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authorwdenk <wdenk>2003-03-06 00:58:30 +0000
committerwdenk <wdenk>2003-03-06 00:58:30 +0000
commitdb2f721ffcf9693086a7e5c6c7015f2019e7f52e (patch)
tree1d755e28c035c1247f30b570ed239a097a7d13c8 /board/lubbock
parent43d9616cffb4a130e1620e3e33fc9bc1bcabe399 (diff)
* Patch by Rune Torgersen, 13 Feb 2003:LABEL_2003_03_06_0200
Add support for Motorola MPC8266ADS board * Patch by Kyle Harris, 19 Feb 2003: patches for the Intel lubbock board: memsetup.S - general cleanup (based on Robert's csb226 code) flash.c - overhaul, actually works now lubbock.c - fix init funcs to return proper value * Patch by Kenneth Johansson, 26 Feb 2003: - Fixed off by one in RFTA calculation. - No need to abort when LDF is lower than we can program it's only minimum timing so clamp it to what we can do. - Takes function pointer to function for reading the spd_nvram. Usefull for faking data or hardcode a module without the nvram. - fix other user for above change - fix some comments. * Patches by Brian Waite, 26 Feb 2003: - fix port for evb64260 board - fix PCI for evb64260 board - fix PCI scan * Patch by Reinhard Meyer, 1 Mar 2003: Add support for EMK TOP860 Module * Patch by Yuli Barcohen, 02 Mar 2003: Add SPD EEPROM support for MPC8260ADS board
Diffstat (limited to 'board/lubbock')
-rw-r--r--board/lubbock/config.mk9
-rw-r--r--board/lubbock/flash.c467
-rw-r--r--board/lubbock/lubbock.c6
-rw-r--r--board/lubbock/memsetup.S665
4 files changed, 435 insertions, 712 deletions
diff --git a/board/lubbock/config.mk b/board/lubbock/config.mk
index d6ec08cf1..0ffe1ba63 100644
--- a/board/lubbock/config.mk
+++ b/board/lubbock/config.mk
@@ -1,12 +1,3 @@
-#
-# Linux-Kernel is expected to be at c000'8000, entry c000'8000
-#
-# we load ourself to c170'0000, the upper 1 MB of second bank
-#
-# download areas is c800'0000
-#
-
-
#TEXT_BASE = 0xa1700000
TEXT_BASE = 0xa3000000
#TEXT_BASE = 0
diff --git a/board/lubbock/flash.c b/board/lubbock/flash.c
index 84c09a853..a93875083 100644
--- a/board/lubbock/flash.c
+++ b/board/lubbock/flash.c
@@ -1,10 +1,9 @@
/*
- * (C) Copyright 2002
+ * (C) Copyright 2001
* Kyle Harris, Nexus Technologies, Inc. kharris@nexus-tech.net
*
- * (C) Copyright 2002
- * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
- * Marius Groeger <mgroeger@sysgo.de>
+ * (C) Copyright 2001
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
@@ -26,46 +25,62 @@
*/
#include <common.h>
+#include <linux/byteorder/swab.h>
-#define FLASH_BANK_SIZE 0x2000000
-#define MAIN_SECT_SIZE 0x40000 /* 2x16 = 256k per sector */
-flash_info_t flash_info[CFG_MAX_FLASH_BANKS];
+flash_info_t flash_info[CFG_MAX_FLASH_BANKS]; /* info for FLASH chips */
+/* Board support for 1 or 2 flash devices */
+#define FLASH_PORT_WIDTH32
+#undef FLASH_PORT_WIDTH16
+
+#ifdef FLASH_PORT_WIDTH16
+#define FLASH_PORT_WIDTH ushort
+#define FLASH_PORT_WIDTHV vu_short
+#define SWAP(x) __swab16(x)
+#else
+#define FLASH_PORT_WIDTH ulong
+#define FLASH_PORT_WIDTHV vu_long
+#define SWAP(x) __swab32(x)
+#endif
+
+#define FPW FLASH_PORT_WIDTH
+#define FPWV FLASH_PORT_WIDTHV
+
+#define mb() __asm__ __volatile__ ("" : : : "memory")
/*-----------------------------------------------------------------------
+ * Functions
*/
+static ulong flash_get_size (FPW *addr, flash_info_t *info);
+static int write_data (flash_info_t *info, ulong dest, FPW data);
+static void flash_get_offsets (ulong base, flash_info_t *info);
+void inline spin_wheel(void);
-ulong flash_init(void)
+/*-----------------------------------------------------------------------
+ */
+
+unsigned long flash_init (void)
{
- int i, j;
+ int i;
ulong size = 0;
for (i = 0; i < CFG_MAX_FLASH_BANKS; i++)
{
- ulong flashbase = 0;
- flash_info[i].flash_id =
- (INTEL_MANUFACT & FLASH_VENDMASK) |
- (INTEL_ID_28F128J3 & FLASH_TYPEMASK);
- flash_info[i].size = FLASH_BANK_SIZE;
- flash_info[i].sector_count = CFG_MAX_FLASH_SECT;
- memset(flash_info[i].protect, 0, CFG_MAX_FLASH_SECT);
switch (i)
{
case 0:
- flashbase = PHYS_FLASH_1;
+ flash_get_size((FPW *)PHYS_FLASH_1, &flash_info[i]);
+ flash_get_offsets(PHYS_FLASH_1, &flash_info[i]);
break;
case 1:
- flashbase = PHYS_FLASH_2;
+ flash_get_size((FPW *)PHYS_FLASH_2, &flash_info[i]);
+ flash_get_offsets(PHYS_FLASH_2, &flash_info[i]);
break;
default:
panic("configured to many flash banks!\n");
break;
}
- for (j = 0; j < flash_info[i].sector_count; j++)
