considered valid and therefore are not handled.
+
+ bra.w uieh_done
+
+uieh_cas2:
+
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word # read extension word
+
+ tst.l %d1 # ifetch error?
+ bne.w isp_iacc # yes
+
+ bsr.l _compandset2 # _cas2()
+ bra.w uieh_done
+
+uieh_chk2cmp2:
+# chk2 may take a chk exception
+
+ bsr.l _chk2_cmp2 # _chk2_cmp2()
+
+# here we check to see if a chk trap should be taken
+ cmpi.b SPCOND_FLG(%a6),&ichk_flg
+ bne.w uieh_done
+ bra.b uieh_chk_trap
+
+###########################################################################
+
+#
+# the required emulation has been completed. now, clean up the necessary stack
+# info and prepare for rte
+#
+uieh_done:
+ mov.b EXC_CC+1(%a6),EXC_ISR+1(%a6) # insert new ccodes
+
+# if exception occurred in user mode, then we have to restore a7 in case it
+# changed. we don't have to update a7 for supervisor mose because that case
+# doesn't flow through here
+ btst &0x5,EXC_ISR(%a6) # user or supervisor?
+ bne.b uieh_finish # supervisor
+
+ mov.l EXC_A7(%a6),%a0 # fetch user stack pointer
+ mov.l %a0,%usp # restore it
+
+uieh_finish:
+ movm.l EXC_DREGS(%a6),&0x3fff # restore d0-d7/a0-a5
+
+ btst &0x7,EXC_ISR(%a6) # is trace mode on?
+ bne.b uieh_trace # yes;go handle trace mode
+
+ mov.l EXC_EXTWPTR(%a6),EXC_IPC(%a6) # new pc on stack frame
+ mov.l EXC_A6(%a6),(%a6) # prepare new a6 for unlink
+ unlk %a6 # unlink stack frame
+ bra.l _isp_done
+
+#
+# The instruction that was just emulated was also being traced. The trace
+# trap for this instruction will be lost unless we jump to the trace handler.
+# So, here we create a Trace Exception format number two exception stack
+# frame from the Unimplemented Integer Intruction Exception stack frame
+# format number zero and jump to the user supplied hook "_real_trace()".
+#
+# UIEH FRAME TRACE FRAME
+# ***************** *****************
+# * 0x0 * 0x0f4 * * Current *
+# ***************** * PC *
+# * Current * *****************
+# * PC * * 0x2 * 0x024 *
+# ***************** *****************
+# * SR * * Next *
+# ***************** * PC *
+# ->* Old * *****************
+# from link -->* A6 * * SR *
+# ***************** *****************
+# /* A7 * * New * <-- for final unlink
+# / * * * A6 *
+# link frame < ***************** *****************
+# \ ~ ~ ~ ~
+# \***************** *****************
+#
+uieh_trace:
+ mov.l EXC_A6(%a6),-0x4(%a6)
+ mov.w EXC_ISR(%a6),0x0(%a6)
+ mov.l EXC_IPC(%a6),0x8(%a6)
+ mov.l EXC_EXTWPTR(%a6),0x2(%a6)
+ mov.w &0x2024,0x6(%a6)
+ sub.l &0x4,%a6
+ unlk %a6
+ bra.l _real_trace
+
+#
+# UIEH FRAME CHK FRAME
+# ***************** *****************
+# * 0x0 * 0x0f4 * * Current *
+# ***************** * PC *
+# * Current * *****************
+# * PC * * 0x2 * 0x018 *
+# ***************** *****************
+# * SR * * Next *
+# ***************** * PC *
+# (4 words) *****************
+# * SR *
+# *****************
+# (6 words)
+#
+# the chk2 instruction should take a chk trap. so, here we must create a
+# chk stack frame from an unimplemented integer instruction exception frame
+# and jump to the user supplied entry point "_real_chk()".
+#
+uieh_chk_trap:
+ mov.b EXC_CC+1(%a6),EXC_ISR+1(%a6) # insert new ccodes
+ movm.l EXC_DREGS(%a6),&0x3fff # restore d0-d7/a0-a5
+
+ mov.w EXC_ISR(%a6),(%a6) # put new SR on stack
+ mov.l EXC_IPC(%a6),0x8(%a6) # put "Current PC" on stack
+ mov.l EXC_EXTWPTR(%a6),0x2(%a6) # put "Next PC" on stack
+ mov.w &0x2018,0x6(%a6) # put Vector Offset on stack
+
+ mov.l EXC_A6(%a6),%a6 # restore a6
+ add.l &LOCAL_SIZE,%sp # clear stack frame
+
+ bra.l _real_chk
+
+#
+# UIEH FRAME DIVBYZERO FRAME
+# ***************** *****************
+# * 0x0 * 0x0f4 * * Current *
+# ***************** * PC *
+# * Current * *****************
+# * PC * * 0x2 * 0x014 *
+# ***************** *****************
+# * SR * * Next *
+# ***************** * PC *
+# (4 words) *****************
+# * SR *
+# *****************
+# (6 words)
+#
+# the divide instruction should take an integer divide by zero trap. so, here
+# we must create a divbyzero stack frame from an unimplemented integer
+# instruction exception frame and jump to the user supplied entry point
+# "_real_divbyzero()".
+#
+uieh_divbyzero:
+ mov.b EXC_CC+1(%a6),EXC_ISR+1(%a6) # insert new ccodes
+ movm.l EXC_DREGS(%a6),&0x3fff # restore d0-d7/a0-a5
+
+ mov.w EXC_ISR(%a6),(%a6) # put new SR on stack
+ mov.l EXC_IPC(%a6),0x8(%a6) # put "Current PC" on stack
+ mov.l EXC_EXTWPTR(%a6),0x2(%a6) # put "Next PC" on stack
+ mov.w &0x2014,0x6(%a6) # put Vector Offset on stack
+
+ mov.l EXC_A6(%a6),%a6 # restore a6
+ add.l &LOCAL_SIZE,%sp # clear stack frame
+
+ bra.l _real_divbyzero
+
+#
+# DIVBYZERO FRAME
+# *****************
+# * Current *
+# UIEH FRAME * PC *
+# ***************** *****************
+# * 0x0 * 0x0f4 * * 0x2 * 0x014 *
+# ***************** *****************
+# * Current * * Next *
+# * PC * * PC *
+# ***************** *****************
+# * SR * * SR *
+# ***************** *****************
+# (4 words) (6 words)
+#
+# the divide instruction should take an integer divide by zero trap. so, here
+# we must create a divbyzero stack frame from an unimplemented integer
+# instruction exception frame and jump to the user supplied entry point
+# "_real_divbyzero()".
+#
+# However, we must also deal with the fact that (a7)+ was used from supervisor
+# mode, thereby shifting the stack frame up 4 bytes.
+#
+uieh_divbyzero_a7:
+ mov.b EXC_CC+1(%a6),EXC_ISR+1(%a6) # insert new ccodes
+ movm.l EXC_DREGS(%a6),&0x3fff # restore d0-d7/a0-a5
+
+ mov.l EXC_IPC(%a6),0xc(%a6) # put "Current PC" on stack
+ mov.w &0x2014,0xa(%a6) # put Vector Offset on stack
+ mov.l EXC_EXTWPTR(%a6),0x6(%a6) # put "Next PC" on stack
+
+ mov.l EXC_A6(%a6),%a6 # restore a6
+ add.l &4+LOCAL_SIZE,%sp # clear stack frame
+
+ bra.l _real_divbyzero
+
+#
+# TRACE FRAME
+# *****************
+# * Current *
+# UIEH FRAME * PC *
+# ***************** *****************
+# * 0x0 * 0x0f4 * * 0x2 * 0x024 *
+# ***************** *****************
+# * Current * * Next *
+# * PC * * PC *
+# ***************** *****************
+# * SR * * SR *
+# ***************** *****************
+# (4 words) (6 words)
+#
+#
+# The instruction that was just emulated was also being traced. The trace
+# trap for this instruction will be lost unless we jump to the trace handler.
+# So, here we create a Trace Exception format number two exception stack
+# frame from the Unimplemented Integer Intruction Exception stack frame
+# format number zero and jump to the user supplied hook "_real_trace()".
+#
+# However, we must also deal with the fact that (a7)+ was used from supervisor
+# mode, thereby shifting the stack frame up 4 bytes.
+#
+uieh_trace_a7:
+ mov.b EXC_CC+1(%a6),EXC_ISR+1(%a6) # insert new ccodes
+ movm.l EXC_DREGS(%a6),&0x3fff # restore d0-d7/a0-a5
+
+ mov.l EXC_IPC(%a6),0xc(%a6) # put "Current PC" on stack
+ mov.w &0x2024,0xa(%a6) # put Vector Offset on stack
+ mov.l EXC_EXTWPTR(%a6),0x6(%a6) # put "Next PC" on stack
+
+ mov.l EXC_A6(%a6),%a6 # restore a6
+ add.l &4+LOCAL_SIZE,%sp # clear stack frame
+
+ bra.l _real_trace
+
+#
+# UIEH FRAME
+# *****************
+# * 0x0 * 0x0f4 *
+# UIEH FRAME *****************
+# ***************** * Next *
+# * 0x0 * 0x0f4 * * PC *
+# ***************** *****************
+# * Current * * SR *
+# * PC * *****************
+# ***************** (4 words)
+# * SR *
+# *****************
+# (4 words)
+uieh_a7:
+ mov.b EXC_CC+1(%a6),EXC_ISR+1(%a6) # insert new ccodes
+ movm.l EXC_DREGS(%a6),&0x3fff # restore d0-d7/a0-a5
+
+ mov.w &0x00f4,0xe(%a6) # put Vector Offset on stack
+ mov.l EXC_EXTWPTR(%a6),0xa(%a6) # put "Next PC" on stack
+ mov.w EXC_ISR(%a6),0x8(%a6) # put SR on stack
+
+ mov.l EXC_A6(%a6),%a6 # restore a6
+ add.l &8+LOCAL_SIZE,%sp # clear stack frame
+ bra.l _isp_done
+
+##########
+
+# this is the exit point if a data read or write fails.
+# a0 = failing address
+# d0 = fslw
+isp_dacc:
+ mov.l %a0,(%a6) # save address
+ mov.l %d0,-0x4(%a6) # save partial fslw
+
+ lea -64(%a6),%sp
+ movm.l (%sp)+,&0x7fff # restore d0-d7/a0-a6
+
+ mov.l 0xc(%sp),-(%sp) # move voff,hi(pc)
+ mov.l 0x4(%sp),0x10(%sp) # store fslw
+ mov.l 0xc(%sp),0x4(%sp) # store sr,lo(pc)
+ mov.l 0x8(%sp),0xc(%sp) # store address
+ mov.l (%sp)+,0x4(%sp) # store voff,hi(pc)
+ mov.w &0x4008,0x6(%sp) # store new voff
+
+ bra.b isp_acc_exit
+
+# this is the exit point if an instruction word read fails.
+# FSLW:
+# misaligned = true
+# read = true
+# size = word
+# instruction = true
+# software emulation error = true
+isp_iacc:
+ movm.l EXC_DREGS(%a6),&0x3fff # restore d0-d7/a0-a5
+ unlk %a6 # unlink frame
+ sub.w &0x8,%sp # make room for acc frame
+ mov.l 0x8(%sp),(%sp) # store sr,lo(pc)
+ mov.w 0xc(%sp),0x4(%sp) # store hi(pc)
+ mov.w &0x4008,0x6(%sp) # store new voff
+ mov.l 0x2(%sp),0x8(%sp) # store address (=pc)
+ mov.l &0x09428001,0xc(%sp) # store fslw
+
+isp_acc_exit:
+ btst &0x5,(%sp) # user or supervisor?
+ beq.b isp_acc_exit2 # user
+ bset &0x2,0xd(%sp) # set supervisor TM bit
+isp_acc_exit2:
+ bra.l _real_access
+
+# if the addressing mode was (an)+ or -(an), the address register must
+# be restored to its pre-exception value before entering _real_access.
+isp_restore:
+ cmpi.b SPCOND_FLG(%a6),&restore_flg # do we need a restore?
+ bne.b isp_restore_done # no
+ clr.l %d0
+ mov.b EXC_SAVREG(%a6),%d0 # regno to restore
+ mov.l EXC_SAVVAL(%a6),(EXC_AREGS,%a6,%d0.l*4) # restore value
+isp_restore_done:
+ rts
+
+#########################################################################
+# XDEF **************************************************************** #
+# _calc_ea(): routine to calculate effective address #
+# #
+# XREF **************************************************************** #
+# _imem_read_word() - read instruction word #
+# _imem_read_long() - read instruction longword #
+# _dmem_read_long() - read data longword (for memory indirect) #
+# isp_iacc() - handle instruction access error exception #
+# isp_dacc() - handle data access error exception #
+# #
+# INPUT *************************************************************** #
+# d0 = number of bytes related to effective address (w,l) #
+# #
+# OUTPUT ************************************************************** #
+# If exiting through isp_dacc... #
+# a0 = failing address #
+# d0 = FSLW #
+# elsif exiting though isp_iacc... #
+# none #
+# else #
+# a0 = effective address #
+# #
+# ALGORITHM *********************************************************** #
+# The effective address type is decoded from the opword residing #
+# on the stack. A jump table is used to vector to a routine for the #
+# appropriate mode. Since none of the emulated integer instructions #
+# uses byte-sized operands, only handle word and long operations. #
+# #
+# Dn,An - shouldn't enter here #
+# (An) - fetch An value from stack #
+# -(An) - fetch An value from stack; return decr value; #
+# place decr value on stack; store old value in case of #
+# future access error; if -(a7), set mda7_flg in #
+# SPCOND_FLG #
+# (An)+ - fetch An value from stack; return value; #
+# place incr value on stack; store old value in case of #
+# future access error; if (a7)+, set mia7_flg in #
+# SPCOND_FLG #
+# (d16,An) - fetch An value from stack; read d16 using #
+# _imem_read_word(); fetch may fail -> branch to #
+# isp_iacc() #
+# (xxx).w,(xxx).l - use _imem_read_{word,long}() to fetch #
+# address; fetch may fail #
+# #<data> - return address of immediate value; set immed_flg #
+# in SPCOND_FLG #
+# (d16,PC) - fetch stacked PC value; read d16 using #
+# _imem_read_word(); fetch may fail -> branch to #
+# isp_iacc() #
+# everything else - read needed displacements as appropriate w/ #
+# _imem_read_{word,long}(); read may fail; if memory #
+# indirect, read indirect address using #
+# _dmem_read_long() which may also fail #
+# #
+#########################################################################
+
+ global _calc_ea
+_calc_ea:
+ mov.l %d0,%a0 # move # bytes to a0
+
+# MODE and REG are taken from the EXC_OPWORD.
+ mov.w EXC_OPWORD(%a6),%d0 # fetch opcode word
+ mov.w %d0,%d1 # make a copy
+
+ andi.w &0x3f,%d0 # extract mode field
+ andi.l &0x7,%d1 # extract reg field
+
+# jump to the corresponding function for each {MODE,REG} pair.
