diff options
Diffstat (limited to 'board/samsung/smdk5250/monitor.S')
| -rw-r--r-- | board/samsung/smdk5250/monitor.S | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/board/samsung/smdk5250/monitor.S b/board/samsung/smdk5250/monitor.S new file mode 100644 index 000000000..8bc21d8f5 --- /dev/null +++ b/board/samsung/smdk5250/monitor.S @@ -0,0 +1,97 @@ +/* + * + * Copyright (c) 2012 Christoffer Dall <c.dall@virtualopensystems.com> + * <cdall@cs.columbia.edu> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <config.h> + +.syntax unified +.arch_extension sec +.arch_extension virt +.text + +.align 5 + +/* We use the same vector table for Hyp and Monitor mode, since + * we will only use each once and they don't overlap. + */ +mon_vectors: + .word 0 /* reset */ + .word 0 /* undef */ + b 2f /* smc */ + .word 0 /* pabt */ + .word 0 /* dabt */ + b 1f + .word 0 /* irq */ + .word 0 /* fiq */ + +/* Return directly back to the caller without leaving Hyp mode: */ +1: mrs lr, elr_hyp + mov pc, lr + +/* In monitor mode, set up HVBAR and SCR then return to caller in NS-SVC. */ +2: + mrc p15, 0, r1, c1, c1, 0 @ SCR + /* + * Set SCR.NS=1 (needed for setting HVBAR and also returning to NS state) + * .IRQ,FIQ,EA=0 (don't take aborts/exceptions to Monitor mode) + * .FW,AW=1 (CPSR.A,F modifiable in NS state) + * .nET=0 (early termination OK) + * .SCD=0 (SMC in NS mode OK, so we can call secure firmware) + * .HCE=1 (HVC does Hyp call) + */ + bic r1, r1, #0x07f + ldr r2, =0x131 + orr r1, r1, r2 + mcr p15, 0, r2, c1, c1, 0 @ SCR + isb + ldr r2, =mon_vectors + mcr p15, 4, r2, c12, c0, 0 @ set HVBAR + /* ...and return to calling code in NS state */ + movs pc, lr + +/****************************************************************************** + * This code is called from u-boot into the above handler + */ + + .globl monitor_init +monitor_init: + ldr ip, =mon_vectors + mcr p15, 0, ip, c12, c0, 1 @ Monitor vector base address + mov pc, lr + + /* Try to go into NS-SVC: void enter_ns(void); */ + .globl enter_ns +enter_ns: + smc #0 + mov pc, lr + + /* void enter_hyp(void); */ + .globl enter_hyp +enter_hyp: + /* Now we're in NS-SVC, make a Hyp call to get into Hyp mode */ + mov r0, lr + mov r1, sp + hvc #0 + /* We will end up here in NS-Hyp. */ + mov sp, r1 + mov pc, r0 |