- {
- flash_info[i].start[j] = flashbase + j*MAIN_SECT_SIZE;
- }
size += flash_info[i].size;
}
@@ -86,71 +101,140 @@ ulong flash_init(void)
/*-----------------------------------------------------------------------
*/
+static void flash_get_offsets (ulong base, flash_info_t *info)
+{
+ int i;
+
+ if (info->flash_id == FLASH_UNKNOWN) {
+ return;
+ }
+
+ if ((info->flash_id & FLASH_VENDMASK) == FLASH_MAN_INTEL) {
+ for (i = 0; i < info->sector_count; i++) {
+ info->start[i] = base + (i * PHYS_FLASH_SECT_SIZE);
+ info->protect[i] = 0;
+ }
+ }
+}
+
+/*-----------------------------------------------------------------------
+ */
void flash_print_info (flash_info_t *info)
{
- int i, j;
+ int i;
- for (j=0; j<CFG_MAX_FLASH_BANKS; j++)
- {
- switch (info->flash_id & FLASH_VENDMASK)
- {
- case (INTEL_MANUFACT & FLASH_VENDMASK):
- printf("Intel: ");
- break;
- default:
- printf("Unknown Vendor ");
- break;
+ if (info->flash_id == FLASH_UNKNOWN) {
+ printf ("missing or unknown FLASH type\n");
+ return;
}
- switch (info->flash_id & FLASH_TYPEMASK)
- {
- case (INTEL_ID_28F128J3 & FLASH_TYPEMASK):
- printf("28F128J3 (128Mbit)\n");
- break;
- default:
- printf("Unknown Chip Type\n");
- goto Done;
- break;
+ switch (info->flash_id & FLASH_VENDMASK) {
+ case FLASH_MAN_INTEL: printf ("INTEL "); break;
+ default: printf ("Unknown Vendor "); break;
+ }
+
+ switch (info->flash_id & FLASH_TYPEMASK) {
+ case FLASH_28F128J3A:
+ printf ("28F128J3A\n"); break;
+ default: printf ("Unknown Chip Type\n"); break;
}
- printf(" Size: %ld MB in %d Sectors\n",
+ printf (" Size: %ld MB in %d Sectors\n",
info->size >> 20, info->sector_count);
- printf(" Sector Start Addresses:");
- for (i = 0; i < info->sector_count; i++)
- {
+ printf (" Sector Start Addresses:");
+ for (i=0; i<info->sector_count; ++i) {
if ((i % 5) == 0)
- {
printf ("\n ");
- }
- printf (" %08lX%s", info->start[i],
- info->protect[i] ? " (RO)" : " ");
+ printf (" %08lX%s",
+ info->start[i],
+ info->protect[i] ? " (RO)" : " "
+ );
}
printf ("\n");
- info++;
+ return;
+}
+
+/*
+ * The following code cannot be run from FLASH!
+ */
+static ulong flash_get_size (FPW *addr, flash_info_t *info)
+{
+ volatile FPW value;
+
+ /* Write auto select command: read Manufacturer ID */
+ addr[0x5555] = (FPW)0x00AA00AA;
+ addr[0x2AAA] = (FPW)0x00550055;
+ addr[0x5555] = (FPW)0x00900090;
+
+ mb();
+ value = addr[0];
+
+ switch (value) {
+
+ case (FPW)INTEL_MANUFACT:
+ info->flash_id = FLASH_MAN_INTEL;
+ break;
+
+ default:
+ info->flash_id = FLASH_UNKNOWN;
+ info->sector_count = 0;
+ info->size = 0;
+ addr[0] = (FPW)0x00FF00FF; /* restore read mode */
+ return (0); /* no or unknown flash */
+ }
+
+ mb();
+ value = addr[1]; /* device ID */
+
+ switch (value) {
+
+ case (FPW)INTEL_ID_28F128J3A:
+ info->flash_id += FLASH_28F128J3A;
+ info->sector_count = 128;
+ info->size = 0x02000000;
+ break; /* => 16 MB */
+
+ default:
+ info->flash_id = FLASH_UNKNOWN;
+ break;
+ }
+
+ if (info->sector_count > CFG_MAX_FLASH_SECT) {
+ printf ("** ERROR: sector count %d > max (%d) **\n",
+ info->sector_count, CFG_MAX_FLASH_SECT);
+ info->sector_count = CFG_MAX_FLASH_SECT;
}
-Done:
+ addr[0] = (FPW)0x00FF00FF; /* restore read mode */
+
+ return (info->size);
}
+
/*-----------------------------------------------------------------------
*/
int flash_erase (flash_info_t *info, int s_first, int s_last)
{
int flag, prot, sect;
- int rc = ERR_OK;
-
- if (info->flash_id == FLASH_UNKNOWN)
- return ERR_UNKNOWN_FLASH_TYPE;
+ ulong type, start, now, last;
+ int rcode = 0;
if ((s_first < 0) || (s_first > s_last)) {
- return ERR_INVAL;
+ if (info->flash_id == FLASH_UNKNOWN) {
+ printf ("- missing\n");
+ } else {
+ printf ("- no sectors to erase\n");
+ }
+ return 1;
}
- if ((info->flash_id & FLASH_VENDMASK) !=
- (INTEL_MANUFACT & FLASH_VENDMASK)) {
- return ERR_UNKNOWN_FLASH_VENDOR;
+ type = (info->flash_id & FLASH_VENDMASK);
+ if ((type != FLASH_MAN_INTEL)) {
+ printf ("Can't erase unknown flash type %08lx - aborted\n",
+ info->flash_id);
+ return 1;
}
prot = 0;
@@ -159,153 +243,79 @@ int flash_erase (flash_info_t *info, int s_first, int s_last)
prot++;
}
}
- if (prot)
- return ERR_PROTECTED;
- /*
- * Disable interrupts which might cause a timeout
- * here. Remember that our exception vectors are
- * at address 0 in the flash, and we don't want a
- * (ticker) exception to happen while the flash
- * chip is in programming mode.