+ mov.w (tbl_ea_mode.b,%pc,%d0.w*2), %d0 # fetch jmp distance
+ jmp (tbl_ea_mode.b,%pc,%d0.w*1) # jmp to correct ea mode
+
+ swbeg &64
+tbl_ea_mode:
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+
+ short addr_ind_a0 - tbl_ea_mode
+ short addr_ind_a1 - tbl_ea_mode
+ short addr_ind_a2 - tbl_ea_mode
+ short addr_ind_a3 - tbl_ea_mode
+ short addr_ind_a4 - tbl_ea_mode
+ short addr_ind_a5 - tbl_ea_mode
+ short addr_ind_a6 - tbl_ea_mode
+ short addr_ind_a7 - tbl_ea_mode
+
+ short addr_ind_p_a0 - tbl_ea_mode
+ short addr_ind_p_a1 - tbl_ea_mode
+ short addr_ind_p_a2 - tbl_ea_mode
+ short addr_ind_p_a3 - tbl_ea_mode
+ short addr_ind_p_a4 - tbl_ea_mode
+ short addr_ind_p_a5 - tbl_ea_mode
+ short addr_ind_p_a6 - tbl_ea_mode
+ short addr_ind_p_a7 - tbl_ea_mode
+
+ short addr_ind_m_a0 - tbl_ea_mode
+ short addr_ind_m_a1 - tbl_ea_mode
+ short addr_ind_m_a2 - tbl_ea_mode
+ short addr_ind_m_a3 - tbl_ea_mode
+ short addr_ind_m_a4 - tbl_ea_mode
+ short addr_ind_m_a5 - tbl_ea_mode
+ short addr_ind_m_a6 - tbl_ea_mode
+ short addr_ind_m_a7 - tbl_ea_mode
+
+ short addr_ind_disp_a0 - tbl_ea_mode
+ short addr_ind_disp_a1 - tbl_ea_mode
+ short addr_ind_disp_a2 - tbl_ea_mode
+ short addr_ind_disp_a3 - tbl_ea_mode
+ short addr_ind_disp_a4 - tbl_ea_mode
+ short addr_ind_disp_a5 - tbl_ea_mode
+ short addr_ind_disp_a6 - tbl_ea_mode
+ short addr_ind_disp_a7 - tbl_ea_mode
+
+ short _addr_ind_ext - tbl_ea_mode
+ short _addr_ind_ext - tbl_ea_mode
+ short _addr_ind_ext - tbl_ea_mode
+ short _addr_ind_ext - tbl_ea_mode
+ short _addr_ind_ext - tbl_ea_mode
+ short _addr_ind_ext - tbl_ea_mode
+ short _addr_ind_ext - tbl_ea_mode
+ short _addr_ind_ext - tbl_ea_mode
+
+ short abs_short - tbl_ea_mode
+ short abs_long - tbl_ea_mode
+ short pc_ind - tbl_ea_mode
+ short pc_ind_ext - tbl_ea_mode
+ short immediate - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+ short tbl_ea_mode - tbl_ea_mode
+
+###################################
+# Address register indirect: (An) #
+###################################
+addr_ind_a0:
+ mov.l EXC_A0(%a6),%a0 # Get current a0
+ rts
+
+addr_ind_a1:
+ mov.l EXC_A1(%a6),%a0 # Get current a1
+ rts
+
+addr_ind_a2:
+ mov.l EXC_A2(%a6),%a0 # Get current a2
+ rts
+
+addr_ind_a3:
+ mov.l EXC_A3(%a6),%a0 # Get current a3
+ rts
+
+addr_ind_a4:
+ mov.l EXC_A4(%a6),%a0 # Get current a4
+ rts
+
+addr_ind_a5:
+ mov.l EXC_A5(%a6),%a0 # Get current a5
+ rts
+
+addr_ind_a6:
+ mov.l EXC_A6(%a6),%a0 # Get current a6
+ rts
+
+addr_ind_a7:
+ mov.l EXC_A7(%a6),%a0 # Get current a7
+ rts
+
+#####################################################
+# Address register indirect w/ postincrement: (An)+ #
+#####################################################
+addr_ind_p_a0:
+ mov.l %a0,%d0 # copy no. bytes
+ mov.l EXC_A0(%a6),%a0 # load current value
+ add.l %a0,%d0 # increment
+ mov.l %d0,EXC_A0(%a6) # save incremented value
+
+ mov.l %a0,EXC_SAVVAL(%a6) # save in case of access error
+ mov.b &0x0,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_p_a1:
+ mov.l %a0,%d0 # copy no. bytes
+ mov.l EXC_A1(%a6),%a0 # load current value
+ add.l %a0,%d0 # increment
+ mov.l %d0,EXC_A1(%a6) # save incremented value
+
+ mov.l %a0,EXC_SAVVAL(%a6) # save in case of access error
+ mov.b &0x1,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_p_a2:
+ mov.l %a0,%d0 # copy no. bytes
+ mov.l EXC_A2(%a6),%a0 # load current value
+ add.l %a0,%d0 # increment
+ mov.l %d0,EXC_A2(%a6) # save incremented value
+
+ mov.l %a0,EXC_SAVVAL(%a6) # save in case of access error
+ mov.b &0x2,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_p_a3:
+ mov.l %a0,%d0 # copy no. bytes
+ mov.l EXC_A3(%a6),%a0 # load current value
+ add.l %a0,%d0 # increment
+ mov.l %d0,EXC_A3(%a6) # save incremented value
+
+ mov.l %a0,EXC_SAVVAL(%a6) # save in case of access error
+ mov.b &0x3,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_p_a4:
+ mov.l %a0,%d0 # copy no. bytes
+ mov.l EXC_A4(%a6),%a0 # load current value
+ add.l %a0,%d0 # increment
+ mov.l %d0,EXC_A4(%a6) # save incremented value
+
+ mov.l %a0,EXC_SAVVAL(%a6) # save in case of access error
+ mov.b &0x4,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_p_a5:
+ mov.l %a0,%d0 # copy no. bytes
+ mov.l EXC_A5(%a6),%a0 # load current value
+ add.l %a0,%d0 # increment
+ mov.l %d0,EXC_A5(%a6) # save incremented value
+
+ mov.l %a0,EXC_SAVVAL(%a6) # save in case of access error
+ mov.b &0x5,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_p_a6:
+ mov.l %a0,%d0 # copy no. bytes
+ mov.l EXC_A6(%a6),%a0 # load current value
+ add.l %a0,%d0 # increment
+ mov.l %d0,EXC_A6(%a6) # save incremented value
+
+ mov.l %a0,EXC_SAVVAL(%a6) # save in case of access error
+ mov.b &0x6,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_p_a7:
+ mov.b &mia7_flg,SPCOND_FLG(%a6) # set "special case" flag
+
+ mov.l %a0,%d0 # copy no. bytes
+ mov.l EXC_A7(%a6),%a0 # load current value
+ add.l %a0,%d0 # increment
+ mov.l %d0,EXC_A7(%a6) # save incremented value
+ rts
+
+####################################################
+# Address register indirect w/ predecrement: -(An) #
+####################################################
+addr_ind_m_a0:
+ mov.l EXC_A0(%a6),%d0 # Get current a0
+ mov.l %d0,EXC_SAVVAL(%a6) # save in case of access error
+ sub.l %a0,%d0 # Decrement
+ mov.l %d0,EXC_A0(%a6) # Save decr value
+ mov.l %d0,%a0
+
+ mov.b &0x0,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_m_a1:
+ mov.l EXC_A1(%a6),%d0 # Get current a1
+ mov.l %d0,EXC_SAVVAL(%a6) # save in case of access error
+ sub.l %a0,%d0 # Decrement
+ mov.l %d0,EXC_A1(%a6) # Save decr value
+ mov.l %d0,%a0
+
+ mov.b &0x1,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_m_a2:
+ mov.l EXC_A2(%a6),%d0 # Get current a2
+ mov.l %d0,EXC_SAVVAL(%a6) # save in case of access error
+ sub.l %a0,%d0 # Decrement
+ mov.l %d0,EXC_A2(%a6) # Save decr value
+ mov.l %d0,%a0
+
+ mov.b &0x2,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_m_a3:
+ mov.l EXC_A3(%a6),%d0 # Get current a3
+ mov.l %d0,EXC_SAVVAL(%a6) # save in case of access error
+ sub.l %a0,%d0 # Decrement
+ mov.l %d0,EXC_A3(%a6) # Save decr value
+ mov.l %d0,%a0
+
+ mov.b &0x3,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_m_a4:
+ mov.l EXC_A4(%a6),%d0 # Get current a4
+ mov.l %d0,EXC_SAVVAL(%a6) # save in case of access error
+ sub.l %a0,%d0 # Decrement
+ mov.l %d0,EXC_A4(%a6) # Save decr value
+ mov.l %d0,%a0
+
+ mov.b &0x4,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_m_a5:
+ mov.l EXC_A5(%a6),%d0 # Get current a5
+ mov.l %d0,EXC_SAVVAL(%a6) # save in case of access error
+ sub.l %a0,%d0 # Decrement
+ mov.l %d0,EXC_A5(%a6) # Save decr value
+ mov.l %d0,%a0
+
+ mov.b &0x5,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_m_a6:
+ mov.l EXC_A6(%a6),%d0 # Get current a6
+ mov.l %d0,EXC_SAVVAL(%a6) # save in case of access error
+ sub.l %a0,%d0 # Decrement
+ mov.l %d0,EXC_A6(%a6) # Save decr value
+ mov.l %d0,%a0
+
+ mov.b &0x6,EXC_SAVREG(%a6) # save regno, too
+ mov.b &restore_flg,SPCOND_FLG(%a6) # set flag
+ rts
+
+addr_ind_m_a7:
+ mov.b &mda7_flg,SPCOND_FLG(%a6) # set "special case" flag
+
+ mov.l EXC_A7(%a6),%d0 # Get current a7
+ sub.l %a0,%d0 # Decrement
+ mov.l %d0,EXC_A7(%a6) # Save decr value
+ mov.l %d0,%a0
+ rts
+
+########################################################
+# Address register indirect w/ displacement: (d16, An) #
+########################################################
+addr_ind_disp_a0:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+ add.l EXC_A0(%a6),%a0 # a0 + d16
+ rts
+
+addr_ind_disp_a1:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+ add.l EXC_A1(%a6),%a0 # a1 + d16
+ rts
+
+addr_ind_disp_a2:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+ add.l EXC_A2(%a6),%a0 # a2 + d16
+ rts
+
+addr_ind_disp_a3:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+ add.l EXC_A3(%a6),%a0 # a3 + d16
+ rts
+
+addr_ind_disp_a4:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+ add.l EXC_A4(%a6),%a0 # a4 + d16
+ rts
+
+addr_ind_disp_a5:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+ add.l EXC_A5(%a6),%a0 # a5 + d16
+ rts
+
+addr_ind_disp_a6:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+ add.l EXC_A6(%a6),%a0 # a6 + d16
+ rts
+
+addr_ind_disp_a7:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+ add.l EXC_A7(%a6),%a0 # a7 + d16
+ rts
+
+########################################################################
+# Address register indirect w/ index(8-bit displacement): (dn, An, Xn) #
+# " " " w/ " (base displacement): (bd, An, Xn) #
+# Memory indirect postindexed: ([bd, An], Xn, od) #
+# Memory indirect preindexed: ([bd, An, Xn], od) #
+########################################################################
+_addr_ind_ext:
+ mov.l %d1,-(%sp)
+
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word # fetch extword in d0
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.l (%sp)+,%d1
+
+ mov.l (EXC_AREGS,%a6,%d1.w*4),%a0 # put base in a0
+
+ btst &0x8,%d0
+ beq.b addr_ind_index_8bit # for ext word or not?
+
+ movm.l &0x3c00,-(%sp) # save d2-d5
+
+ mov.l %d0,%d5 # put extword in d5
+ mov.l %a0,%d3 # put base in d3
+
+ bra.l calc_mem_ind # calc memory indirect
+
+addr_ind_index_8bit:
+ mov.l %d2,-(%sp) # save old d2
+
+ mov.l %d0,%d1
+ rol.w &0x4,%d1
+ andi.w &0xf,%d1 # extract index regno
+
+ mov.l (EXC_DREGS,%a6,%d1.w*4),%d1 # fetch index reg value
+
+ btst &0xb,%d0 # is it word or long?
+ bne.b aii8_long
+ ext.l %d1 # sign extend word index
+aii8_long:
+ mov.l %d0,%d2
+ rol.w &0x7,%d2
+ andi.l &0x3,%d2 # extract scale value
+
+ lsl.l %d2,%d1 # shift index by scale
+
+ extb.l %d0 # sign extend displacement
+ add.l %d1,%d0 # index + disp
+ add.l %d0,%a0 # An + (index + disp)
+
+ mov.l (%sp)+,%d2 # restore old d2
+ rts
+
+######################
+# Immediate: #<data> #
+#########################################################################
+# word, long: <ea> of the data is the current extension word #
+# pointer value. new extension word pointer is simply the old #
+# plus the number of bytes in the data type(2 or 4). #
+#########################################################################
+immediate:
+ mov.b &immed_flg,SPCOND_FLG(%a6) # set immediate flag
+
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch extension word ptr
+ rts
+
+###########################
+# Absolute short: (XXX).W #
+###########################
+abs_short:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word # fetch short address
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # return <ea> in a0
+ rts
+
+##########################
+# Absolute long: (XXX).L #
+##########################
+abs_long:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_long # fetch long address
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.l %d0,%a0 # return <ea> in a0
+ rts
+
+#######################################################
+# Program counter indirect w/ displacement: (d16, PC) #
+#######################################################
+pc_ind:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word # fetch word displacement
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.w %d0,%a0 # sign extend displacement
+
+ add.l EXC_EXTWPTR(%a6),%a0 # pc + d16
+
+# _imem_read_word() increased the extwptr by 2. need to adjust here.
+ subq.l &0x2,%a0 # adjust <ea>
+
+ rts
+
+##########################################################
+# PC indirect w/ index(8-bit displacement): (d8, PC, An) #
+# " " w/ " (base displacement): (bd, PC, An) #
+# PC memory indirect postindexed: ([bd, PC], Xn, od) #
+# PC memory indirect preindexed: ([bd, PC, Xn], od) #
+##########################################################
+pc_ind_ext:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word # fetch ext word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.l EXC_EXTWPTR(%a6),%a0 # put base in a0
+ subq.l &0x2,%a0 # adjust base
+
+ btst &0x8,%d0 # is disp only 8 bits?
+ beq.b pc_ind_index_8bit # yes
+
+# the indexed addressing mode uses a base displacement of size
+# word or long
+ movm.l &0x3c00,-(%sp) # save d2-d5
+
+ mov.l %d0,%d5 # put extword in d5
+ mov.l %a0,%d3 # put base in d3
+
+ bra.l calc_mem_ind # calc memory indirect
+
+pc_ind_index_8bit:
+ mov.l %d2,-(%sp) # create a temp register
+
+ mov.l %d0,%d1 # make extword copy
+ rol.w &0x4,%d1 # rotate reg num into place
+ andi.w &0xf,%d1 # extract register number
+
+ mov.l (EXC_DREGS,%a6,%d1.w*4),%d1 # fetch index reg value
+
+ btst &0xb,%d0 # is index word or long?
+ bne.b pii8_long # long
+ ext.l %d1 # sign extend word index
+pii8_long:
+ mov.l %d0,%d2 # make extword copy
+ rol.w &0x7,%d2 # rotate scale value into place
+ andi.l &0x3,%d2 # extract scale value
+
+ lsl.l %d2,%d1 # shift index by scale
+
+ extb.l %d0 # sign extend displacement
+ add.l %d1,%d0 # index + disp
+ add.l %d0,%a0 # An + (index + disp)
+
+ mov.l (%sp)+,%d2 # restore temp register
+
+ rts
+
+# a5 = exc_extwptr (global to uaeh)
+# a4 = exc_opword (global to uaeh)
+# a3 = exc_dregs (global to uaeh)
+
+# d2 = index (internal " " )
+# d3 = base (internal " " )
+# d4 = od (internal " " )
+# d5 = extword (internal " " )
+calc_mem_ind:
+ btst &0x6,%d5 # is the index suppressed?
+ beq.b calc_index
+ clr.l %d2 # yes, so index = 0
+ bra.b base_supp_ck
+calc_index:
+ bfextu %d5{&16:&4},%d2
+ mov.l (EXC_DREGS,%a6,%d2.w*4),%d2
+ btst &0xb,%d5 # is index word or long?
+ bne.b no_ext
+ ext.l %d2
+no_ext:
+ bfextu %d5{&21:&2},%d0
+ lsl.l %d0,%d2
+base_supp_ck:
+ btst &0x7,%d5 # is the bd suppressed?
+ beq.b no_base_sup
+ clr.l %d3
+no_base_sup:
+ bfextu %d5{&26:&2},%d0 # get bd size
+# beq.l _error # if (size == 0) it's reserved
+ cmpi.b %d0,&2
+ blt.b no_bd
+ beq.b get_word_bd
+
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_long
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ bra.b chk_ind
+get_word_bd:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ ext.l %d0 # sign extend bd
+
+chk_ind:
+ add.l %d0,%d3 # base += bd
+no_bd:
+ bfextu %d5{&30:&2},%d0 # is od suppressed?
+ beq.w aii_bd
+ cmpi.b %d0,&0x2
+ blt.b null_od
+ beq.b word_od
+
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x4,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_long
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ bra.b add_them
+
+word_od:
+ mov.l EXC_EXTWPTR(%a6),%a0 # fetch instruction addr
+ addq.l &0x2,EXC_EXTWPTR(%a6) # incr instruction ptr
+ bsr.l _imem_read_word
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ ext.l %d0 # sign extend od
+ bra.b add_them
+
+null_od:
+ clr.l %d0
+add_them:
+ mov.l %d0,%d4
+ btst &0x2,%d5 # pre or post indexing?
+ beq.b pre_indexed
+
+ mov.l %d3,%a0
+ bsr.l _dmem_read_long
+
+ tst.l %d1 # dfetch error?
+ bne.b calc_ea_err # yes
+
+ add.l %d2,%d0 # <ea> += index
+ add.l %d4,%d0 # <ea> += od
+ bra.b done_ea
+
+pre_indexed:
+ add.l %d2,%d3 # preindexing
+ mov.l %d3,%a0
+ bsr.l _dmem_read_long
+
+ tst.l %d1 # ifetch error?