- */
+ if (prot) {
+ printf ("- Warning: %d protected sectors will not be erased!\n",
+ prot);
+ } else {
+ printf ("\n");
+ }
+
+ start = get_timer (0);
+ last = start;
+
+ /* Disable interrupts which might cause a timeout here */
flag = disable_interrupts();
/* Start erase on unprotected sectors */
- for (sect = s_first; sect<=s_last && !ctrlc(); sect++) {
+ for (sect = s_first; sect<=s_last; sect++) {
+ if (info->protect[sect] == 0) { /* not protected */
+ FPWV *addr = (FPWV *)(info->start[sect]);
+ FPW status;
printf("Erasing sector %2d ... ", sect);
/* arm simple, non interrupt dependent timer */
reset_timer_masked();
- if (info->protect[sect] == 0) { /* not protected */
- vu_short *addr = (vu_short *)(info->start[sect]);
+ *addr = (FPW)0x00500050; /* clear status register */
+ *addr = (FPW)0x00200020; /* erase setup */
+ *addr = (FPW)0x00D000D0; /* erase confirm */
- *addr = 0x20; /* erase setup */
- *addr = 0xD0; /* erase confirm */
-
- while ((*addr & 0x80) != 0x80) {
+ while (((status = *addr) & (FPW)0x00800080) != (FPW)0x00800080) {
if (get_timer_masked() > CFG_FLASH_ERASE_TOUT) {
- *addr = 0xB0; /* suspend erase */
- *addr = 0xFF; /* reset to read mode */
- rc = ERR_TIMOUT;
- goto outahere;
- }
- }
-
- /* clear status register command */
- *addr = 0x50;
- /* reset to read mode */
- *addr = 0xFF;
+ printf ("Timeout\n");
+ *addr = (FPW)0x00B000B0; /* suspend erase */
+ *addr = (FPW)0x00FF00FF; /* reset to read mode */
+ rcode = 1;
+ break;
}
- printf("ok.\n");
}
- if (ctrlc())
- printf("User Interrupt!\n");
-outahere:
+ *addr = 0x00500050; /* clear status register cmd. */
+ *addr = 0x00FF00FF; /* resest to read mode */
- /* allow flash to settle - wait 10 ms */
- udelay_masked(10000);
-
- if (flag)
- enable_interrupts();
-
- return rc;
-}
-
-/*-----------------------------------------------------------------------
- * Copy memory to flash
- */
-
-static int write_word (flash_info_t *info, ulong dest, ushort data)
-{
- vu_short *addr = (vu_short *)dest, val;
- int rc = ERR_OK;
- int flag;
-
- /* Check if Flash is (sufficiently) erased
- */
- if ((*addr & data) != data)
- return ERR_NOT_ERASED;
-
- /*
- * Disable interrupts which might cause a timeout
- * here. Remember that our exception vectors are
- * at address 0 in the flash, and we don't want a
- * (ticker) exception to happen while the flash
- * chip is in programming mode.
- */
- flag = disable_interrupts();
-
- /* clear status register command */
- *addr = 0x50;
-
- /* program set-up command */
- *addr = 0x40;
-
- /* latch address/data */
- *addr = data;
-
- /* arm simple, non interrupt dependent timer */
- reset_timer_masked();
-
- /* wait while polling the status register */
- while(((val = *addr) & 0x80) != 0x80)
- {
- if (get_timer_masked() > CFG_FLASH_WRITE_TOUT) {
- rc = ERR_TIMOUT;
- /* suspend program command */
- *addr = 0xB0;
- goto outahere;
- }
- }
-
- if(val & 0x1A) { /* check for error */
- printf("\nFlash write error %02x at address %08lx\n",
- (int)val, (unsigned long)dest);
- if(val & (1<<3)) {
- printf("Voltage range error.\n");
- rc = ERR_PROG_ERROR;
- goto outahere;
+ printf (" done\n");
}
- if(val & (1<<1)) {
- printf("Device protect error.\n");
- rc = ERR_PROTECTED;
- goto outahere;
}
- if(val & (1<<4)) {
- printf("Programming error.\n");
- rc = ERR_PROG_ERROR;
- goto outahere;
- }
- rc = ERR_PROG_ERROR;
- goto outahere;
- }
-
-outahere:
- /* read array command */
- *addr = 0xFF;
-
- if (flag)
- enable_interrupts();
-
- return rc;
+ return rcode;
}
/*-----------------------------------------------------------------------
- * Copy memory to flash.
+ * Copy memory to flash, returns:
+ * 0 - OK
+ * 1 - write timeout
+ * 2 - Flash not erased
+ * 4 - Flash not identified
*/
int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
{
ulong cp, wp;
- ushort data;
- int l;
- int i, rc;
+ FPW data;
+ int count, i, l, rc, port_width;
- wp = (addr & ~1); /* get lower word aligned address */
+ if (info->flash_id == FLASH_UNKNOWN) {
+ return 4;
+ }
+/* get lower word aligned address */
+#ifdef FLASH_PORT_WIDTH16
+ wp = (addr & ~1);
+ port_width = 2;
+#else
+ wp = (addr & ~3);
+ port_width = 4;
+#endif
/*
* handle unaligned start bytes
@@ -313,51 +323,110 @@ int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
if ((l = addr - wp) != 0) {
data = 0;
for (i=0, cp=wp; i<l; ++i, ++cp) {
- data = (data >> 8) | (*(uchar *)cp << 8);
+ data = (data << 8) | (*(uchar *)cp);
}
- for (; i<2 && cnt>0; ++i) {
- data = (data >> 8) | (*src++ << 8);
+ for (; i<port_width && cnt>0; ++i) {
+ data = (data << 8) | *src++;
--cnt;
++cp;
}
- for (; cnt==0 && i<2; ++i, ++cp) {
- data = (data >> 8) | (*(uchar *)cp << 8);
+ for (; cnt==0 && i<port_width; ++i, ++cp) {
+ data = (data << 8) | (*(uchar *)cp);
}
- if ((rc = write_word(info, wp, data)) != 0) {
+ if ((rc = write_data(info, wp, SWAP(data))) != 0) {
return (rc);
}
- wp += 2;
+ wp += port_width;