+ bne.b calc_ea_err # yes
+
+ add.l %d4,%d0 # ea += od
+ bra.b done_ea
+
+aii_bd:
+ add.l %d2,%d3 # ea = (base + bd) + index
+ mov.l %d3,%d0
+done_ea:
+ mov.l %d0,%a0
+
+ movm.l (%sp)+,&0x003c # restore d2-d5
+ rts
+
+# if dmem_read_long() returns a fail message in d1, the package
+# must create an access error frame. here, we pass a skeleton fslw
+# and the failing address to the routine that creates the new frame.
+# FSLW:
+# read = true
+# size = longword
+# TM = data
+# software emulation error = true
+calc_ea_err:
+ mov.l %d3,%a0 # pass failing address
+ mov.l &0x01010001,%d0 # pass fslw
+ bra.l isp_dacc
+
+#########################################################################
+# XDEF **************************************************************** #
+# _moveperipheral(): routine to emulate movep instruction #
+# #
+# XREF **************************************************************** #
+# _dmem_read_byte() - read byte from memory #
+# _dmem_write_byte() - write byte to memory #
+# isp_dacc() - handle data access error exception #
+# #
+# INPUT *************************************************************** #
+# none #
+# #
+# OUTPUT ************************************************************** #
+# If exiting through isp_dacc... #
+# a0 = failing address #
+# d0 = FSLW #
+# else #
+# none #
+# #
+# ALGORITHM *********************************************************** #
+# Decode the movep instruction words stored at EXC_OPWORD and #
+# either read or write the required bytes from/to memory. Use the #
+# _dmem_{read,write}_byte() routines. If one of the memory routines #
+# returns a failing value, we must pass the failing address and a FSLW #
+# to the _isp_dacc() routine. #
+# Since this instruction is used to access peripherals, make sure #
+# to only access the required bytes. #
+# #
+#########################################################################
+
+###########################
+# movep.(w,l) Dx,(d,Ay) #
+# movep.(w,l) (d,Ay),Dx #
+###########################
+ global _moveperipheral
+_moveperipheral:
+ mov.w EXC_OPWORD(%a6),%d1 # fetch the opcode word
+
+ mov.b %d1,%d0
+ and.w &0x7,%d0 # extract Ay from opcode word
+
+ mov.l (EXC_AREGS,%a6,%d0.w*4),%a0 # fetch ay
+
+ add.w EXC_EXTWORD(%a6),%a0 # add: an + sgn_ext(disp)
+
+ btst &0x7,%d1 # (reg 2 mem) or (mem 2 reg)
+ beq.w mem2reg
+
+# reg2mem: fetch dx, then write it to memory
+reg2mem:
+ mov.w %d1,%d0
+ rol.w &0x7,%d0
+ and.w &0x7,%d0 # extract Dx from opcode word
+
+ mov.l (EXC_DREGS,%a6,%d0.w*4), %d0 # fetch dx
+
+ btst &0x6,%d1 # word or long operation?
+ beq.b r2mwtrans
+
+# a0 = dst addr
+# d0 = Dx
+r2mltrans:
+ mov.l %d0,%d2 # store data
+ mov.l %a0,%a2 # store addr
+ rol.l &0x8,%d2
+ mov.l %d2,%d0
+
+ bsr.l _dmem_write_byte # os : write hi
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_write_err # yes
+
+ add.w &0x2,%a2 # incr addr
+ mov.l %a2,%a0
+ rol.l &0x8,%d2
+ mov.l %d2,%d0
+
+ bsr.l _dmem_write_byte # os : write lo
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_write_err # yes
+
+ add.w &0x2,%a2 # incr addr
+ mov.l %a2,%a0
+ rol.l &0x8,%d2
+ mov.l %d2,%d0
+
+ bsr.l _dmem_write_byte # os : write lo
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_write_err # yes
+
+ add.w &0x2,%a2 # incr addr
+ mov.l %a2,%a0
+ rol.l &0x8,%d2
+ mov.l %d2,%d0
+
+ bsr.l _dmem_write_byte # os : write lo
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_write_err # yes
+
+ rts
+
+# a0 = dst addr
+# d0 = Dx
+r2mwtrans:
+ mov.l %d0,%d2 # store data
+ mov.l %a0,%a2 # store addr
+ lsr.w &0x8,%d0
+
+ bsr.l _dmem_write_byte # os : write hi
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_write_err # yes
+
+ add.w &0x2,%a2
+ mov.l %a2,%a0
+ mov.l %d2,%d0
+
+ bsr.l _dmem_write_byte # os : write lo
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_write_err # yes
+
+ rts
+
+# mem2reg: read bytes from memory.
+# determines the dest register, and then writes the bytes into it.
+mem2reg:
+ btst &0x6,%d1 # word or long operation?
+ beq.b m2rwtrans
+
+# a0 = dst addr
+m2rltrans:
+ mov.l %a0,%a2 # store addr
+
+ bsr.l _dmem_read_byte # read first byte
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_read_err # yes
+
+ mov.l %d0,%d2
+
+ add.w &0x2,%a2 # incr addr by 2 bytes
+ mov.l %a2,%a0
+
+ bsr.l _dmem_read_byte # read second byte
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_read_err # yes
+
+ lsl.w &0x8,%d2
+ mov.b %d0,%d2 # append bytes
+
+ add.w &0x2,%a2 # incr addr by 2 bytes
+ mov.l %a2,%a0
+
+ bsr.l _dmem_read_byte # read second byte
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_read_err # yes
+
+ lsl.l &0x8,%d2
+ mov.b %d0,%d2 # append bytes
+
+ add.w &0x2,%a2 # incr addr by 2 bytes
+ mov.l %a2,%a0
+
+ bsr.l _dmem_read_byte # read second byte
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_read_err # yes
+
+ lsl.l &0x8,%d2
+ mov.b %d0,%d2 # append bytes
+
+ mov.b EXC_OPWORD(%a6),%d1
+ lsr.b &0x1,%d1
+ and.w &0x7,%d1 # extract Dx from opcode word
+
+ mov.l %d2,(EXC_DREGS,%a6,%d1.w*4) # store dx
+
+ rts
+
+# a0 = dst addr
+m2rwtrans:
+ mov.l %a0,%a2 # store addr
+
+ bsr.l _dmem_read_byte # read first byte
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_read_err # yes
+
+ mov.l %d0,%d2
+
+ add.w &0x2,%a2 # incr addr by 2 bytes
+ mov.l %a2,%a0
+
+ bsr.l _dmem_read_byte # read second byte
+
+ tst.l %d1 # dfetch error?
+ bne.w movp_read_err # yes
+
+ lsl.w &0x8,%d2
+ mov.b %d0,%d2 # append bytes
+
+ mov.b EXC_OPWORD(%a6),%d1
+ lsr.b &0x1,%d1
+ and.w &0x7,%d1 # extract Dx from opcode word
+
+ mov.w %d2,(EXC_DREGS+2,%a6,%d1.w*4) # store dx
+
+ rts
+
+# if dmem_{read,write}_byte() returns a fail message in d1, the package
+# must create an access error frame. here, we pass a skeleton fslw
+# and the failing address to the routine that creates the new frame.
+# FSLW:
+# write = true
+# size = byte
+# TM = data
+# software emulation error = true
+movp_write_err:
+ mov.l %a2,%a0 # pass failing address
+ mov.l &0x00a10001,%d0 # pass fslw
+ bra.l isp_dacc
+
+# FSLW:
+# read = true
+# size = byte
+# TM = data
+# software emulation error = true
+movp_read_err:
+ mov.l %a2,%a0 # pass failing address
+ mov.l &0x01210001,%d0 # pass fslw
+ bra.l isp_dacc
+
+#########################################################################
+# XDEF **************************************************************** #
+# _chk2_cmp2(): routine to emulate chk2/cmp2 instructions #
+# #
+# XREF **************************************************************** #
+# _calc_ea(): calculate effective address #
+# _dmem_read_long(): read operands #
+# _dmem_read_word(): read operands #
+# isp_dacc(): handle data access error exception #
+# #
+# INPUT *************************************************************** #
+# none #
+# #
+# OUTPUT ************************************************************** #
+# If exiting through isp_dacc... #
+# a0 = failing address #
+# d0 = FSLW #
+# else #
+# none #
+# #
+# ALGORITHM *********************************************************** #
+# First, calculate the effective address, then fetch the byte, #
+# word, or longword sized operands. Then, in the interest of #
+# simplicity, all operands are converted to longword size whether the #
+# operation is byte, word, or long. The bounds are sign extended #
+# accordingly. If Rn is a data regsiter, Rn is also sign extended. If #
+# Rn is an address register, it need not be sign extended since the #
+# full register is always used. #
+# The comparisons are made and the condition codes calculated. #
+# If the instruction is chk2 and the Rn value is out-of-bounds, set #
+# the ichk_flg in SPCOND_FLG. #
+# If the memory fetch returns a failing value, pass the failing #
+# address and FSLW to the isp_dacc() routine. #
+# #
+#########################################################################
+
+ global _chk2_cmp2
+_chk2_cmp2:
+
+# passing size parameter doesn't matter since chk2 & cmp2 can't do
+# either predecrement, postincrement, or immediate.
+ bsr.l _calc_ea # calculate <ea>
+
+ mov.b EXC_EXTWORD(%a6), %d0 # fetch hi extension word
+ rol.b &0x4, %d0 # rotate reg bits into lo
+ and.w &0xf, %d0 # extract reg bits
+
+ mov.l (EXC_DREGS,%a6,%d0.w*4), %d2 # get regval
+
+ cmpi.b EXC_OPWORD(%a6), &0x2 # what size is operation?
+ blt.b chk2_cmp2_byte # size == byte
+ beq.b chk2_cmp2_word # size == word
+
+# the bounds are longword size. call routine to read the lower
+# bound into d0 and the higher bound into d1.
+chk2_cmp2_long:
+ mov.l %a0,%a2 # save copy of <ea>
+ bsr.l _dmem_read_long # fetch long lower bound
+
+ tst.l %d1 # dfetch error?
+ bne.w chk2_cmp2_err_l # yes
+
+ mov.l %d0,%d3 # save long lower bound
+ addq.l &0x4,%a2
+ mov.l %a2,%a0 # pass <ea> of long upper bound
+ bsr.l _dmem_read_long # fetch long upper bound
+
+ tst.l %d1 # dfetch error?
+ bne.w chk2_cmp2_err_l # yes
+
+ mov.l %d0,%d1 # long upper bound in d1
+ mov.l %d3,%d0 # long lower bound in d0
+ bra.w chk2_cmp2_compare # go do the compare emulation
+
+# the bounds are word size. fetch them in one subroutine call by
+# reading a longword. sign extend both. if it's a data operation,
+# sign extend Rn to long, also.
+chk2_cmp2_word:
+ mov.l %a0,%a2
+ bsr.l _dmem_read_long # fetch 2 word bounds
+
+ tst.l %d1 # dfetch error?
+ bne.w chk2_cmp2_err_l # yes
+
+ mov.w %d0, %d1 # place hi in %d1
+ swap %d0 # place lo in %d0
+
+ ext.l %d0 # sign extend lo bnd
+ ext.l %d1 # sign extend hi bnd
+
+ btst &0x7, EXC_EXTWORD(%a6) # address compare?
+ bne.w chk2_cmp2_compare # yes; don't sign extend
+
+# operation is a data register compare.
+# sign extend word to long so we can do simple longword compares.
+ ext.l %d2 # sign extend data word
+ bra.w chk2_cmp2_compare # go emulate compare
+
+# the bounds are byte size. fetch them in one subroutine call by
+# reading a word. sign extend both. if it's a data operation,
+# sign extend Rn to long, also.
+chk2_cmp2_byte:
+ mov.l %a0,%a2
+ bsr.l _dmem_read_word # fetch 2 byte bounds
+
+ tst.l %d1 # dfetch error?
+ bne.w chk2_cmp2_err_w # yes
+
+ mov.b %d0, %d1 # place hi in %d1
+ lsr.w &0x8, %d0 # place lo in %d0
+
+ extb.l %d0 # sign extend lo bnd
+ extb.l %d1 # sign extend hi bnd
+
+ btst &0x7, EXC_EXTWORD(%a6) # address compare?
+ bne.b chk2_cmp2_compare # yes; don't sign extend
+
+# operation is a data register compare.
+# sign extend byte to long so we can do simple longword compares.
+ extb.l %d2 # sign extend data byte
+
+#
+# To set the ccodes correctly:
+# (1) save 'Z' bit from (Rn - lo)
+# (2) save 'Z' and 'N' bits from ((hi - lo) - (Rn - hi))
+# (3) keep 'X', 'N', and 'V' from before instruction
+# (4) combine ccodes
+#
+chk2_cmp2_compare:
+ sub.l %d0, %d2 # (Rn - lo)
+ mov.w %cc, %d3 # fetch resulting ccodes
+ andi.b &0x4, %d3 # keep 'Z' bit
+ sub.l %d0, %d1 # (hi - lo)
+ cmp.l %d1,%d2 # ((hi - lo) - (Rn - hi))
+
+ mov.w %cc, %d4 # fetch resulting ccodes
+ or.b %d4, %d3 # combine w/ earlier ccodes
+ andi.b &0x5, %d3 # keep 'Z' and 'N'
+
+ mov.w EXC_CC(%a6), %d4 # fetch old ccodes
+ andi.b &0x1a, %d4 # keep 'X','N','V' bits
+ or.b %d3, %d4 # insert new ccodes
+ mov.w %d4, EXC_CC(%a6) # save new ccodes
+
+ btst &0x3, EXC_EXTWORD(%a6) # separate chk2,cmp2
+ bne.b chk2_finish # it's a chk2
+
+ rts
+
+# this code handles the only difference between chk2 and cmp2. chk2 would
+# have trapped out if the value was out of bounds. we check this by seeing
+# if the 'N' bit was set by the operation.
+chk2_finish:
+ btst &0x0, %d4 # is 'N' bit set?
+ bne.b chk2_trap # yes;chk2 should trap
+ rts
+chk2_trap:
+ mov.b &ichk_flg,SPCOND_FLG(%a6) # set "special case" flag
+ rts
+
+# if dmem_read_{long,word}() returns a fail message in d1, the package
+# must create an access error frame. here, we pass a skeleton fslw
+# and the failing address to the routine that creates the new frame.
+# FSLW:
+# read = true
+# size = longword
+# TM = data
+# software emulation error = true
+chk2_cmp2_err_l:
+ mov.l %a2,%a0 # pass failing address
+ mov.l &0x01010001,%d0 # pass fslw
+ bra.l isp_dacc
+
+# FSLW:
+# read = true
+# size = word
+# TM = data
+# software emulation error = true
+chk2_cmp2_err_w:
+ mov.l %a2,%a0 # pass failing address
+ mov.l &0x01410001,%d0 # pass fslw
+ bra.l isp_dacc
+
+#########################################################################
+# XDEF **************************************************************** #
+# _div64(): routine to emulate div{u,s}.l <ea>,Dr:Dq #
+# 64/32->32r:32q #
+# #
+# XREF **************************************************************** #
+# _calc_ea() - calculate effective address #
+# isp_iacc() - handle instruction access error exception #
+# isp_dacc() - handle data access error exception #
+# isp_restore() - restore An on access error w/ -() or ()+ #
+# #
+# INPUT *************************************************************** #
+# none #
+# #
+# OUTPUT ************************************************************** #
+# If exiting through isp_dacc... #
+# a0 = failing address #
+# d0 = FSLW #
+# else #
+# none #
+# #
+# ALGORITHM *********************************************************** #
+# First, decode the operand location. If it's in Dn, fetch from #
+# the stack. If it's in memory, use _calc_ea() to calculate the #
+# effective address. Use _dmem_read_long() to fetch at that address. #
+# Unless the operand is immediate data. Then use _imem_read_long(). #
+# Send failures to isp_dacc() or isp_iacc() as appropriate. #
+# If the operands are signed, make them unsigned and save the #
+# sign info for later. Separate out special cases like divide-by-zero #
+# or 32-bit divides if possible. Else, use a special math algorithm #
+# to calculate the result. #
+# Restore sign info if signed instruction. Set the condition #
+# codes. Set idbyz_flg in SPCOND_FLG if divisor was zero. Store the #
+# quotient and remainder in the appropriate data registers on the stack.#
+# #
+#########################################################################
+
+set NDIVISOR, EXC_TEMP+0x0
+set NDIVIDEND, EXC_TEMP+0x1
+set NDRSAVE, EXC_TEMP+0x2
+set NDQSAVE, EXC_TEMP+0x4
+set DDSECOND, EXC_TEMP+0x6
+set DDQUOTIENT, EXC_TEMP+0x8
+set DDNORMAL, EXC_TEMP+0xc
+
+ global _div64
+#############
+# div(u,s)l #
+#############
+_div64:
+ mov.b EXC_OPWORD+1(%a6), %d0
+ andi.b &0x38, %d0 # extract src mode
+
+ bne.w dcontrolmodel_s # %dn dest or control mode?
+
+ mov.b EXC_OPWORD+1(%a6), %d0 # extract Dn from opcode
+ andi.w &0x7, %d0
+ mov.l (EXC_DREGS,%a6,%d0.w*4), %d7 # fetch divisor from register
+
+dgotsrcl:
+ beq.w div64eq0 # divisor is = 0!!!
+
+ mov.b EXC_EXTWORD+1(%a6), %d0 # extract Dr from extword
+ mov.b EXC_EXTWORD(%a6), %d1 # extract Dq from extword
+ and.w &0x7, %d0
+ lsr.b &0x4, %d1
+ and.w &0x7, %d1
+ mov.w %d0, NDRSAVE(%a6) # save Dr for later
+ mov.w %d1, NDQSAVE(%a6) # save Dq for later
+
+# fetch %dr and %dq directly off stack since all regs are saved there
+ mov.l (EXC_DREGS,%a6,%d0.w*4), %d5 # get dividend hi
+ mov.l (EXC_DREGS,%a6,%d1.w*4), %d6 # get dividend lo
+
+# separate signed and unsigned divide
+ btst &0x3, EXC_EXTWORD(%a6) # signed or unsigned?
+ beq.b dspecialcases # use positive divide
+
+# save the sign of the divisor
+# make divisor unsigned if it's negative
+ tst.l %d7 # chk sign of divisor
+ slt NDIVISOR(%a6) # save sign of divisor
+ bpl.b dsgndividend
+ neg.l %d7 # complement negative divisor
+
+# save the sign of the dividend
+# make dividend unsigned if it's negative
+dsgndividend:
+ tst.l %d5 # chk sign of hi(dividend)
+ slt NDIVIDEND(%a6) # save sign of dividend
+ bpl.b dspecialcases
+
+ mov.w &0x0, %cc # clear 'X' cc bit
+ negx.l %d6 # complement signed dividend
+ negx.l %d5
+
+# extract some special cases:
+# - is (dividend == 0) ?
+# - is (hi(dividend) == 0 && (divisor <= lo(dividend))) ? (32-bit div)
+dspecialcases:
+ tst.l %d5 # is (hi(dividend) == 0)
+ bne.b dnormaldivide # no, so try it the long way
+
+ tst.l %d6 # is (lo(dividend) == 0), too
+ beq.w ddone # yes, so (dividend == 0)
+
+ cmp.l %d7,%d6 # is (divisor <= lo(dividend))
+ bls.b d32bitdivide # yes, so use 32 bit divide
+
+ exg %d5,%d6 # q = 0, r = dividend
+ bra.w divfinish # can't divide, we're done.
+
+d32bitdivide:
+ tdivu.l %d7, %d5:%d6 # it's only a 32/32 bit div!
+
+ bra.b divfinish
+
+dnormaldivide:
+# last special case:
+# - is hi(dividend) >= divisor ? if yes, then overflow
+ cmp.l %d7,%d5
+ bls.b ddovf # answer won't fit in 32 bits
+
+# perform the divide algorithm:
+ bsr.l dclassical # do int divide
+
+# separate into signed and unsigned finishes.
+divfinish:
+ btst &0x3, EXC_EXTWORD(%a6) # do divs, divu separately
+ beq.b ddone # divu has no processing!!!
+
+# it was a divs.l, so ccode setting is a little more complicated...
+ tst.b NDIVIDEND(%a6) # remainder has same sign
+ beq.b dcc # as dividend.
+ neg.l %d5 # sgn(rem) = sgn(dividend)
+dcc:
+ mov.b NDIVISOR(%a6), %d0
+ eor.b %d0, NDIVIDEND(%a6) # chk if quotient is negative
+ beq.b dqpos # branch to quot positive
+
+# 0x80000000 is the largest number representable as a 32-bit negative
+# number. the negative of 0x80000000 is 0x80000000.
+ cmpi.l %d6, &0x80000000 # will (-quot) fit in 32 bits?
+ bhi.b ddovf
+
+ neg.l %d6 # make (-quot) 2's comp
+
+ bra.b ddone
+
+dqpos:
+ btst &0x1f, %d6 # will (+quot) fit in 32 bits?
+ bne.b ddovf
+
+ddone:
+# at this point, result is normal so ccodes are set based on result.
+ mov.w EXC_CC(%a6), %cc
+ tst.l %d6 # set %ccode bits
+ mov.w %cc, EXC_CC(%a6)
+
+ mov.w NDRSAVE(%a6), %d0 # get Dr off stack
+ mov.w NDQSAVE(%a6), %d1 # get Dq off stack
+
+# if the register numbers are the same, only the quotient gets saved.
+# so, if we always save the quotient second, we save ourselves a cmp&beq
+ mov.l %d5, (EXC_DREGS,%a6,%d0.w*4) # save remainder
+ mov.l %d6, (EXC_DREGS,%a6,%d1.w*4) # save quotient
+
+ rts
+
+ddovf:
+ bset &0x1, EXC_CC+1(%a6) # 'V' set on overflow
+ bclr &0x0, EXC_CC+1(%a6) # 'C' cleared on overflow
+
+ rts
+
+div64eq0:
+ andi.b &0x1e, EXC_CC+1(%a6) # clear 'C' bit on divbyzero
+ ori.b &idbyz_flg,SPCOND_FLG(%a6) # set "special case" flag
+ rts
+
+###########################################################################
+#########################################################################
+# This routine uses the 'classical' Algorithm D from Donald Knuth's #
+# Art of Computer Programming, vol II, Seminumerical Algorithms. #
+# For this implementation b=2**16, and the target is U1U2U3U4/V1V2, #
+# where U,V are words of the quadword dividend and longword divisor, #
+# and U1, V1 are the most significant words. #
+# #
+# The most sig. longword of the 64 bit dividend must be in %d5, least #
+# in %d6. The divisor must be in the variable ddivisor, and the #
+# signed/unsigned flag ddusign must be set (0=unsigned,1=signed). #
+# The quotient is returned in %d6, remainder in %d5, unless the #
+# v (overflow) bit is set in the saved %ccr. If overflow, the dividend #
+# is unchanged. #
+#########################################################################
+dclassical:
+# if the divisor msw is 0, use simpler algorithm then the full blown
+# one at ddknuth:
+
+ cmpi.l %d7, &0xffff
+ bhi.b ddknuth # go use D. Knuth algorithm
+
+# Since the divisor is only a word (and larger than the mslw of the dividend),
+# a simpler algorithm may be used :
+# In the general case, four quotient words would be created by
+# dividing the divisor word into each dividend word. In this case,
+# the first two quotient words must be zero, or overflow would occur.
+# Since we already checked this case above, we can treat the most significant
+# longword of the dividend as (0) remainder (see Knuth) and merely complete
+# the last two divisions to get a quotient longword and word remainder:
+
+ clr.l %d1
+ swap %d5 # same as r*b if previous step rqd
+ swap %d6 # get u3 to lsw position
+ mov.w %d6, %d5 # rb + u3
+
+ divu.w %d7, %d5
+
+ mov.w %d5, %d1 # first quotient word
+ swap %d6 # get u4
+ mov.w %d6, %d5 # rb + u4
+
+ divu.w %d7, %d5
+
+ swap %d1
+ mov.w %d5, %d1 # 2nd quotient 'digit'
+ clr.w %d5
+ swap %d5 # now remainder
+ mov.l %d1, %d6 # and quotient
+
+ rts
+
+ddknuth:
+# In this algorithm, the divisor is treated as a 2 digit (word) number
+# which is divided into a 3 digit (word) dividend to get one quotient
+# digit (word). After subtraction, the dividend is shifted and the
+# process repeated. Before beginning, the divisor and quotient are
+# 'normalized' so that the process of estimating the quotient digit
+# will yield verifiably correct results..
+
+ clr.l DDNORMAL(%a6) # count of shifts for normalization
+ clr.b DDSECOND(%a6) # clear flag for quotient digits
+ clr.l %d1 # %d1 will hold trial quotient
+ddnchk:
+ btst &31, %d7 # must we normalize? first word of
+ bne.b ddnormalized # divisor (V1) must be >= 65536/2
+ addq.l &0x1, DDNORMAL(%a6) # count normalization shifts
+ lsl.l &0x1, %d7 # shift the divisor
+ lsl.l &0x1, %d6 # shift u4,u3 with overflow to u2
+ roxl.l &0x1, %d5 # shift u1,u2
+ bra.w ddnchk
+ddnormalized:
+
+# Now calculate an estimate of the quotient words (msw first, then lsw).
+# The comments use subscripts for the first quotient digit determination.
+ mov.l %d7, %d3 # divisor
+ mov.l %d5, %d2 # dividend mslw
+ swap %d2
+ swap %d3
+ cmp.w %d2, %d3 # V1 = U1 ?
+ bne.b ddqcalc1
+ mov.w &0xffff, %d1 # use max trial quotient word
+ bra.b ddadj0
+ddqcalc1:
+ mov.l %d5, %d1
+
+ divu.w %d3, %d1 # use quotient of mslw/msw
+
+ andi.l &0x0000ffff, %d1 # zero any remainder
+ddadj0:
+
+# now test the trial quotient and adjust. This step plus the
+# normalization assures (according to Knuth) that the trial
+# quotient will be at worst 1 too large.
+ mov.l %d6, -(%sp)
+ clr.w %d6 # word u3 left
+ swap %d6 # in lsw position
+ddadj1: mov.l %d7, %d3
+ mov.l %d1, %d2
+ mulu.w %d7, %d2 # V2q
+ swap %d3
+ mulu.w %d1, %d3 # V1q
+ mov.l %d5, %d4 # U1U2
+ sub.l %d3, %d4 # U1U2 - V1q
+
+ swap %d4
+
+ mov.w %d4,%d0
+ mov.w %d6,%d4 # insert lower word (U3)
+
+ tst.w %d0 # is upper word set?
+ bne.w ddadjd1
+
+# add.l %d6, %d4 # (U1U2 - V1q) + U3
+
+ cmp.l %d2, %d4
+ bls.b ddadjd1 # is V2q > (U1U2-V1q) + U3 ?
+ subq.l &0x1, %d1 # yes, decrement and recheck
+ bra.b ddadj1
+ddadjd1:
+# now test the word by multiplying it by the divisor (V1V2) and comparing
+# the 3 digit (word) result with the current dividend words
+ mov.l %d5, -(%sp) # save %d5 (%d6 already saved)
+ mov.l %d1, %d6
+ swap %d6 # shift answer to ms 3 words
+ mov.l %d7, %d5
+ bsr.l dmm2
+ mov.l %d5, %d2 # now %d2,%d3 are trial*divisor
+ mov.l %d6, %d3
+ mov.l (%sp)+, %d5 # restore dividend
+ mov.l (%sp)+, %d6
+ sub.l %d3, %d6
+ subx.l %d2, %d5 # subtract double precision
+ bcc dd2nd # no carry, do next quotient digit
+ subq.l &0x1, %d1 # q is one too large
+# need to add back divisor longword to current ms 3 digits of dividend
+# - according to Knuth, this is done only 2 out of 65536 times for random
+# divisor, dividend selection.
+ clr.l %d2
+ mov.l %d7, %d3
+ swap %d3
+ clr.w %d3 # %d3 now ls word of divisor
+ add.l %d3, %d6 # aligned with 3rd word of dividend
+ addx.l %d2, %d5
+ mov.l %d7, %d3
+ clr.w %d3 # %d3 now ms word of divisor
+ swap %d3 # aligned with 2nd word of dividend
+ add.l %d3, %d5
+dd2nd:
+ tst.b DDSECOND(%a6) # both q words done?
+ bne.b ddremain
+# first quotient digit now correct. store digit and shift the
+# (subtracted) dividend
+ mov.w %d1, DDQUOTIENT(%a6)
+ clr.l %d1
+ swap %d5
+ swap %d6
+ mov.w %d6, %d5
+ clr.w %d6
+ st DDSECOND(%a6) # second digit
+ bra.w ddnormalized
+ddremain:
+# add 2nd word to quotient, get the remainder.
+ mov.w %d1, DDQUOTIENT+2(%a6)
+# shift down one word/digit to renormalize remainder.
+ mov.w %d5, %d6
+ swap %d6
+ swap %d5
+ mov.l DDNORMAL(%a6), %d7 # get norm shift count
+ beq.b ddrn
+ subq.l &0x1, %d7 # set for loop count
+ddnlp:
+ lsr.l &0x1, %d5 # shift into %d6
+ roxr.l &0x1, %d6
+ dbf %d7, ddnlp
+ddrn:
+ mov.l %d6, %d5 # remainder
+ mov.l DDQUOTIENT(%a6), %d6 # quotient
+
+ rts
+dmm2:
+# factors for the 32X32->64 multiplication are in %d5 and %d6.
+# returns 64 bit result in %d5 (hi) %d6(lo).
+# destroys %d2,%d3,%d4.
+
+# multiply hi,lo words of each factor to get 4 intermediate products
+ mov.l %d6, %d2
+ mov.l %d6, %d3
+ mov.l %d5, %d4
+ swap %d3
+ swap %d4
+ mulu.w %d5, %d6 # %d6 <- lsw*lsw
+ mulu.w %d3, %d5 # %d5 <- msw-dest*lsw-source
+ mulu.w %d4, %d2 # %d2 <- msw-source*lsw-dest
+ mulu.w %d4, %d3 # %d3 <- msw*msw
+# now use swap and addx to consolidate to two longwords
+ clr.l %d4
+ swap %d6
+ add.w %d5, %d6 # add msw of l*l to lsw of m*l product
+ addx.w %d4, %d3 # add any carry to m*m product
+ add.w %d2, %d6 # add in lsw of other m*l product
+ addx.w %d4, %d3 # add any carry to m*m product
+ swap %d6 # %d6 is low 32 bits of final product
+ clr.w %d5
+ clr.w %d2 # lsw of two mixed products used,
+ swap %d5 # now use msws of longwords
+ swap %d2
+ add.l %d2, %d5
+ add.l %d3, %d5 # %d5 now ms 32 bits of final product
+ rts
+
+##########
+dcontrolmodel_s:
+ movq.l &LONG,%d0
+ bsr.l _calc_ea # calc <ea>
+
+ cmpi.b SPCOND_FLG(%a6),&immed_flg # immediate addressing mode?
+ beq.b dimmed # yes
+
+ mov.l %a0,%a2
+ bsr.l _dmem_read_long # fetch divisor from <ea>
+
+ tst.l %d1 # dfetch error?
+ bne.b div64_err # yes
+
+ mov.l %d0, %d7
+ bra.w dgotsrcl
+
+# we have to split out immediate data here because it must be read using
+# imem_read() instead of dmem_read(). this becomes especially important
+# if the fetch runs into some deadly fault.
+dimmed:
+ addq.l &0x4,EXC_EXTWPTR(%a6)
+ bsr.l _imem_read_long # read immediate value
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.l %d0,%d7
+ bra.w dgotsrcl
+
+##########
+
+# if dmem_read_long() returns a fail message in d1, the package
+# must create an access error frame. here, we pass a skeleton fslw
+# and the failing address to the routine that creates the new frame.
+# also, we call isp_restore in case the effective addressing mode was
+# (an)+ or -(an) in which case the previous "an" value must be restored.
+# FSLW:
+# read = true
+# size = longword
+# TM = data
+# software emulation error = true
+div64_err:
+ bsr.l isp_restore # restore addr reg
+ mov.l %a2,%a0 # pass failing address
+ mov.l &0x01010001,%d0 # pass fslw
+ bra.l isp_dacc
+
+#########################################################################
+# XDEF **************************************************************** #
+# _mul64(): routine to emulate mul{u,s}.l <ea>,Dh:Dl 32x32->64 #
+# #
+# XREF **************************************************************** #
+# _calc_ea() - calculate effective address #
+# isp_iacc() - handle instruction access error exception #
+# isp_dacc() - handle data access error exception #
+# isp_restore() - restore An on access error w/ -() or ()+ #
+# #
+# INPUT *************************************************************** #
+# none #
+# #
+# OUTPUT ************************************************************** #
+# If exiting through isp_dacc... #
+# a0 = failing address #
+# d0 = FSLW #
+# else #
+# none #
+# #
+# ALGORITHM *********************************************************** #
+# First, decode the operand location. If it's in Dn, fetch from #
+# the stack. If it's in memory, use _calc_ea() to calculate the #
+# effective address. Use _dmem_read_long() to fetch at that address. #
+# Unless the operand is immediate data. Then use _imem_read_long(). #
+# Send failures to isp_dacc() or isp_iacc() as appropriate. #
+# If the operands are signed, make them unsigned and save the #
+# sign info for later. Perform the multiplication using 16x16->32 #
+# unsigned multiplies and "add" instructions. Store the high and low #
+# portions of the result in the appropriate data registers on the #
+# stack. Calculate the condition codes, also. #
+# #
+#########################################################################
+
+#############
+# mul(u,s)l #
+#############
+ global _mul64
+_mul64:
+ mov.b EXC_OPWORD+1(%a6), %d0 # extract src {mode,reg}
+ cmpi.b %d0, &0x7 # is src mode Dn or other?