}
/*
* handle word aligned part
*/
- while (cnt >= 2) {
- data = *((vu_short*)src);
- if ((rc = write_word(info, wp, data)) != 0) {
+ count = 0;
+ while (cnt >= port_width) {
+ data = 0;
+ for (i=0; i<port_width; ++i) {
+ data = (data << 8) | *src++;
+ }
+ if ((rc = write_data(info, wp, SWAP(data))) != 0) {
return (rc);
}
- src += 2;
- wp += 2;
- cnt -= 2;
+ wp += port_width;
+ cnt -= port_width;
+ if (count++ > 0x800)
+ {
+ spin_wheel();
+ count = 0;
+ }
}
if (cnt == 0) {
- return ERR_OK;
+ return (0);
}
/*
* handle unaligned tail bytes
*/
data = 0;
- for (i=0, cp=wp; i<2 && cnt>0; ++i, ++cp) {
- data = (data >> 8) | (*src++ << 8);
+ for (i=0, cp=wp; i<port_width && cnt>0; ++i, ++cp) {
+ data = (data << 8) | *src++;
--cnt;
}
- for (; i<2; ++i, ++cp) {
- data = (data >> 8) | (*(uchar *)cp << 8);
+ for (; i<port_width; ++i, ++cp) {
+ data = (data << 8) | (*(uchar *)cp);
+ }
+
+ return (write_data(info, wp, SWAP(data)));
+}
+
+/*-----------------------------------------------------------------------
+ * Write a word or halfword to Flash, returns:
+ * 0 - OK
+ * 1 - write timeout
+ * 2 - Flash not erased
+ */
+static int write_data (flash_info_t *info, ulong dest, FPW data)
+{
+ FPWV *addr = (FPWV *)dest;
+ ulong status;
+ ulong start;
+ int flag;
+
+ /* Check if Flash is (sufficiently) erased */
+ if ((*addr & data) != data) {
+ printf("not erased at %08lx (%x)\n",(ulong)addr,*addr);
+ return (2);
+ }
+ /* Disable interrupts which might cause a timeout here */
+ flag = disable_interrupts();
+
+ *addr = (FPW)0x00400040; /* write setup */
+ *addr = data;
+
+ /* arm simple, non interrupt dependent timer */
+ reset_timer_masked();
+
+ /* wait while polling the status register */
+ while (((status = *addr) & (FPW)0x00800080) != (FPW)0x00800080) {
+ if (get_timer_masked() > CFG_FLASH_WRITE_TOUT) {
+ *addr = (FPW)0x00FF00FF; /* restore read mode */
+ return (1);
+ }
}
- return write_word(info, wp, data);
+ *addr = (FPW)0x00FF00FF; /* restore read mode */
+
+ return (0);
+}
+
+void inline
+spin_wheel(void)
+{
+ static int r=0,p=0;
+ static char w[] = "\\/-";
+
+ printf("\010%c", w[p]);
+ (++p == 3) ? (p = 0) : 0;
}
+
diff --git a/board/lubbock/lubbock.c b/board/lubbock/lubbock.c
index ba9b86b31..2487a4cba 100644
--- a/board/lubbock/lubbock.c
+++ b/board/lubbock/lubbock.c
@@ -47,7 +47,7 @@ int board_init (void)
/* adress of boot parameters */
gd->bd->bi_boot_params = 0xa0000100;
- return 1;
+ return 0;
}
int dram_init (void)
@@ -62,6 +62,6 @@ int dram_init (void)
gd->bd->bi_dram[2].size = PHYS_SDRAM_3_SIZE;
gd->bd->bi_dram[3].start = PHYS_SDRAM_4;
gd->bd->bi_dram[3].size = PHYS_SDRAM_4_SIZE;
- return PHYS_SDRAM_1_SIZE + PHYS_SDRAM_2_SIZE + PHYS_SDRAM_3_SIZE +
- PHYS_SDRAM_4_SIZE;
+
+ return 0;
}
diff --git a/board/lubbock/memsetup.S b/board/lubbock/memsetup.S
index c0278340a..5bbd85958 100644
--- a/board/lubbock/memsetup.S
+++ b/board/lubbock/memsetup.S
@@ -39,12 +39,16 @@ DRAM_SIZE: .long CFG_DRAM_SIZE
.endm
+/*
+ * Memory setup
+ */
+
.globl memsetup
memsetup:
mov r10, lr
- /* Set up GPIO pins first */
+ /* Set up GPIO pins first ----------------------------------------- */
ldr r0, =GPSR0
ldr r1, =CFG_GPSR0_VAL
@@ -106,562 +110,284 @@ memsetup:
ldr r1, =CFG_GAFR2_U_VAL
str r1, [r0]
- /* enable GPIO pins */
- ldr r0, =PSSR
+ ldr r0, =PSSR /* enable GPIO pins */
ldr r1, =CFG_PSSR_VAL
str r1, [r0]
- ldr r3, =MSC1 /* low - bank 2 Lubbock Registers / SRAM */
- ldr r2, =CFG_MSC1_VAL /* high - bank 3 Ethernet Controller */
- str r2, [r3] /* need to set MSC1 before trying to write to the HEX LEDs */
- ldr r2, [r3] /* need to read it back to make sure the value latches (see MSC section of manual) */
-
- ldr r1, =LED_BLANK
- mov r0, #0xFF
- str r0, [r1] /* turn on hex leds */
-
-loop:
- ldr r0, =0xB0070001
- ldr r1, =_LED
- str r0, [r1] /* hex display */
-
-/*********************************************************************
- Initlialize Memory Controller
- The sequence below is based on the recommended init steps detailed
- in the EAS, chapter 5 (Chapter 10, Operating Systems Developers Guide)
-
-
- pause for 200 uSecs- allow internal clocks to settle
- *Note: only need this if hard reset... doing it anyway for now
-*/
-
- @ ---- Wait 200 usec
- ldr r3, =OSCR @ reset the OS Timer Count to zero
+ /* ---------------------------------------------------------------- */
+ /* Enable memory interface */
+ /* */
+ /* The sequence below is based on the recommended init steps */
+ /* detailed in the Intel PXA250 Operating Systems Developers Guide, */
+ /* Chapter 10. */
+ /* ---------------------------------------------------------------- */
+
+ /* ---------------------------------------------------------------- */
+ /* Step 1: Wait for at least 200 microsedonds to allow internal */
+ /* clocks to settle. Only necessary after hard reset... */
+ /* FIXME: can be optimized later */