+ bgt.w mul64_memop # src is in memory
+
+# multiplier operand in the data register file.
+# must extract the register number and fetch the operand from the stack.
+mul64_regop:
+ andi.w &0x7, %d0 # extract Dn
+ mov.l (EXC_DREGS,%a6,%d0.w*4), %d3 # fetch multiplier
+
+# multiplier is in %d3. now, extract Dl and Dh fields and fetch the
+# multiplicand from the data register specified by Dl.
+mul64_multiplicand:
+ mov.w EXC_EXTWORD(%a6), %d2 # fetch ext word
+ clr.w %d1 # clear Dh reg
+ mov.b %d2, %d1 # grab Dh
+ rol.w &0x4, %d2 # align Dl byte
+ andi.w &0x7, %d2 # extract Dl
+
+ mov.l (EXC_DREGS,%a6,%d2.w*4), %d4 # get multiplicand
+
+# check for the case of "zero" result early
+ tst.l %d4 # test multiplicand
+ beq.w mul64_zero # handle zero separately
+ tst.l %d3 # test multiplier
+ beq.w mul64_zero # handle zero separately
+
+# multiplier is in %d3 and multiplicand is in %d4.
+# if the operation is to be signed, then the operands are converted
+# to unsigned and the result sign is saved for the end.
+ clr.b EXC_TEMP(%a6) # clear temp space
+ btst &0x3, EXC_EXTWORD(%a6) # signed or unsigned?
+ beq.b mul64_alg # unsigned; skip sgn calc
+
+ tst.l %d3 # is multiplier negative?
+ bge.b mul64_chk_md_sgn # no
+ neg.l %d3 # make multiplier positive
+ ori.b &0x1, EXC_TEMP(%a6) # save multiplier sgn
+
+# the result sign is the exclusive or of the operand sign bits.
+mul64_chk_md_sgn:
+ tst.l %d4 # is multiplicand negative?
+ bge.b mul64_alg # no
+ neg.l %d4 # make multiplicand positive
+ eori.b &0x1, EXC_TEMP(%a6) # calculate correct sign
+
+#########################################################################
+# 63 32 0 #
+# ---------------------------- #
+# | hi(mplier) * hi(mplicand)| #
+# ---------------------------- #
+# ----------------------------- #
+# | hi(mplier) * lo(mplicand) | #
+# ----------------------------- #
+# ----------------------------- #
+# | lo(mplier) * hi(mplicand) | #
+# ----------------------------- #
+# | ----------------------------- #
+# --|-- | lo(mplier) * lo(mplicand) | #
+# | ----------------------------- #
+# ======================================================== #
+# -------------------------------------------------------- #
+# | hi(result) | lo(result) | #
+# -------------------------------------------------------- #
+#########################################################################
+mul64_alg:
+# load temp registers with operands
+ mov.l %d3, %d5 # mr in %d5
+ mov.l %d3, %d6 # mr in %d6
+ mov.l %d4, %d7 # md in %d7
+ swap %d6 # hi(mr) in lo %d6
+ swap %d7 # hi(md) in lo %d7
+
+# complete necessary multiplies:
+ mulu.w %d4, %d3 # [1] lo(mr) * lo(md)
+ mulu.w %d6, %d4 # [2] hi(mr) * lo(md)
+ mulu.w %d7, %d5 # [3] lo(mr) * hi(md)
+ mulu.w %d7, %d6 # [4] hi(mr) * hi(md)
+
+# add lo portions of [2],[3] to hi portion of [1].
+# add carries produced from these adds to [4].
+# lo([1]) is the final lo 16 bits of the result.
+ clr.l %d7 # load %d7 w/ zero value
+ swap %d3 # hi([1]) <==> lo([1])
+ add.w %d4, %d3 # hi([1]) + lo([2])
+ addx.l %d7, %d6 # [4] + carry
+ add.w %d5, %d3 # hi([1]) + lo([3])
+ addx.l %d7, %d6 # [4] + carry
+ swap %d3 # lo([1]) <==> hi([1])
+
+# lo portions of [2],[3] have been added in to final result.
+# now, clear lo, put hi in lo reg, and add to [4]
+ clr.w %d4 # clear lo([2])
+ clr.w %d5 # clear hi([3])
+ swap %d4 # hi([2]) in lo %d4
+ swap %d5 # hi([3]) in lo %d5
+ add.l %d5, %d4 # [4] + hi([2])
+ add.l %d6, %d4 # [4] + hi([3])
+
+# unsigned result is now in {%d4,%d3}
+ tst.b EXC_TEMP(%a6) # should result be signed?
+ beq.b mul64_done # no
+
+# result should be a signed negative number.
+# compute 2's complement of the unsigned number:
+# -negate all bits and add 1
+mul64_neg:
+ not.l %d3 # negate lo(result) bits
+ not.l %d4 # negate hi(result) bits
+ addq.l &1, %d3 # add 1 to lo(result)
+ addx.l %d7, %d4 # add carry to hi(result)
+
+# the result is saved to the register file.
+# for '040 compatibility, if Dl == Dh then only the hi(result) is
+# saved. so, saving hi after lo accomplishes this without need to
+# check Dl,Dh equality.
+mul64_done:
+ mov.l %d3, (EXC_DREGS,%a6,%d2.w*4) # save lo(result)
+ mov.w &0x0, %cc
+ mov.l %d4, (EXC_DREGS,%a6,%d1.w*4) # save hi(result)
+
+# now, grab the condition codes. only one that can be set is 'N'.
+# 'N' CAN be set if the operation is unsigned if bit 63 is set.
+ mov.w %cc, %d7 # fetch %ccr to see if 'N' set
+ andi.b &0x8, %d7 # extract 'N' bit
+
+mul64_ccode_set:
+ mov.b EXC_CC+1(%a6), %d6 # fetch previous %ccr
+ andi.b &0x10, %d6 # all but 'X' bit changes
+
+ or.b %d7, %d6 # group 'X' and 'N'
+ mov.b %d6, EXC_CC+1(%a6) # save new %ccr
+
+ rts
+
+# one or both of the operands is zero so the result is also zero.
+# save the zero result to the register file and set the 'Z' ccode bit.
+mul64_zero:
+ clr.l (EXC_DREGS,%a6,%d2.w*4) # save lo(result)
+ clr.l (EXC_DREGS,%a6,%d1.w*4) # save hi(result)
+
+ movq.l &0x4, %d7 # set 'Z' ccode bit
+ bra.b mul64_ccode_set # finish ccode set
+
+##########
+
+# multiplier operand is in memory at the effective address.
+# must calculate the <ea> and go fetch the 32-bit operand.
+mul64_memop:
+ movq.l &LONG, %d0 # pass # of bytes
+ bsr.l _calc_ea # calculate <ea>
+
+ cmpi.b SPCOND_FLG(%a6),&immed_flg # immediate addressing mode?
+ beq.b mul64_immed # yes
+
+ mov.l %a0,%a2
+ bsr.l _dmem_read_long # fetch src from addr (%a0)
+
+ tst.l %d1 # dfetch error?
+ bne.w mul64_err # yes
+
+ mov.l %d0, %d3 # store multiplier in %d3
+
+ bra.w mul64_multiplicand
+
+# we have to split out immediate data here because it must be read using
+# imem_read() instead of dmem_read(). this becomes especially important
+# if the fetch runs into some deadly fault.
+mul64_immed:
+ addq.l &0x4,EXC_EXTWPTR(%a6)
+ bsr.l _imem_read_long # read immediate value
+
+ tst.l %d1 # ifetch error?
+ bne.l isp_iacc # yes
+
+ mov.l %d0,%d3
+ bra.w mul64_multiplicand
+
+##########
+
+# if dmem_read_long() returns a fail message in d1, the package
+# must create an access error frame. here, we pass a skeleton fslw
+# and the failing address to the routine that creates the new frame.
+# also, we call isp_restore in case the effective addressing mode was
+# (an)+ or -(an) in which case the previous "an" value must be restored.
+# FSLW:
+# read = true
+# size = longword
+# TM = data
+# software emulation error = true
+mul64_err:
+ bsr.l isp_restore # restore addr reg
+ mov.l %a2,%a0 # pass failing address
+ mov.l &0x01010001,%d0 # pass fslw
+ bra.l isp_dacc
+
+#########################################################################
+# XDEF **************************************************************** #
+# _compandset2(): routine to emulate cas2() #
+# (internal to package) #
+# #
+# _isp_cas2_finish(): store ccodes, store compare regs #
+# (external to package) #
+# #
+# XREF **************************************************************** #
+# _real_lock_page() - "callout" to lock op's page from page-outs #
+# _cas_terminate2() - access error exit #
+# _real_cas2() - "callout" to core cas2 emulation code #
+# _real_unlock_page() - "callout" to unlock page #
+# #
+# INPUT *************************************************************** #
+# _compandset2(): #
+# d0 = instruction extension word #
+# #
+# _isp_cas2_finish(): #
+# see cas2 core emulation code #
+# #
+# OUTPUT ************************************************************** #
+# _compandset2(): #
+# see cas2 core emulation code #
+# #
+# _isp_cas_finish(): #
+# None (register file or memroy changed as appropriate) #
+# #
+# ALGORITHM *********************************************************** #
+# compandset2(): #
+# Decode the instruction and fetch the appropriate Update and #
+# Compare operands. Then call the "callout" _real_lock_page() for each #
+# memory operand address so that the operating system can keep these #
+# pages from being paged out. If either _real_lock_page() fails, exit #
+# through _cas_terminate2(). Don't forget to unlock the 1st locked page #
+# using _real_unlock_paged() if the 2nd lock-page fails. #
+# Finally, branch to the core cas2 emulation code by calling the #
+# "callout" _real_cas2(). #
+# #
+# _isp_cas2_finish(): #
+# Re-perform the comparison so we can determine the condition #
+# codes which were too much trouble to keep around during the locked #
+# emulation. Then unlock each operands page by calling the "callout" #
+# _real_unlock_page(). #
+# #
+#########################################################################
+
+set ADDR1, EXC_TEMP+0xc
+set ADDR2, EXC_TEMP+0x0
+set DC2, EXC_TEMP+0xa
+set DC1, EXC_TEMP+0x8
+
+ global _compandset2
+_compandset2:
+ mov.l %d0,EXC_TEMP+0x4(%a6) # store for possible restart
+ mov.l %d0,%d1 # extension word in d0
+
+ rol.w &0x4,%d0
+ andi.w &0xf,%d0 # extract Rn2
+ mov.l (EXC_DREGS,%a6,%d0.w*4),%a1 # fetch ADDR2
+ mov.l %a1,ADDR2(%a6)
+
+ mov.l %d1,%d0
+
+ lsr.w &0x6,%d1
+ andi.w &0x7,%d1 # extract Du2
+ mov.l (EXC_DREGS,%a6,%d1.w*4),%d5 # fetch Update2 Op
+
+ andi.w &0x7,%d0 # extract Dc2
+ mov.l (EXC_DREGS,%a6,%d0.w*4),%d3 # fetch Compare2 Op
+ mov.w %d0,DC2(%a6)
+
+ mov.w EXC_EXTWORD(%a6),%d0
+ mov.l %d0,%d1
+
+ rol.w &0x4,%d0
+ andi.w &0xf,%d0 # extract Rn1
+ mov.l (EXC_DREGS,%a6,%d0.w*4),%a0 # fetch ADDR1
+ mov.l %a0,ADDR1(%a6)
+
+ mov.l %d1,%d0
+
+ lsr.w &0x6,%d1
+ andi.w &0x7,%d1 # extract Du1
+ mov.l (EXC_DREGS,%a6,%d1.w*4),%d4 # fetch Update1 Op
+
+ andi.w &0x7,%d0 # extract Dc1
+ mov.l (EXC_DREGS,%a6,%d0.w*4),%d2 # fetch Compare1 Op
+ mov.w %d0,DC1(%a6)
+
+ btst &0x1,EXC_OPWORD(%a6) # word or long?
+ sne %d7
+
+ btst &0x5,EXC_ISR(%a6) # user or supervisor?
+ sne %d6
+
+ mov.l %a0,%a2
+ mov.l %a1,%a3
+
+ mov.l %d7,%d1 # pass size
+ mov.l %d6,%d0 # pass mode
+ bsr.l _real_lock_page # lock page
+ mov.l %a2,%a0
+ tst.l %d0 # error?
+ bne.l _cas_terminate2 # yes
+
+ mov.l %d7,%d1 # pass size
+ mov.l %d6,%d0 # pass mode
+ mov.l %a3,%a0 # pass addr
+ bsr.l _real_lock_page # lock page
+ mov.l %a3,%a0
+ tst.l %d0 # error?
+ bne.b cas_preterm # yes
+
+ mov.l %a2,%a0
+ mov.l %a3,%a1
+
+ bra.l _real_cas2
+
+# if the 2nd lock attempt fails, then we must still unlock the
+# first page(s).
+cas_preterm:
+ mov.l %d0,-(%sp) # save FSLW
+ mov.l %d7,%d1 # pass size
+ mov.l %d6,%d0 # pass mode
+ mov.l %a2,%a0 # pass ADDR1
+ bsr.l _real_unlock_page # unlock first page(s)
+ mov.l (%sp)+,%d0 # restore FSLW
+ mov.l %a3,%a0 # pass failing addr
+ bra.l _cas_terminate2
+
+#############################################################
+
+ global _isp_cas2_finish
+_isp_cas2_finish:
+ btst &0x1,EXC_OPWORD(%a6)
+ bne.b cas2_finish_l
+
+ mov.w EXC_CC(%a6),%cc # load old ccodes
+ cmp.w %d0,%d2
+ bne.b cas2_finish_w_save
+ cmp.w %d1,%d3
+cas2_finish_w_save:
+ mov.w %cc,EXC_CC(%a6) # save new ccodes
+
+ tst.b %d4 # update compare reg?
+ bne.b cas2_finish_w_done # no
+
+ mov.w DC2(%a6),%d3 # fetch Dc2
+ mov.w %d1,(2+EXC_DREGS,%a6,%d3.w*4) # store new Compare2 Op
+
+ mov.w DC1(%a6),%d2 # fetch Dc1
+ mov.w %d0,(2+EXC_DREGS,%a6,%d2.w*4) # store new Compare1 Op
+
+cas2_finish_w_done:
+ btst &0x5,EXC_ISR(%a6)
+ sne %d2
+ mov.l %d2,%d0 # pass mode
+ sf %d1 # pass size
+ mov.l ADDR1(%a6),%a0 # pass ADDR1
+ bsr.l _real_unlock_page # unlock page
+
+ mov.l %d2,%d0 # pass mode
+ sf %d1 # pass size
+ mov.l ADDR2(%a6),%a0 # pass ADDR2
+ bsr.l _real_unlock_page # unlock page
+ rts
+
+cas2_finish_l:
+ mov.w EXC_CC(%a6),%cc # load old ccodes
+ cmp.l %d0,%d2
+ bne.b cas2_finish_l_save
+ cmp.l %d1,%d3
+cas2_finish_l_save:
+ mov.w %cc,EXC_CC(%a6) # save new ccodes
+
+ tst.b %d4 # update compare reg?
+ bne.b cas2_finish_l_done # no
+
+ mov.w DC2(%a6),%d3 # fetch Dc2
+ mov.l %d1,(EXC_DREGS,%a6,%d3.w*4) # store new Compare2 Op
+
+ mov.w DC1(%a6),%d2 # fetch Dc1
+ mov.l %d0,(EXC_DREGS,%a6,%d2.w*4) # store new Compare1 Op
+
+cas2_finish_l_done:
+ btst &0x5,EXC_ISR(%a6)
+ sne %d2
+ mov.l %d2,%d0 # pass mode
+ st %d1 # pass size
+ mov.l ADDR1(%a6),%a0 # pass ADDR1
+ bsr.l _real_unlock_page # unlock page
+
+ mov.l %d2,%d0 # pass mode
+ st %d1 # pass size
+ mov.l ADDR2(%a6),%a0 # pass ADDR2
+ bsr.l _real_unlock_page # unlock page
+ rts
+
+########
+ global cr_cas2
+cr_cas2:
+ mov.l EXC_TEMP+0x4(%a6),%d0
+ bra.w _compandset2
+
+#########################################################################
+# XDEF **************************************************************** #
+# _compandset(): routine to emulate cas w/ misaligned <ea> #
+# (internal to package) #
+# _isp_cas_finish(): routine called when cas emulation completes #
+# (external and internal to package) #
+# _isp_cas_restart(): restart cas emulation after a fault #
+# (external to package) #
+# _isp_cas_terminate(): create access error stack frame on fault #
+# (external and internal to package) #
+# _isp_cas_inrange(): checks whether instr addess is within range #
+# of core cas/cas2emulation code #
+# (external to package) #
+# #
+# XREF **************************************************************** #
+# _calc_ea(): calculate effective address #
+# #
+# INPUT *************************************************************** #
+# compandset(): #
+# none #
+# _isp_cas_restart(): #
+# d6 = previous sfc/dfc #
+# _isp_cas_finish(): #
+# _isp_cas_terminate(): #
+# a0 = failing address #
+# d0 = FSLW #
+# d6 = previous sfc/dfc #
+# _isp_cas_inrange(): #
+# a0 = instruction address to be checked #
+# #
+# OUTPUT ************************************************************** #
+# compandset(): #
+# none #
+# _isp_cas_restart(): #
+# a0 = effective address #
+# d7 = word or longword flag #
+# _isp_cas_finish(): #
+# a0 = effective address #
+# _isp_cas_terminate(): #
+# initial register set before emulation exception #
+# _isp_cas_inrange(): #
+# d0 = 0 => in range; -1 => out of range #
+# #
+# ALGORITHM *********************************************************** #
+# #
+# compandset(): #
+# First, calculate the effective address. Then, decode the #
+# instruction word and fetch the "compare" (DC) and "update" (Du) #
+# operands. #
+# Next, call the external routine _real_lock_page() so that the #
+# operating system can keep this page from being paged out while we're #
+# in this routine. If this call fails, jump to _cas_terminate2(). #
+# The routine then branches to _real_cas(). This external routine #
+# that actually emulates cas can be supplied by the external os or #
+# made to point directly back into the 060ISP which has a routine for #
+# this purpose. #
+# #
+# _isp_cas_finish(): #
+# Either way, after emulation, the package is re-entered at #
+# _isp_cas_finish(). This routine re-compares the operands in order to #
+# set the condition codes. Finally, these routines will call #
+# _real_unlock_page() in order to unlock the pages that were previously #
+# locked. #
+# #
+# _isp_cas_restart(): #
+# This routine can be entered from an access error handler where #
+# the emulation sequence should be re-started from the beginning. #
+# #
+# _isp_cas_terminate(): #
+# This routine can be entered from an access error handler where #
+# an emulation operand access failed and the operating system would #
+# like an access error stack frame created instead of the current #
+# unimplemented integer instruction frame. #
+# Also, the package enters here if a call to _real_lock_page() #
+# fails. #
+# #
+# _isp_cas_inrange(): #
+# Checks to see whether the instruction address passed to it in #
+# a0 is within the software package cas/cas2 emulation routines. This #
+# can be helpful for an operating system to determine whether an access #
+# error during emulation was due to a cas/cas2 emulation access. #
+# #
+#########################################################################
+
+set DC, EXC_TEMP+0x8
+set ADDR, EXC_TEMP+0x4
+
+ global _compandset
+_compandset:
+ btst &0x1,EXC_OPWORD(%a6) # word or long operation?
+ bne.b compandsetl # long
+
+compandsetw:
+ movq.l &0x2,%d0 # size = 2 bytes
+ bsr.l _calc_ea # a0 = calculated <ea>
+ mov.l %a0,ADDR(%a6) # save <ea> for possible restart
+ sf %d7 # clear d7 for word size
+ bra.b compandsetfetch
+
+compandsetl:
+ movq.l &0x4,%d0 # size = 4 bytes
+ bsr.l _calc_ea # a0 = calculated <ea>
+ mov.l %a0,ADDR(%a6) # save <ea> for possible restart
+ st %d7 # set d7 for longword size
+
+compandsetfetch:
+ mov.w EXC_EXTWORD(%a6),%d0 # fetch cas extension word
+ mov.l %d0,%d1 # make a copy
+
+ lsr.w &0x6,%d0
+ andi.w &0x7,%d0 # extract Du
+ mov.l (EXC_DREGS,%a6,%d0.w*4),%d2 # get update operand
+
+ andi.w &0x7,%d1 # extract Dc
+ mov.l (EXC_DREGS,%a6,%d1.w*4),%d4 # get compare operand
+ mov.w %d1,DC(%a6) # save Dc
+
+ btst &0x5,EXC_ISR(%a6) # which mode for exception?
+ sne %d6 # set on supervisor mode
+
+ mov.l %a0,%a2 # save temporarily
+ mov.l %d7,%d1 # pass size
+ mov.l %d6,%d0 # pass mode
+ bsr.l _real_lock_page # lock page
+ tst.l %d0 # did error occur?
+ bne.w _cas_terminate2 # yes, clean up the mess
+ mov.l %a2,%a0 # pass addr in a0
+
+ bra.l _real_cas
+
+########
+ global _isp_cas_finish
+_isp_cas_finish:
+ btst &0x1,EXC_OPWORD(%a6)
+ bne.b cas_finish_l
+
+# just do the compare again since it's faster than saving the ccodes
+# from the locked routine...
+cas_finish_w:
+ mov.w EXC_CC(%a6),%cc # restore cc
+ cmp.w %d0,%d4 # do word compare
+ mov.w %cc,EXC_CC(%a6) # save cc
+
+ tst.b %d1 # update compare reg?
+ bne.b cas_finish_w_done # no
+
+ mov.w DC(%a6),%d3
+ mov.w %d0,(EXC_DREGS+2,%a6,%d3.w*4) # Dc = destination
+
+cas_finish_w_done:
+ mov.l ADDR(%a6),%a0 # pass addr
+ sf %d1 # pass size
+ btst &0x5,EXC_ISR(%a6)
+ sne %d0 # pass mode
+ bsr.l _real_unlock_page # unlock page
+ rts
+
+# just do the compare again since it's faster than saving the ccodes
+# from the locked routine...
+cas_finish_l:
+ mov.w EXC_CC(%a6),%cc # restore cc
+ cmp.l %d0,%d4 # do longword compare
+ mov.w %cc,EXC_CC(%a6) # save cc
+
+ tst.b %d1 # update compare reg?
+ bne.b cas_finish_l_done # no
+
+ mov.w DC(%a6),%d3
+ mov.l %d0,(EXC_DREGS,%a6,%d3.w*4) # Dc = destination
+
+cas_finish_l_done:
+ mov.l ADDR(%a6),%a0 # pass addr
+ st %d1 # pass size
+ btst &0x5,EXC_ISR(%a6)
+ sne %d0 # pass mode
+ bsr.l _real_unlock_page # unlock page
+ rts
+
+########
+
+ global _isp_cas_restart
+_isp_cas_restart:
+ mov.l %d6,%sfc # restore previous sfc
+ mov.l %d6,%dfc # restore previous dfc
+
+ cmpi.b EXC_OPWORD+1(%a6),&0xfc # cas or cas2?
+ beq.l cr_cas2 # cas2
+cr_cas:
+ mov.l ADDR(%a6),%a0 # load <ea>
+ btst &0x1,EXC_OPWORD(%a6) # word or long operation?
+ sne %d7 # set d7 accordingly
+ bra.w compandsetfetch
+
+########
+
+# At this stage, it would be nice if d0 held the FSLW.
+ global _isp_cas_terminate
+_isp_cas_terminate:
+ mov.l %d6,%sfc # restore previous sfc
+ mov.l %d6,%dfc # restore previous dfc
+
+ global _cas_terminate2
+_cas_terminate2:
+ mov.l %a0,%a2 # copy failing addr to a2
+
+ mov.l %d0,-(%sp)
+ bsr.l isp_restore # restore An (if ()+ or -())
+ mov.l (%sp)+,%d0
+
+ addq.l &0x4,%sp # remove sub return addr
+ subq.l &0x8,%sp # make room for bigger stack
+ subq.l &0x8,%a6 # shift frame ptr down, too
+ mov.l &26,%d1 # want to move 51 longwords
+ lea 0x8(%sp),%a0 # get address of old stack
+ lea 0x0(%sp),%a1 # get address of new stack
+cas_term_cont:
+ mov.l (%a0)+,(%a1)+ # move a longword
+ dbra.w %d1,cas_term_cont # keep going
+
+ mov.w &0x4008,EXC_IVOFF(%a6) # put new stk fmt, voff
+ mov.l %a2,EXC_IVOFF+0x2(%a6) # put faulting addr on stack
+ mov.l %d0,EXC_IVOFF+0x6(%a6) # put FSLW on stack
+ movm.l EXC_DREGS(%a6),&0x3fff # restore user regs
+ unlk %a6 # unlink stack frame
+ bra.l _real_access
+
+########
+
+ global _isp_cas_inrange
+_isp_cas_inrange:
+ clr.l %d0 # clear return result
+ lea _CASHI(%pc),%a1 # load end of CAS core code
+ cmp.l %a1,%a0 # is PC in range?
+ blt.b cin_no # no
+ lea _CASLO(%pc),%a1 # load begin of CAS core code
+ cmp.l %a0,%a1 # is PC in range?
+ blt.b cin_no # no
+ rts # yes; return d0 = 0
+cin_no:
+ mov.l &-0x1,%d0 # out of range; return d0 = -1
+ rts
+
+#################################################################
+#################################################################
+#################################################################
+# This is the start of the cas and cas2 "core" emulation code. #
+# This is the section that may need to be replaced by the host #
+# OS if it is too operating system-specific. #
+# Please refer to the package documentation to see how to #
+# "replace" this section, if necessary. #
+#################################################################
+#################################################################
+#################################################################
+
+# ###### ## ###### ####
+# # # # # # #
+# # ###### ###### #
+# # # # # #
+# ###### # # ###### ######
+
+#########################################################################
+# XDEF **************************************************************** #
+# _isp_cas2(): "core" emulation code for the cas2 instruction #
+# #
+# XREF **************************************************************** #
+# _isp_cas2_finish() - only exit point for this emulation code; #
+# do clean-up; calculate ccodes; store #
+# Compare Ops if appropriate. #
+# #
+# INPUT *************************************************************** #
+# *see chart below* #
+# #
+# OUTPUT ************************************************************** #
+# *see chart below* #
+# #
+# ALGORITHM *********************************************************** #
+# (1) Make several copies of the effective address. #
+# (2) Save current SR; Then mask off all maskable interrupts. #
+# (3) Save current SFC/DFC (ASSUMED TO BE EQUAL!!!); Then set #
+# according to whether exception occurred in user or #
+# supervisor mode. #
+# (4) Use "plpaw" instruction to pre-load ATC with effective #
+# address pages(s). THIS SHOULD NOT FAULT!!! The relevant #
+# page(s) should have already been made resident prior to #
+# entering this routine. #
+# (5) Push the operand lines from the cache w/ "cpushl". #
+# In the 68040, this was done within the locked region. In #
+# the 68060, it is done outside of the locked region. #
+# (6) Use "plpar" instruction to do a re-load of ATC entries for #
+# ADDR1 since ADDR2 entries may have pushed ADDR1 out of the #
+# ATC. #
+# (7) Pre-fetch the core emulation instructions by executing #
+# one branch within each physical line (16 bytes) of the code #
+# before actually executing the code. #
+# (8) Load the BUSCR w/ the bus lock value. #
+# (9) Fetch the source operands using "moves". #
+# (10)Do the compares. If both equal, go to step (13). #
+# (11)Unequal. No update occurs. But, we do write the DST1 op #
+# back to itself (as w/ the '040) so we can gracefully unlock #
+# the bus (and assert LOCKE*) using BUSCR and the final move. #
+# (12)Exit. #
+# (13)Write update operand to the DST locations. Use BUSCR to #
+# assert LOCKE* for the final write operation. #
+# (14)Exit. #
+# #
+# The algorithm is actually implemented slightly differently #
+# depending on the size of the operation and the misalignment of the #
+# operands. A misaligned operand must be written in aligned chunks or #
+# else the BUSCR register control gets confused. #
+# #
+#########################################################################
+
+#################################################################
+# THIS IS THE STATE OF THE INTEGER REGISTER FILE UPON #
+# ENTERING _isp_cas2(). #
+# #
+# D0 = xxxxxxxx #
+# D1 = xxxxxxxx #
+# D2 = cmp operand 1 #
+# D3 = cmp operand 2 #
+# D4 = update oper 1 #
+# D5 = update oper 2 #
+# D6 = 'xxxxxxff if supervisor mode; 'xxxxxx00 if user mode #
+# D7 = 'xxxxxxff if longword operation; 'xxxxxx00 if word #
+# A0 = ADDR1 #
+# A1 = ADDR2 #
+# A2 = xxxxxxxx #
+# A3 = xxxxxxxx #
+# A4 = xxxxxxxx #
+# A5 = xxxxxxxx #
+# A6 = frame pointer #
+# A7 = stack pointer #
+#################################################################
+
+# align 0x1000
+# beginning label used by _isp_cas_inrange()
+ global _CASLO
+_CASLO:
+
+ global _isp_cas2
+_isp_cas2:
+ tst.b %d6 # user or supervisor mode?
+ bne.b cas2_supervisor # supervisor
+cas2_user:
+ movq.l &0x1,%d0 # load user data fc
+ bra.b cas2_cont
+cas2_supervisor:
+ movq.l &0x5,%d0 # load supervisor data fc
+cas2_cont:
+ tst.b %d7 # word or longword?
+ beq.w cas2w # word
+
+####
+cas2l:
+ mov.l %a0,%a2 # copy ADDR1
+ mov.l %a1,%a3 # copy ADDR2
+ mov.l %a0,%a4 # copy ADDR1
+ mov.l %a1,%a5 # copy ADDR2
+
+ addq.l &0x3,%a4 # ADDR1+3
+ addq.l &0x3,%a5 # ADDR2+3
+ mov.l %a2,%d1 # ADDR1
+
+# mask interrupts levels 0-6. save old mask value.
+ mov.w %sr,%d7 # save current SR
+ ori.w &0x0700,%sr # inhibit interrupts
+
+# load the SFC and DFC with the appropriate mode.
+ movc %sfc,%d6 # save old SFC/DFC
+ movc %d0,%sfc # store new SFC
+ movc %d0,%dfc # store new DFC
+
+# pre-load the operand ATC. no page faults should occur here because
+# _real_lock_page() should have taken care of this.
+ plpaw (%a2) # load atc for ADDR1
+ plpaw (%a4) # load atc for ADDR1+3
+ plpaw (%a3) # load atc for ADDR2
+ plpaw (%a5) # load atc for ADDR2+3
+
+# push the operand lines from the cache if they exist.
+ cpushl %dc,(%a2) # push line for ADDR1
+ cpushl %dc,(%a4) # push line for ADDR1+3
+ cpushl %dc,(%a3) # push line for ADDR2
+ cpushl %dc,(%a5) # push line for ADDR2+2
+
+ mov.l %d1,%a2 # ADDR1
+ addq.l &0x3,%d1
+ mov.l %d1,%a4 # ADDR1+3
+# if ADDR1 was ATC resident before the above "plpaw" and was executed
+# and it was the next entry scheduled for replacement and ADDR2
+# shares the same set, then the "plpaw" for ADDR2 can push the ADDR1
+# entries from the ATC. so, we do a second set of "plpa"s.
+ plpar (%a2) # load atc for ADDR1
+ plpar (%a4) # load atc for ADDR1+3
+
+# load the BUSCR values.
+ mov.l &0x80000000,%a2 # assert LOCK* buscr value
+ mov.l &0xa0000000,%a3 # assert LOCKE* buscr value
+ mov.l &0x00000000,%a4 # buscr unlock value
+
+# there are three possible mis-aligned cases for longword cas. they
+# are separated because the final write which asserts LOCKE* must
+# be aligned.
+ mov.l %a0,%d0 # is ADDR1 misaligned?