+ /* ---------------------------------------------------------------- */
+
+ ldr r3, =OSCR /* reset the OS Timer Count to zero */
mov r2, #0
str r2, [r3]
- ldr r4, =0x300 @ really 0x2E1 is about 200usec, so 0x300 should be plenty
+ ldr r4, =0x300 /* really 0x2E1 is about 200usec, */
+ /* so 0x300 should be plenty */
1:
ldr r2, [r3]
cmp r4, r2
bgt 1b
mem_init:
- @ get memory controller base address
- ldr r1, =MEMC_BASE
-@****************************************************************************
-@ Step 1
-@
+ ldr r1, =MEMC_BASE /* get memory controller base addr. */
- @ write msc0, read back to ensure data latches
- @
+ /* ---------------------------------------------------------------- */
+ /* Step 2a: Initialize Asynchronous static memory controller */
+ /* ---------------------------------------------------------------- */
+
+ /* MSC registers: timing, bus width, mem type */
+
+ /* MSC0: nCS(0,1) */
ldr r2, =CFG_MSC0_VAL
str r2, [r1, #MSC0_OFFSET]
- ldr r2, [r1, #MSC0_OFFSET]
-
- @ write msc1
+ ldr r2, [r1, #MSC0_OFFSET] /* read back to ensure */
+ /* that data latches */
+ /* MSC1: nCS(2,3) */
ldr r2, =CFG_MSC1_VAL
str r2, [r1, #MSC1_OFFSET]
ldr r2, [r1, #MSC1_OFFSET]
- @ write msc2
+ /* MSC2: nCS(4,5) */
ldr r2, =CFG_MSC2_VAL
str r2, [r1, #MSC2_OFFSET]
ldr r2, [r1, #MSC2_OFFSET]
- @ write mecr
+ /* ---------------------------------------------------------------- */
+ /* Step 2b: Initialize Card Interface */
+ /* ---------------------------------------------------------------- */
+
+ /* MECR: Memory Expansion Card Register */
ldr r2, =CFG_MECR_VAL
str r2, [r1, #MECR_OFFSET]
+ ldr r2, [r1, #MECR_OFFSET]
- @ write mcmem0
+ /* MCMEM0: Card Interface slot 0 timing */
ldr r2, =CFG_MCMEM0_VAL
str r2, [r1, #MCMEM0_OFFSET]
+ ldr r2, [r1, #MCMEM0_OFFSET]
- @ write mcmem1
+ /* MCMEM1: Card Interface slot 1 timing */
ldr r2, =CFG_MCMEM1_VAL
str r2, [r1, #MCMEM1_OFFSET]
+ ldr r2, [r1, #MCMEM1_OFFSET]
- @ write mcatt0
+ /* MCATT0: Card Interface Attribute Space Timing, slot 0 */
ldr r2, =CFG_MCATT0_VAL
str r2, [r1, #MCATT0_OFFSET]
+ ldr r2, [r1, #MCATT0_OFFSET]
- @ write mcatt1
+ /* MCATT1: Card Interface Attribute Space Timing, slot 1 */
ldr r2, =CFG_MCATT1_VAL
str r2, [r1, #MCATT1_OFFSET]
+ ldr r2, [r1, #MCATT1_OFFSET]
- @ write mcio0
+ /* MCIO0: Card Interface I/O Space Timing, slot 0 */
ldr r2, =CFG_MCIO0_VAL
str r2, [r1, #MCIO0_OFFSET]
+ ldr r2, [r1, #MCIO0_OFFSET]
- @ write mcio1
+ /* MCIO1: Card Interface I/O Space Timing, slot 1 */
ldr r2, =CFG_MCIO1_VAL
str r2, [r1, #MCIO1_OFFSET]
+ ldr r2, [r1, #MCIO1_OFFSET]
- @-------------------------------------------------------
- @ 3rd bullet, Step 1
- @
+ /* ---------------------------------------------------------------- */
+ /* Step 2c: Write FLYCNFG FIXME: what's that??? */
+ /* ---------------------------------------------------------------- */
- @ get the mdrefr settings
- ldr r3, =CFG_MDREFR_VAL_100
- @ extract DRI field (we need a valid DRI field)
- @
- ldr r2, =0xFFF
+ /* ---------------------------------------------------------------- */
+ /* Step 2d: Initialize Timing for Sync Memory (SDCLK0) */
+ /* ---------------------------------------------------------------- */
- @ valid DRI field in r3
- @
- and r3, r3, r2
+ /* Before accessing MDREFR we need a valid DRI field, so we set */
+ /* this to power on defaults + DRI field. */
- @ get the reset state of MDREFR
- @
+ ldr r3, =CFG_MDREFR_VAL
+ ldr r2, =0xFFF
+ and r3, r3, r2
+ ldr r4, =0x03ca4000
+ orr r4, r4, r3
+ str r4, [r1, #MDREFR_OFFSET] /* write back MDREFR */
ldr r4, [r1, #MDREFR_OFFSET]
- @ clear the DRI field
- @
- bic r4, r4, r2
-
- @ insert the valid DRI field loaded above
- @
- orr r4, r4, r3
-
- @ write back mdrefr
- @
- str r4, [r1, #MDREFR_OFFSET]
-
- @ *Note: preserve the mdrefr value in r4 *
-
-@****************************************************************************
-@ Step 2
-@
- /* This should be for SRAM, why is it commented out??? */
-
- @ fetch sxcnfg value
- @
- @ldr r2, =0
- @ write back sxcnfg
- @str r2, [r1, #SXCNFG_OFFSET]
-
-/* @if sxcnfg=0, don't program for synch-static memory */
- @cmp r2, #0
- @beq 1f
-
- @program sxmrs
- @ldr r2, =SXMRS_SETTINGS
- @str r2, [r1, #SXMRS_OFFSET]
-
-
-@****************************************************************************
-@ Step 3
-@
-
- @ Assumes previous mdrefr value in r4, if not then read current mdrefr
-
- @ clear the free-running clock bits
- @ (clear K0Free, K1Free, K2Free
- @
- bic r4, r4, #(0x00800000 | 0x01000000 | 0x02000000)
-
- @ set K1RUN if bank 0 installed
- @
- orr r4, r4, #0x00010000
-
-
-
-#ifdef THIS
-@<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<
-@<!<!<!<!<!<!<!<!<!<!<! Begin INSERT 1 <!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<
- @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
- @ Lubbock: Allow the user to select the {T/R/M} with predetermined
- @ SDCLK. Based on Table 3-1 in PXA250 and PXA210 Dev Man.
- @
- @ * = Must set MDREFR.K1DB2 to halve the MemClk for desired SDCLK[1]
- @
- @ S25, S26 used to provide all 400 MHz BIN values for Cotulla (0,0 - 1,3)
- @ S25, S26 used to provide all 200 MHz BIN values for Sabinal
- @
- @ S23: Force the halving of MemClk when deriving SDCLK[1]
- @ DOT: no override !DOT: halve (if not already forced half)
-/* @ *For certain MemClks, SDCLK's derivation is forced to be halved */
- @
- @ S24: Run/Turbo.
- @ DOT: Run mode !DOT: Turbo mode
- @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
-
- @
- @ Allow the user to control K1DB2 where applicable
- @
- @ Get the value of S23: @ 1 = DOT (unity), 0 = !DOT (halve it)
- @
- @ DOT: set K1DB2 (SDCLD = MemClk)
- @ !DOT: clear K1DB2 (SDCLK = MemClk/2)
- @
- @ldr r2, =FPGA_REGS_BASE_PHYSICAL
-
- bl GET_S23 @ r3, r2 @ get the value of S23 in R0, i put the base adx of fpga in r3
-
- cmp r3, #0x0 @ is !DOT?
- orreq r4, r4, #0x00020000 @ SDClk[1] = MemClk/2
- bicne r4, r4, #0x00020000 @ SDClk[1] = MemClk
-
- @
- @ Next, we need to look for S25,S26 selections that necessitate the
- @ halving of MemClk to derive SDCLK[1]: (S25,S26)={03-0C, 10-13}
- @ Override above S23-based selection accordingly.
- @
- ldr r2, =FPGA_REGS_BASE_PHYSICAL
- bl GET_S25 @ r0, r2
- @ get the value of S25 in R0, i put the base adx of fpga in r2
-
-
-
- ldr r2, =FPGA_REGS_BASE_PHYSICAL
- BL GET_S26 @ r3, r2
- @ get the value of S26 in R1, i put the base adx of fpga in r2
-
- orr r0, r0, r3 @ concatenate S25 & S26 vals
- and r0, r0, #0xFF
-
- @ Set K1DB2 for the frequencies that require it
- @
- cmp r0, #0x03
- cmpne r0, #0x04
- cmpne r0, #0x05
- cmpne r0, #0x06
- cmpne r0, #0x07
- cmpne r0, #0x08
- cmpne r0, #0x09
- cmpne r0, #0x0A
- cmpne r0, #0x0B
- cmpne r0, #0x0C
- cmpne r0, #0x10
- cmpne r0, #0x11
- cmpne r0, #0x12
- cmpne r0, #0x13
- orreq r4, r4, #0x00020000 @ SDCLK[1] = (MemClk)/2 for 03 - 0C @ 10 - 13
-
- @
- @ *Must make MSC0&1 adjustments now for MEMClks > 100MHz.
- @
- @ Adjust MSC0 for MemClks > 100 MHz
- @
- ldreq r0, [r1, #MSC0_OFFSET]
- ldreq r3, =0x7F007F00
- biceq r0, r0, r3 @ clear MSC0[14:12, 11:8] (RRR, RDN)
- ldreq r3, =0x46004600
- orreq r0, r0, r3 @ set MSC0[14, 10:9] (doubling RRR, RDN)
- streq r0, [r1, #MSC0_OFFSET]
- ldreq r0, [r1, #MSC0_OFFSET] @ read it back to ensure that the data latches
-
- @
- @ Adjust MSC1.LH for MemClks > 100 MHz
- @
- ldreq r0, [r1, #MSC1_OFFSET]
- ldreq r3, =0x7FF0
- biceq r0, r0, r3 @ clear MSC1[14:12, 11:8, 7:4] (RRR, RDN, RDF)
- ldreq r3, =0x4880
- orreq r0, r0, r3 @ set MSC1[14, 11, 7] (doubling RRR, RDN, RDF)
- streq r0, [r1, #MSC1_OFFSET]
- ldreq r0, [r1, #MSC1_OFFSET] @ read it back to ensure that the data latches
-
- @ @
- @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
-#endif
+ /* Note: preserve the mdrefr value in r4 */
-@<!<!<!<!<!<!<!<!<!<!<! End INSERT 1 <!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<
-@<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<!<
+ /* ---------------------------------------------------------------- */
+ /* Step 3: Initialize Synchronous Static Memory (Flash/Peripherals) */
+ /* ---------------------------------------------------------------- */
- @ write back mdrefr
- @
- str r4, [r1, #MDREFR_OFFSET]
- ldr r4, [r1, #MDREFR_OFFSET]
+ /* Initialize SXCNFG register. Assert the enable bits */
- @ deassert SLFRSH
- @
- bic r4, r4, #0x00400000
+ /* Write SXMRS to cause an MRS command to all enabled banks of */
+ /* synchronous static memory. Note that SXLCR need not be written */
+ /* at this time. */
- @ write back mdrefr
- @
- str r4, [r1, #MDREFR_OFFSET]
+ /* FIXME: we use async mode for now */
- @ assert E1PIN
- @
- orr r4, r4, #0x00008000
- @ write back mdrefr
- @
- str r4, [r1, #MDREFR_OFFSET]
+ /* ---------------------------------------------------------------- */
+ /* Step 4: Initialize SDRAM */
+ /* ---------------------------------------------------------------- */
+
+ /* set MDREFR according to user define with exception of a few bits */
+
+ ldr r4, =CFG_MDREFR_VAL
+ orr r4, r4, #(MDREFR_SLFRSH)
+ bic r4, r4, #(MDREFR_E1PIN|MDREFR_E0PIN)
+ str r4, [r1, #MDREFR_OFFSET] /* write back MDREFR */
ldr r4, [r1, #MDREFR_OFFSET]
- nop
- nop
+ /* Step 4b: de-assert MDREFR:SLFRSH. */
-@****************************************************************************
-@ Step 4
-@
+ bic r4, r4, #(MDREFR_SLFRSH)
+ str r4, [r1, #MDREFR_OFFSET] /* write back MDREFR */
+ ldr r4, [r1, #MDREFR_OFFSET]
- @ fetch platform value of mdcnfg
- @
- ldr r2, =CFG_MDCNFG_VAL
- @ disable all sdram banks
- @
- bic r2, r2, #(MDCNFG_DE0 | MDCNFG_DE1)
- bic r2, r2, #(MDCNFG_DE2 | MDCNFG_DE3)
+ /* Step 4c: assert MDREFR:E1PIN and E0PIO as desired */
- @ program banks 0/1 for bus width
- @
- bic r2, r2, #MDCNFG_DWID0 @0=32-bit
+ ldr r4, =CFG_MDREFR_VAL
+ str r4, [r1, #MDREFR_OFFSET] /* write back MDREFR */
+ ldr r4, [r1, #MDREFR_OFFSET]
- @ write initial value of mdcnfg, w/o enabling sdram banks
- @