+ andi.b &0x3,%d0
+ beq.b CAS2L_ENTER # no
+ cmpi.b %d0,&0x2
+ beq.w CAS2L2_ENTER # yes; word misaligned
+ bra.w CAS2L3_ENTER # yes; byte misaligned
+
+#
+# D0 = dst operand 1 <-
+# D1 = dst operand 2 <-
+# D2 = cmp operand 1
+# D3 = cmp operand 2
+# D4 = update oper 1
+# D5 = update oper 2
+# D6 = old SFC/DFC
+# D7 = old SR
+# A0 = ADDR1
+# A1 = ADDR2
+# A2 = bus LOCK* value
+# A3 = bus LOCKE* value
+# A4 = bus unlock value
+# A5 = xxxxxxxx
+#
+ align 0x10
+CAS2L_START:
+ movc %a2,%buscr # assert LOCK*
+ movs.l (%a1),%d1 # fetch Dest2[31:0]
+ movs.l (%a0),%d0 # fetch Dest1[31:0]
+ bra.b CAS2L_CONT
+CAS2L_ENTER:
+ bra.b ~+16
+
+CAS2L_CONT:
+ cmp.l %d0,%d2 # Dest1 - Compare1
+ bne.b CAS2L_NOUPDATE
+ cmp.l %d1,%d3 # Dest2 - Compare2
+ bne.b CAS2L_NOUPDATE
+ movs.l %d5,(%a1) # Update2[31:0] -> DEST2
+ bra.b CAS2L_UPDATE
+ bra.b ~+16
+
+CAS2L_UPDATE:
+ movc %a3,%buscr # assert LOCKE*
+ movs.l %d4,(%a0) # Update1[31:0] -> DEST1
+ movc %a4,%buscr # unlock the bus
+ bra.b cas2l_update_done
+ bra.b ~+16
+
+CAS2L_NOUPDATE:
+ movc %a3,%buscr # assert LOCKE*
+ movs.l %d0,(%a0) # Dest1[31:0] -> DEST1
+ movc %a4,%buscr # unlock the bus
+ bra.b cas2l_noupdate_done
+ bra.b ~+16
+
+CAS2L_FILLER:
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ bra.b CAS2L_START
+
+####
+
+#################################################################
+# THIS MUST BE THE STATE OF THE INTEGER REGISTER FILE UPON #
+# ENTERING _isp_cas2(). #
+# #
+# D0 = destination[31:0] operand 1 #
+# D1 = destination[31:0] operand 2 #
+# D2 = cmp[31:0] operand 1 #
+# D3 = cmp[31:0] operand 2 #
+# D4 = 'xxxxxx11 -> no reg update; 'xxxxxx00 -> update required #
+# D5 = xxxxxxxx #
+# D6 = xxxxxxxx #
+# D7 = xxxxxxxx #
+# A0 = xxxxxxxx #
+# A1 = xxxxxxxx #
+# A2 = xxxxxxxx #
+# A3 = xxxxxxxx #
+# A4 = xxxxxxxx #
+# A5 = xxxxxxxx #
+# A6 = frame pointer #
+# A7 = stack pointer #
+#################################################################
+
+cas2l_noupdate_done:
+
+# restore previous SFC/DFC value.
+ movc %d6,%sfc # restore old SFC
+ movc %d6,%dfc # restore old DFC
+
+# restore previous interrupt mask level.
+ mov.w %d7,%sr # restore old SR
+
+ sf %d4 # indicate no update was done
+ bra.l _isp_cas2_finish
+
+cas2l_update_done:
+
+# restore previous SFC/DFC value.
+ movc %d6,%sfc # restore old SFC
+ movc %d6,%dfc # restore old DFC
+
+# restore previous interrupt mask level.
+ mov.w %d7,%sr # restore old SR
+
+ st %d4 # indicate update was done
+ bra.l _isp_cas2_finish
+####
+
+ align 0x10
+CAS2L2_START:
+ movc %a2,%buscr # assert LOCK*
+ movs.l (%a1),%d1 # fetch Dest2[31:0]
+ movs.l (%a0),%d0 # fetch Dest1[31:0]
+ bra.b CAS2L2_CONT
+CAS2L2_ENTER:
+ bra.b ~+16
+
+CAS2L2_CONT:
+ cmp.l %d0,%d2 # Dest1 - Compare1
+ bne.b CAS2L2_NOUPDATE
+ cmp.l %d1,%d3 # Dest2 - Compare2
+ bne.b CAS2L2_NOUPDATE
+ movs.l %d5,(%a1) # Update2[31:0] -> Dest2
+ bra.b CAS2L2_UPDATE
+ bra.b ~+16
+
+CAS2L2_UPDATE:
+ swap %d4 # get Update1[31:16]
+ movs.w %d4,(%a0)+ # Update1[31:16] -> DEST1
+ movc %a3,%buscr # assert LOCKE*
+ swap %d4 # get Update1[15:0]
+ bra.b CAS2L2_UPDATE2
+ bra.b ~+16
+
+CAS2L2_UPDATE2:
+ movs.w %d4,(%a0) # Update1[15:0] -> DEST1+0x2
+ movc %a4,%buscr # unlock the bus
+ bra.w cas2l_update_done
+ nop
+ bra.b ~+16
+
+CAS2L2_NOUPDATE:
+ swap %d0 # get Dest1[31:16]
+ movs.w %d0,(%a0)+ # Dest1[31:16] -> DEST1
+ movc %a3,%buscr # assert LOCKE*
+ swap %d0 # get Dest1[15:0]
+ bra.b CAS2L2_NOUPDATE2
+ bra.b ~+16
+
+CAS2L2_NOUPDATE2:
+ movs.w %d0,(%a0) # Dest1[15:0] -> DEST1+0x2
+ movc %a4,%buscr # unlock the bus
+ bra.w cas2l_noupdate_done
+ nop
+ bra.b ~+16
+
+CAS2L2_FILLER:
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ bra.b CAS2L2_START
+
+#################################
+
+ align 0x10
+CAS2L3_START:
+ movc %a2,%buscr # assert LOCK*
+ movs.l (%a1),%d1 # fetch Dest2[31:0]
+ movs.l (%a0),%d0 # fetch Dest1[31:0]
+ bra.b CAS2L3_CONT
+CAS2L3_ENTER:
+ bra.b ~+16
+
+CAS2L3_CONT:
+ cmp.l %d0,%d2 # Dest1 - Compare1
+ bne.b CAS2L3_NOUPDATE
+ cmp.l %d1,%d3 # Dest2 - Compare2
+ bne.b CAS2L3_NOUPDATE
+ movs.l %d5,(%a1) # Update2[31:0] -> DEST2
+ bra.b CAS2L3_UPDATE
+ bra.b ~+16
+
+CAS2L3_UPDATE:
+ rol.l &0x8,%d4 # get Update1[31:24]
+ movs.b %d4,(%a0)+ # Update1[31:24] -> DEST1
+ swap %d4 # get Update1[23:8]
+ movs.w %d4,(%a0)+ # Update1[23:8] -> DEST1+0x1
+ bra.b CAS2L3_UPDATE2
+ bra.b ~+16
+
+CAS2L3_UPDATE2:
+ rol.l &0x8,%d4 # get Update1[7:0]
+ movc %a3,%buscr # assert LOCKE*
+ movs.b %d4,(%a0) # Update1[7:0] -> DEST1+0x3
+ bra.b CAS2L3_UPDATE3
+ nop
+ bra.b ~+16
+
+CAS2L3_UPDATE3:
+ movc %a4,%buscr # unlock the bus
+ bra.w cas2l_update_done
+ nop
+ nop
+ nop
+ bra.b ~+16
+
+CAS2L3_NOUPDATE:
+ rol.l &0x8,%d0 # get Dest1[31:24]
+ movs.b %d0,(%a0)+ # Dest1[31:24] -> DEST1
+ swap %d0 # get Dest1[23:8]
+ movs.w %d0,(%a0)+ # Dest1[23:8] -> DEST1+0x1
+ bra.b CAS2L3_NOUPDATE2
+ bra.b ~+16
+
+CAS2L3_NOUPDATE2:
+ rol.l &0x8,%d0 # get Dest1[7:0]
+ movc %a3,%buscr # assert LOCKE*
+ movs.b %d0,(%a0) # Update1[7:0] -> DEST1+0x3
+ bra.b CAS2L3_NOUPDATE3
+ nop
+ bra.b ~+16
+
+CAS2L3_NOUPDATE3:
+ movc %a4,%buscr # unlock the bus
+ bra.w cas2l_noupdate_done
+ nop
+ nop
+ nop
+ bra.b ~+14
+
+CAS2L3_FILLER:
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ bra.w CAS2L3_START
+
+#############################################################
+#############################################################
+
+cas2w:
+ mov.l %a0,%a2 # copy ADDR1
+ mov.l %a1,%a3 # copy ADDR2
+ mov.l %a0,%a4 # copy ADDR1
+ mov.l %a1,%a5 # copy ADDR2
+
+ addq.l &0x1,%a4 # ADDR1+1
+ addq.l &0x1,%a5 # ADDR2+1
+ mov.l %a2,%d1 # ADDR1
+
+# mask interrupt levels 0-6. save old mask value.
+ mov.w %sr,%d7 # save current SR
+ ori.w &0x0700,%sr # inhibit interrupts
+
+# load the SFC and DFC with the appropriate mode.
+ movc %sfc,%d6 # save old SFC/DFC
+ movc %d0,%sfc # store new SFC
+ movc %d0,%dfc # store new DFC
+
+# pre-load the operand ATC. no page faults should occur because
+# _real_lock_page() should have taken care of this.
+ plpaw (%a2) # load atc for ADDR1
+ plpaw (%a4) # load atc for ADDR1+1
+ plpaw (%a3) # load atc for ADDR2
+ plpaw (%a5) # load atc for ADDR2+1
+
+# push the operand cache lines from the cache if they exist.
+ cpushl %dc,(%a2) # push line for ADDR1
+ cpushl %dc,(%a4) # push line for ADDR1+1
+ cpushl %dc,(%a3) # push line for ADDR2
+ cpushl %dc,(%a5) # push line for ADDR2+1
+
+ mov.l %d1,%a2 # ADDR1
+ addq.l &0x3,%d1
+ mov.l %d1,%a4 # ADDR1+3
+# if ADDR1 was ATC resident before the above "plpaw" and was executed
+# and it was the next entry scheduled for replacement and ADDR2
+# shares the same set, then the "plpaw" for ADDR2 can push the ADDR1
+# entries from the ATC. so, we do a second set of "plpa"s.
+ plpar (%a2) # load atc for ADDR1
+ plpar (%a4) # load atc for ADDR1+3
+
+# load the BUSCR values.
+ mov.l &0x80000000,%a2 # assert LOCK* buscr value
+ mov.l &0xa0000000,%a3 # assert LOCKE* buscr value
+ mov.l &0x00000000,%a4 # buscr unlock value
+
+# there are two possible mis-aligned cases for word cas. they
+# are separated because the final write which asserts LOCKE* must
+# be aligned.
+ mov.l %a0,%d0 # is ADDR1 misaligned?
+ btst &0x0,%d0
+ bne.w CAS2W2_ENTER # yes
+ bra.b CAS2W_ENTER # no
+
+#
+# D0 = dst operand 1 <-
+# D1 = dst operand 2 <-
+# D2 = cmp operand 1
+# D3 = cmp operand 2
+# D4 = update oper 1
+# D5 = update oper 2
+# D6 = old SFC/DFC
+# D7 = old SR
+# A0 = ADDR1
+# A1 = ADDR2
+# A2 = bus LOCK* value
+# A3 = bus LOCKE* value
+# A4 = bus unlock value
+# A5 = xxxxxxxx
+#
+ align 0x10
+CAS2W_START:
+ movc %a2,%buscr # assert LOCK*
+ movs.w (%a1),%d1 # fetch Dest2[15:0]
+ movs.w (%a0),%d0 # fetch Dest1[15:0]
+ bra.b CAS2W_CONT2
+CAS2W_ENTER:
+ bra.b ~+16
+
+CAS2W_CONT2:
+ cmp.w %d0,%d2 # Dest1 - Compare1
+ bne.b CAS2W_NOUPDATE
+ cmp.w %d1,%d3 # Dest2 - Compare2
+ bne.b CAS2W_NOUPDATE
+ movs.w %d5,(%a1) # Update2[15:0] -> DEST2
+ bra.b CAS2W_UPDATE
+ bra.b ~+16
+
+CAS2W_UPDATE:
+ movc %a3,%buscr # assert LOCKE*
+ movs.w %d4,(%a0) # Update1[15:0] -> DEST1
+ movc %a4,%buscr # unlock the bus
+ bra.b cas2w_update_done
+ bra.b ~+16
+
+CAS2W_NOUPDATE:
+ movc %a3,%buscr # assert LOCKE*
+ movs.w %d0,(%a0) # Dest1[15:0] -> DEST1
+ movc %a4,%buscr # unlock the bus
+ bra.b cas2w_noupdate_done
+ bra.b ~+16
+
+CAS2W_FILLER:
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ bra.b CAS2W_START
+
+####
+
+#################################################################
+# THIS MUST BE THE STATE OF THE INTEGER REGISTER FILE UPON #
+# ENTERING _isp_cas2(). #
+# #
+# D0 = destination[15:0] operand 1 #
+# D1 = destination[15:0] operand 2 #
+# D2 = cmp[15:0] operand 1 #
+# D3 = cmp[15:0] operand 2 #
+# D4 = 'xxxxxx11 -> no reg update; 'xxxxxx00 -> update required #
+# D5 = xxxxxxxx #
+# D6 = xxxxxxxx #
+# D7 = xxxxxxxx #
+# A0 = xxxxxxxx #
+# A1 = xxxxxxxx #
+# A2 = xxxxxxxx #
+# A3 = xxxxxxxx #
+# A4 = xxxxxxxx #
+# A5 = xxxxxxxx #
+# A6 = frame pointer #
+# A7 = stack pointer #
+#################################################################
+
+cas2w_noupdate_done:
+
+# restore previous SFC/DFC value.
+ movc %d6,%sfc # restore old SFC
+ movc %d6,%dfc # restore old DFC
+
+# restore previous interrupt mask level.
+ mov.w %d7,%sr # restore old SR
+
+ sf %d4 # indicate no update was done
+ bra.l _isp_cas2_finish
+
+cas2w_update_done:
+
+# restore previous SFC/DFC value.
+ movc %d6,%sfc # restore old SFC
+ movc %d6,%dfc # restore old DFC
+
+# restore previous interrupt mask level.
+ mov.w %d7,%sr # restore old SR
+
+ st %d4 # indicate update was done
+ bra.l _isp_cas2_finish
+####
+
+ align 0x10
+CAS2W2_START:
+ movc %a2,%buscr # assert LOCK*
+ movs.w (%a1),%d1 # fetch Dest2[15:0]
+ movs.w (%a0),%d0 # fetch Dest1[15:0]
+ bra.b CAS2W2_CONT2
+CAS2W2_ENTER:
+ bra.b ~+16
+
+CAS2W2_CONT2:
+ cmp.w %d0,%d2 # Dest1 - Compare1
+ bne.b CAS2W2_NOUPDATE
+ cmp.w %d1,%d3 # Dest2 - Compare2
+ bne.b CAS2W2_NOUPDATE
+ movs.w %d5,(%a1) # Update2[15:0] -> DEST2
+ bra.b CAS2W2_UPDATE
+ bra.b ~+16
+
+CAS2W2_UPDATE:
+ ror.l &0x8,%d4 # get Update1[15:8]
+ movs.b %d4,(%a0)+ # Update1[15:8] -> DEST1
+ movc %a3,%buscr # assert LOCKE*
+ rol.l &0x8,%d4 # get Update1[7:0]
+ bra.b CAS2W2_UPDATE2
+ bra.b ~+16
+
+CAS2W2_UPDATE2:
+ movs.b %d4,(%a0) # Update1[7:0] -> DEST1+0x1
+ movc %a4,%buscr # unlock the bus
+ bra.w cas2w_update_done
+ nop
+ bra.b ~+16
+
+CAS2W2_NOUPDATE:
+ ror.l &0x8,%d0 # get Dest1[15:8]
+ movs.b %d0,(%a0)+ # Dest1[15:8] -> DEST1
+ movc %a3,%buscr # assert LOCKE*
+ rol.l &0x8,%d0 # get Dest1[7:0]
+ bra.b CAS2W2_NOUPDATE2
+ bra.b ~+16
+
+CAS2W2_NOUPDATE2:
+ movs.b %d0,(%a0) # Dest1[7:0] -> DEST1+0x1
+ movc %a4,%buscr # unlock the bus
+ bra.w cas2w_noupdate_done
+ nop
+ bra.b ~+16
+
+CAS2W2_FILLER:
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ bra.b CAS2W2_START
+
+# ###### ## ######
+# # # # #
+# # ###### ######
+# # # # #
+# ###### # # ######
+
+#########################################################################
+# XDEF **************************************************************** #
+# _isp_cas(): "core" emulation code for the cas instruction #
+# #
+# XREF **************************************************************** #
+# _isp_cas_finish() - only exit point for this emulation code; #
+# do clean-up #
+# #
+# INPUT *************************************************************** #
+# *see entry chart below* #
+# #
+# OUTPUT ************************************************************** #
+# *see exit chart below* #
+# #
+# ALGORITHM *********************************************************** #
+# (1) Make several copies of the effective address. #
+# (2) Save current SR; Then mask off all maskable interrupts. #
+# (3) Save current DFC/SFC (ASSUMED TO BE EQUAL!!!); Then set #
+# SFC/DFC according to whether exception occurred in user or #
+# supervisor mode. #
+# (4) Use "plpaw" instruction to pre-load ATC with efective #
+# address page(s). THIS SHOULD NOT FAULT!!! The relevant #
+# page(s) should have been made resident prior to entering #
+# this routine. #
+# (5) Push the operand lines from the cache w/ "cpushl". #
+# In the 68040, this was done within the locked region. In #
+# the 68060, it is done outside of the locked region. #
+# (6) Pre-fetch the core emulation instructions by executing one #
+# branch within each physical line (16 bytes) of the code #
+# before actually executing the code. #
+# (7) Load the BUSCR with the bus lock value. #
+# (8) Fetch the source operand. #
+# (9) Do the compare. If equal, go to step (12). #
+# (10)Unequal. No update occurs. But, we do write the DST op back #
+# to itself (as w/ the '040) so we can gracefully unlock #
+# the bus (and assert LOCKE*) using BUSCR and the final move. #
+# (11)Exit. #
+# (12)Write update operand to the DST location. Use BUSCR to #
+# assert LOCKE* for the final write operation. #
+# (13)Exit. #
+# #
+# The algorithm is actually implemented slightly differently #
+# depending on the size of the operation and the misalignment of the #
+# operand. A misaligned operand must be written in aligned chunks or #
+# else the BUSCR register control gets confused. #
+# #
+#########################################################################
+
+#########################################################
+# THIS IS THE STATE OF THE INTEGER REGISTER FILE UPON #
+# ENTERING _isp_cas(). #
+# #
+# D0 = xxxxxxxx #
+# D1 = xxxxxxxx #
+# D2 = update operand #
+# D3 = xxxxxxxx #
+# D4 = compare operand #
+# D5 = xxxxxxxx #
+# D6 = supervisor ('xxxxxxff) or user mode ('xxxxxx00) #
+# D7 = longword ('xxxxxxff) or word size ('xxxxxx00) #
+# A0 = ADDR #
+# A1 = xxxxxxxx #
+# A2 = xxxxxxxx #
+# A3 = xxxxxxxx #
+# A4 = xxxxxxxx #
+# A5 = xxxxxxxx #
+# A6 = frame pointer #
+# A7 = stack pointer #
+#########################################################
+
+ global _isp_cas
+_isp_cas:
+ tst.b %d6 # user or supervisor mode?