- str r2, [r1, #MDCNFG_OFFSET]
+ /* Step 4d: write MDCNFG with MDCNFG:DEx deasserted (set to 0), to */
+ /* configure but not enable each SDRAM partition pair. */
-@ ****************************************************************************
-@ Step 5
-@
+ ldr r4, =CFG_MDCNFG_VAL
+ bic r4, r4, #(MDCNFG_DE0|MDCNFG_DE1)
- @ pause for 200 uSecs
- @
- ldr r3, =OSCR @reset the OS Timer Count to zero
+ str r4, [r1, #MDCNFG_OFFSET] /* write back MDCNFG */
+ ldr r4, [r1, #MDCNFG_OFFSET]
+
+
+ /* Step 4e: Wait for the clock to the SDRAMs to stabilize, */
+ /* 100..200 µsec. */
+
+ ldr r3, =OSCR /* reset the OS Timer Count to zero */
mov r2, #0
str r2, [r3]
- ldr r4, =0x300 @really 0x2E1 is about 200usec, so 0x300 should be plenty
+ ldr r4, =0x300 /* really 0x2E1 is about 200usec, */
+ /* so 0x300 should be plenty */
1:
ldr r2, [r3]
cmp r4, r2
bgt 1b
-@****************************************************************************
-@ Step 6
-@
-
- mov r0, #0x78 @turn everything off
- mcr p15, 0, r0, c1, c0, 0 @(caches off, MMU off, etc.)
-
+ /* Step 4f: Trigger a number (usually 8) refresh cycles by */
+ /* attempting non-burst read or write accesses to disabled */
+ /* SDRAM, as commonly specified in the power up sequence */
+ /* documented in SDRAM data sheets. The address(es) used */
+ /* for this purpose must not be cacheable. */
-@ ****************************************************************************
-@ Step 7
-@
- @ Access memory *not yet enabled* for CBR refresh cycles (8)
- @ - CBR is generated for all banks
+ ldr r3, =CFG_DRAM_BASE
+ str r2, [r3]
+ str r2, [r3]
+ str r2, [r3]
+ str r2, [r3]
+ str r2, [r3]
+ str r2, [r3]
+ str r2, [r3]
+ str r2, [r3]
- ldr r2, =CFG_DRAM_BASE
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
+ /* Step 4g: Write MDCNFG with enable bits asserted */
+ /* (MDCNFG:DEx set to 1). */
-@ ****************************************************************************
-@ Step 8: NOP (enable dcache if you wanna... we dont)
-@
-
-
-@ ****************************************************************************
-@ Step 9
-@
-
-
- @get memory controller base address
- @
- ldr r1, =MEMC_BASE
-
- @fetch current mdcnfg value
- @
ldr r3, [r1, #MDCNFG_OFFSET]
-
- @enable sdram bank 0 if installed (must do for any populated bank)
- @
- orr r3, r3, #MDCNFG_DE0
-
- @write back mdcnfg, enabling the sdram bank(s)
- @
+ orr r3, r3, #(MDCNFG_DE0|MDCNFG_DE1)
str r3, [r1, #MDCNFG_OFFSET]
+ /* Step 4h: Write MDMRS. */
-@****************************************************************************
-@ Step 10
-@
-
- @ write mdmrs
- @
ldr r2, =CFG_MDMRS_VAL
str r2, [r1, #MDMRS_OFFSET]
-@****************************************************************************
-@ Step 11: Final Step
-@
+ /* We are finished with Intel's memory controller initialisation */
+
-@INITINTC
- @********************************************************************
- @ Disable (mask) all interrupts at the interrupt controller
- @
+ /* ---------------------------------------------------------------- */
+ /* Disable (mask) all interrupts at interrupt controller */
+ /* ---------------------------------------------------------------- */
- @ clear the interrupt level register (use IRQ, not FIQ)
- @
- mov r1, #0
+initirqs:
+
+ mov r1, #0 /* clear int. level register (IRQ, not FIQ) */
ldr r2, =ICLR
str r1, [r2]
- @ mask all interrupts at the controller
- @
- ldr r2, =ICMR
+ ldr r2, =ICMR /* mask all interrupts at the controller */
str r1, [r2]
-@INITCLKS
- @ ********************************************************************
- @ Disable the peripheral clocks, and set the core clock
- @ frequency (hard-coding at 398.12MHz for now).
- @
+ /* ---------------------------------------------------------------- */
+ /* Clock initialisation */
+ /* ---------------------------------------------------------------- */
+
+initclks:
+
+ /* Disable the peripheral clocks, and set the core clock frequency */
+ /* (hard-coding at 398.12MHz for now). */
- @ Turn Off ALL on-chip peripheral clocks for re-configuration
- @ *Note: See label 'ENABLECLKS' for the re-enabling
- @
+ /* Turn Off ALL on-chip peripheral clocks for re-configuration */
+ /* Note: See label 'ENABLECLKS' for the re-enabling */
ldr r1, =CKEN
mov r2, #0
str r2, [r1]
- @ default value in case no valid rotary switch setting is found
- ldr r2, =(CCCR_L27 | CCCR_M2 | CCCR_N10) @ DEFAULT: {200/200/100}
+ /* default value in case no valid rotary switch setting is found */
+ ldr r2, =(CCCR_L27|CCCR_M2|CCCR_N10) /* DEFAULT: {200/200/100} */
-
- @... and write the core clock config register
- @
+ /* ... and write the core clock config register */
ldr r1, =CCCR
str r2, [r1]
-/* @ enable the 32Khz oscillator for RTC and PowerManager
- @
+#ifdef RTC
+ /* enable the 32Khz oscillator for RTC and PowerManager */
+
ldr r1, =OSCC
mov r2, #OSCC_OON
str r2, [r1]
-
- @ NOTE: spin here until OSCC.OOK get set,
- @ meaning the PLL has settled.
- @
+ /* NOTE: spin here until OSCC.OOK get set, meaning the PLL */
+ /* has settled. */
60:
ldr r2, [r1]
ands r2, r2, #1
beq 60b
-*/
-
-@OSCC_OON_DONE
-
-
-#ifdef A0_COTULLA
- @****************************************************************************
- @ !!! Take care of A0 Errata Sighting #4 --
- @ after a frequency change, the memory controller must be restarted
- @
-
- @ get memory controller base address
- ldr r1, =MEMC_BASE
-
- @ get the current state of MDREFR
- @
- ldr r2, [r1, #MDREFR_OFFSET]
-
- @ clear E0PIN, E1PIN
- @
- bic r3, r2, #(MDREFR_E0PIN | MDREFR_E1PIN)
-
- @ write MDREFR with E0PIN, E1PIN cleared (disable sdclk[0,1])
- @
- str r3, [r1, #MDREFR_OFFSET]
-
- @ then write MDREFR with E0PIN, E1PIN set (enable sdclk[0,1])
- @
- str r2, [r1, #MDREFR_OFFSET]
-
- @ get the current state of MDCNFG
- @
- ldr r3, [r1, #MDCNFG_OFFSET]
-
- @ disable all SDRAM banks
- @
- bic r3, r3, #(MDCNFG_DE0 | MDCNFG_DE1)
- bic r3, r3, #(MDCNFG_DE2 | MDCNFG_DE3)
-
- @ write back MDCNFG
- @
- ldr r3, [r1, #MDCNFG_OFFSET]
-
- @ Access memory not yet enabled for CBR refresh cycles (8)
- @ - CBR is generated for *all* banks
- ldr r2, =CFG_DRAM_BASE
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
- str r2, [r2]
-
- @ fetch current mdcnfg value
- @
- ldr r3, [r1, #MDCNFG_OFFSET]
-
- @ enable sdram bank 0 if installed
- @
- orr r3, r3, #MDCNFG_DE0
-
- @ write back mdcnfg, enabling the sdram bank(s)
- @
- str r3, [r1, #MDCNFG_OFFSET]
-
- @ write mdmrs
- @
- ldr r2, =CFG_MDMRS_VAL
- str r2, [r1, #MDMRS_OFFSET]
-
-
-
- /* @ errata: don't enable auto power-down */
- @ get current value of mdrefr
- @ldr r3, [r1, #MDREFR_OFFSET]
- @ enable auto-power down
- @orr r3, r3, #MDREFR_APD
- @write back mdrefr
- @str r3, [r1, #MDREFR_OFFSET]
-
-#endif A0_Cotulla
-
-
- ldr r0, =0x000C0dE3
- ldr r1, =_LED
- str r0, [r1] /* hex display */
-
-@ ^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%
-@ ^%^%^%^%^%^%^%^%^% above could be replaced by prememLLI ^%^%^%^%^%^%^%^%^%
-@ ^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%^%
+#endif
+ /* ---------------------------------------------------------------- */
+ /* */
+ /* ---------------------------------------------------------------- */
/* Save SDRAM size */
ldr r1, =DRAM_SIZE
str r8, [r1]
- ldr r0, =0xC0DE0006
- ldr r1, =_LED
- str r0, [r1] /* hex display */
-
- /* Interrupt init */
- /* Mask all interrupts */
+ /* Interrupt init: Mask all interrupts */
ldr r0, =ICMR /* enable no sources */
mov r1, #0
str r1, [r0]
+ /* FIXME */
+
#define NODEBUG
#ifdef NODEBUG
/*Disable software and data breakpoints */
@@ -676,74 +402,11 @@ mem_init:
#endif
- ldr r0, =0xBEEF001D
- ldr r1, =_LED
- str r0, [r1] /* hex display */
+ /* ---------------------------------------------------------------- */
+ /* End memsetup */
+ /* ---------------------------------------------------------------- */
- mov pc, r10
-
-@ End memsetup
-
-@ %%%%%%%%%%% Useful subroutines
-GET_S23:
- @ This macro will read S23 and return its value in r3
- @ r2 contains the base address of the Lubbock user registers
- ldr r2, =FPGA_REGS_BASE_PHYSICAL
-
- /*@ read S23's value */
- ldr r3, [r2, #USER_SWITCHES_OFFSET]
-
- @ mask out irrelevant bits
- and r3, r3, #0x200
-
- @ get bit into position 0
- mov r3, r3, LSR #9
-
- mov pc, lr
-@ End GET_S23
-
-
-GET_S24:
- @ This macro will read S24 and return its value in r0
- @ r2 contains the base address of the Lubbock user registers
- ldr r2, =FPGA_REGS_BASE_PHYSICAL
-
- /*@ read S24's value */
- ldr r0, [r2, #USER_SWITCHES_OFFSET]
-
- @ mask out irrelevant bits
- and r0, r0, #0x100
-
- @ get bit into position 0
- mov r0, r0, LSR #8
+endmemsetup:
mov pc, lr
-@ End GET_S23
-
-
-GET_S25:
- @ This macro will read rotary S25 and return its value in r0
- @ r2 contains the base address of the Lubbock user registers
- @ read the user switches register
- ldr r0, [r2, #USER_SWITCHES_OFFSET]
-
- @ mask out irrelevant bits
- and r0, r0, #0xF0
-
- mov pc, lr
-@ End subroutine
-
-
-GET_S26:
- @ This macro will read rotary S26 and return its value in r3
- @ r2 contains the base address of the Lubbock user registers
- @ read the user switches register
- ldr r3, [r2, #USER_SWITCHES_OFFSET]
-
- @ mask out irrelevant bits
- and r3, r3, #0x0F
-
- mov pc, lr
-@ End subroutine GET_S26
-