+ bne.b cas_super # supervisor
+cas_user:
+ movq.l &0x1,%d0 # load user data fc
+ bra.b cas_cont
+cas_super:
+ movq.l &0x5,%d0 # load supervisor data fc
+
+cas_cont:
+ tst.b %d7 # word or longword?
+ bne.w casl # longword
+
+####
+casw:
+ mov.l %a0,%a1 # make copy for plpaw1
+ mov.l %a0,%a2 # make copy for plpaw2
+ addq.l &0x1,%a2 # plpaw2 points to end of word
+
+ mov.l %d2,%d3 # d3 = update[7:0]
+ lsr.w &0x8,%d2 # d2 = update[15:8]
+
+# mask interrupt levels 0-6. save old mask value.
+ mov.w %sr,%d7 # save current SR
+ ori.w &0x0700,%sr # inhibit interrupts
+
+# load the SFC and DFC with the appropriate mode.
+ movc %sfc,%d6 # save old SFC/DFC
+ movc %d0,%sfc # load new sfc
+ movc %d0,%dfc # load new dfc
+
+# pre-load the operand ATC. no page faults should occur here because
+# _real_lock_page() should have taken care of this.
+ plpaw (%a1) # load atc for ADDR
+ plpaw (%a2) # load atc for ADDR+1
+
+# push the operand lines from the cache if they exist.
+ cpushl %dc,(%a1) # push dirty data
+ cpushl %dc,(%a2) # push dirty data
+
+# load the BUSCR values.
+ mov.l &0x80000000,%a1 # assert LOCK* buscr value
+ mov.l &0xa0000000,%a2 # assert LOCKE* buscr value
+ mov.l &0x00000000,%a3 # buscr unlock value
+
+# pre-load the instruction cache for the following algorithm.
+# this will minimize the number of cycles that LOCK* will be asserted.
+ bra.b CASW_ENTER # start pre-loading icache
+
+#
+# D0 = dst operand <-
+# D1 = update[15:8] operand
+# D2 = update[7:0] operand
+# D3 = xxxxxxxx
+# D4 = compare[15:0] operand
+# D5 = xxxxxxxx
+# D6 = old SFC/DFC
+# D7 = old SR
+# A0 = ADDR
+# A1 = bus LOCK* value
+# A2 = bus LOCKE* value
+# A3 = bus unlock value
+# A4 = xxxxxxxx
+# A5 = xxxxxxxx
+#
+ align 0x10
+CASW_START:
+ movc %a1,%buscr # assert LOCK*
+ movs.w (%a0),%d0 # fetch Dest[15:0]
+ cmp.w %d0,%d4 # Dest - Compare
+ bne.b CASW_NOUPDATE
+ bra.b CASW_UPDATE
+CASW_ENTER:
+ bra.b ~+16
+
+CASW_UPDATE:
+ movs.b %d2,(%a0)+ # Update[15:8] -> DEST
+ movc %a2,%buscr # assert LOCKE*
+ movs.b %d3,(%a0) # Update[7:0] -> DEST+0x1
+ bra.b CASW_UPDATE2
+ bra.b ~+16
+
+CASW_UPDATE2:
+ movc %a3,%buscr # unlock the bus
+ bra.b casw_update_done
+ nop
+ nop
+ nop
+ nop
+ bra.b ~+16
+
+CASW_NOUPDATE:
+ ror.l &0x8,%d0 # get Dest[15:8]
+ movs.b %d0,(%a0)+ # Dest[15:8] -> DEST
+ movc %a2,%buscr # assert LOCKE*
+ rol.l &0x8,%d0 # get Dest[7:0]
+ bra.b CASW_NOUPDATE2
+ bra.b ~+16
+
+CASW_NOUPDATE2:
+ movs.b %d0,(%a0) # Dest[7:0] -> DEST+0x1
+ movc %a3,%buscr # unlock the bus
+ bra.b casw_noupdate_done
+ nop
+ nop
+ bra.b ~+16
+
+CASW_FILLER:
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ bra.b CASW_START
+
+#################################################################
+# THIS MUST BE THE STATE OF THE INTEGER REGISTER FILE UPON #
+# CALLING _isp_cas_finish(). #
+# #
+# D0 = destination[15:0] operand #
+# D1 = 'xxxxxx11 -> no reg update; 'xxxxxx00 -> update required #
+# D2 = xxxxxxxx #
+# D3 = xxxxxxxx #
+# D4 = compare[15:0] operand #
+# D5 = xxxxxxxx #
+# D6 = xxxxxxxx #
+# D7 = xxxxxxxx #
+# A0 = xxxxxxxx #
+# A1 = xxxxxxxx #
+# A2 = xxxxxxxx #
+# A3 = xxxxxxxx #
+# A4 = xxxxxxxx #
+# A5 = xxxxxxxx #
+# A6 = frame pointer #
+# A7 = stack pointer #
+#################################################################
+
+casw_noupdate_done:
+
+# restore previous SFC/DFC value.
+ movc %d6,%sfc # restore old SFC
+ movc %d6,%dfc # restore old DFC
+
+# restore previous interrupt mask level.
+ mov.w %d7,%sr # restore old SR
+
+ sf %d1 # indicate no update was done
+ bra.l _isp_cas_finish
+
+casw_update_done:
+
+# restore previous SFC/DFC value.
+ movc %d6,%sfc # restore old SFC
+ movc %d6,%dfc # restore old DFC
+
+# restore previous interrupt mask level.
+ mov.w %d7,%sr # restore old SR
+
+ st %d1 # indicate update was done
+ bra.l _isp_cas_finish
+
+################
+
+# there are two possible mis-aligned cases for longword cas. they
+# are separated because the final write which asserts LOCKE* must
+# be an aligned write.
+casl:
+ mov.l %a0,%a1 # make copy for plpaw1
+ mov.l %a0,%a2 # make copy for plpaw2
+ addq.l &0x3,%a2 # plpaw2 points to end of longword
+
+ mov.l %a0,%d1 # byte or word misaligned?
+ btst &0x0,%d1
+ bne.w casl2 # byte misaligned
+
+ mov.l %d2,%d3 # d3 = update[15:0]
+ swap %d2 # d2 = update[31:16]
+
+# mask interrupts levels 0-6. save old mask value.
+ mov.w %sr,%d7 # save current SR
+ ori.w &0x0700,%sr # inhibit interrupts
+
+# load the SFC and DFC with the appropriate mode.
+ movc %sfc,%d6 # save old SFC/DFC
+ movc %d0,%sfc # load new sfc
+ movc %d0,%dfc # load new dfc
+
+# pre-load the operand ATC. no page faults should occur here because
+# _real_lock_page() should have taken care of this.
+ plpaw (%a1) # load atc for ADDR
+ plpaw (%a2) # load atc for ADDR+3
+
+# push the operand lines from the cache if they exist.
+ cpushl %dc,(%a1) # push dirty data
+ cpushl %dc,(%a2) # push dirty data
+
+# load the BUSCR values.
+ mov.l &0x80000000,%a1 # assert LOCK* buscr value
+ mov.l &0xa0000000,%a2 # assert LOCKE* buscr value
+ mov.l &0x00000000,%a3 # buscr unlock value
+
+ bra.b CASL_ENTER # start pre-loading icache
+
+#
+# D0 = dst operand <-
+# D1 = xxxxxxxx
+# D2 = update[31:16] operand
+# D3 = update[15:0] operand
+# D4 = compare[31:0] operand
+# D5 = xxxxxxxx
+# D6 = old SFC/DFC
+# D7 = old SR
+# A0 = ADDR
+# A1 = bus LOCK* value
+# A2 = bus LOCKE* value
+# A3 = bus unlock value
+# A4 = xxxxxxxx
+# A5 = xxxxxxxx
+#
+ align 0x10
+CASL_START:
+ movc %a1,%buscr # assert LOCK*
+ movs.l (%a0),%d0 # fetch Dest[31:0]
+ cmp.l %d0,%d4 # Dest - Compare
+ bne.b CASL_NOUPDATE
+ bra.b CASL_UPDATE
+CASL_ENTER:
+ bra.b ~+16
+
+CASL_UPDATE:
+ movs.w %d2,(%a0)+ # Update[31:16] -> DEST
+ movc %a2,%buscr # assert LOCKE*
+ movs.w %d3,(%a0) # Update[15:0] -> DEST+0x2
+ bra.b CASL_UPDATE2
+ bra.b ~+16
+
+CASL_UPDATE2:
+ movc %a3,%buscr # unlock the bus
+ bra.b casl_update_done
+ nop
+ nop
+ nop
+ nop
+ bra.b ~+16
+
+CASL_NOUPDATE:
+ swap %d0 # get Dest[31:16]
+ movs.w %d0,(%a0)+ # Dest[31:16] -> DEST
+ swap %d0 # get Dest[15:0]
+ movc %a2,%buscr # assert LOCKE*
+ bra.b CASL_NOUPDATE2
+ bra.b ~+16
+
+CASL_NOUPDATE2:
+ movs.w %d0,(%a0) # Dest[15:0] -> DEST+0x2
+ movc %a3,%buscr # unlock the bus
+ bra.b casl_noupdate_done
+ nop
+ nop
+ bra.b ~+16
+
+CASL_FILLER:
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ bra.b CASL_START
+
+#################################################################
+# THIS MUST BE THE STATE OF THE INTEGER REGISTER FILE UPON #
+# CALLING _isp_cas_finish(). #
+# #
+# D0 = destination[31:0] operand #
+# D1 = 'xxxxxx11 -> no reg update; 'xxxxxx00 -> update required #
+# D2 = xxxxxxxx #
+# D3 = xxxxxxxx #
+# D4 = compare[31:0] operand #
+# D5 = xxxxxxxx #
+# D6 = xxxxxxxx #
+# D7 = xxxxxxxx #
+# A0 = xxxxxxxx #
+# A1 = xxxxxxxx #
+# A2 = xxxxxxxx #
+# A3 = xxxxxxxx #
+# A4 = xxxxxxxx #
+# A5 = xxxxxxxx #
+# A6 = frame pointer #
+# A7 = stack pointer #
+#################################################################
+
+casl_noupdate_done:
+
+# restore previous SFC/DFC value.
+ movc %d6,%sfc # restore old SFC
+ movc %d6,%dfc # restore old DFC
+
+# restore previous interrupt mask level.
+ mov.w %d7,%sr # restore old SR
+
+ sf %d1 # indicate no update was done
+ bra.l _isp_cas_finish
+
+casl_update_done:
+
+# restore previous SFC/DFC value.
+ movc %d6,%sfc # restore old SFC
+ movc %d6,%dfc # restore old DFC
+
+# restore previous interrupts mask level.
+ mov.w %d7,%sr # restore old SR
+
+ st %d1 # indicate update was done
+ bra.l _isp_cas_finish
+
+#######################################
+casl2:
+ mov.l %d2,%d5 # d5 = Update[7:0]
+ lsr.l &0x8,%d2
+ mov.l %d2,%d3 # d3 = Update[23:8]
+ swap %d2 # d2 = Update[31:24]
+
+# mask interrupts levels 0-6. save old mask value.
+ mov.w %sr,%d7 # save current SR
+ ori.w &0x0700,%sr # inhibit interrupts
+
+# load the SFC and DFC with the appropriate mode.
+ movc %sfc,%d6 # save old SFC/DFC
+ movc %d0,%sfc # load new sfc
+ movc %d0,%dfc # load new dfc
+
+# pre-load the operand ATC. no page faults should occur here because
+# _real_lock_page() should have taken care of this already.
+ plpaw (%a1) # load atc for ADDR
+ plpaw (%a2) # load atc for ADDR+3
+
+# puch the operand lines from the cache if they exist.
+ cpushl %dc,(%a1) # push dirty data
+ cpushl %dc,(%a2) # push dirty data
+
+# load the BUSCR values.
+ mov.l &0x80000000,%a1 # assert LOCK* buscr value
+ mov.l &0xa0000000,%a2 # assert LOCKE* buscr value
+ mov.l &0x00000000,%a3 # buscr unlock value
+
+# pre-load the instruction cache for the following algorithm.
+# this will minimize the number of cycles that LOCK* will be asserted.
+ bra.b CASL2_ENTER # start pre-loading icache
+
+#
+# D0 = dst operand <-
+# D1 = xxxxxxxx
+# D2 = update[31:24] operand
+# D3 = update[23:8] operand
+# D4 = compare[31:0] operand
+# D5 = update[7:0] operand
+# D6 = old SFC/DFC
+# D7 = old SR
+# A0 = ADDR
+# A1 = bus LOCK* value
+# A2 = bus LOCKE* value
+# A3 = bus unlock value
+# A4 = xxxxxxxx
+# A5 = xxxxxxxx
+#
+ align 0x10
+CASL2_START:
+ movc %a1,%buscr # assert LOCK*
+ movs.l (%a0),%d0 # fetch Dest[31:0]
+ cmp.l %d0,%d4 # Dest - Compare
+ bne.b CASL2_NOUPDATE
+ bra.b CASL2_UPDATE
+CASL2_ENTER:
+ bra.b ~+16
+
+CASL2_UPDATE:
+ movs.b %d2,(%a0)+ # Update[31:24] -> DEST
+ movs.w %d3,(%a0)+ # Update[23:8] -> DEST+0x1
+ movc %a2,%buscr # assert LOCKE*
+ bra.b CASL2_UPDATE2
+ bra.b ~+16
+
+CASL2_UPDATE2:
+ movs.b %d5,(%a0) # Update[7:0] -> DEST+0x3
+ movc %a3,%buscr # unlock the bus
+ bra.w casl_update_done
+ nop
+ bra.b ~+16
+
+CASL2_NOUPDATE:
+ rol.l &0x8,%d0 # get Dest[31:24]
+ movs.b %d0,(%a0)+ # Dest[31:24] -> DEST
+ swap %d0 # get Dest[23:8]
+ movs.w %d0,(%a0)+ # Dest[23:8] -> DEST+0x1
+ bra.b CASL2_NOUPDATE2
+ bra.b ~+16
+
+CASL2_NOUPDATE2:
+ rol.l &0x8,%d0 # get Dest[7:0]
+ movc %a2,%buscr # assert LOCKE*
+ movs.b %d0,(%a0) # Dest[7:0] -> DEST+0x3
+ bra.b CASL2_NOUPDATE3
+ nop
+ bra.b ~+16
+
+CASL2_NOUPDATE3:
+ movc %a3,%buscr # unlock the bus
+ bra.w casl_noupdate_done
+ nop
+ nop
+ nop
+ bra.b ~+16
+
+CASL2_FILLER:
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ bra.b CASL2_START
+
+####
+####
+# end label used by _isp_cas_inrange()
+ global _CASHI
+_CASHI: