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-rw-r--r--cpu/xscale/start.S168
1 files changed, 93 insertions, 75 deletions
diff --git a/cpu/xscale/start.S b/cpu/xscale/start.S
index 6cc7c43..cc24c30 100644
--- a/cpu/xscale/start.S
+++ b/cpu/xscale/start.S
@@ -17,7 +17,7 @@
*
* 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
+ * 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
@@ -32,7 +32,7 @@
#include <version.h>
.globl _start
-_start: b reset
+_start: b reset
ldr pc, _undefined_instruction
ldr pc, _software_interrupt
ldr pc, _prefetch_abort
@@ -41,7 +41,7 @@ _start: b reset
ldr pc, _irq
ldr pc, _fiq
-_undefined_instruction: .word undefined_instruction
+_undefined_instruction: .word undefined_instruction
_software_interrupt: .word software_interrupt
_prefetch_abort: .word prefetch_abort
_data_abort: .word data_abort
@@ -112,20 +112,20 @@ FIQ_STACK_START:
/****************************************************************************/
-/* */
-/* the actual reset code */
-/* */
+/* */
+/* the actual reset code */
+/* */
/****************************************************************************/
reset:
- mrs r0,cpsr /* set the cpu to SVC32 mode */
- bic r0,r0,#0x1f /* (superviser mode, M=10011) */
+ mrs r0,cpsr /* set the cpu to SVC32 mode */
+ bic r0,r0,#0x1f /* (superviser mode, M=10011) */
orr r0,r0,#0x13
msr cpsr,r0
- bl cpu_init_crit /* we do sys-critical inits */
+ bl cpu_init_crit /* we do sys-critical inits */
-relocate: /* relocate U-Boot to RAM */
+relocate: /* relocate U-Boot to RAM */
adr r0, _start /* r0 <- current position of code */
ldr r2, _armboot_start
ldr r3, _armboot_end
@@ -139,41 +139,47 @@ copy_loop:
cmp r0, r2 /* until source end addreee [r2] */
ble copy_loop
- /* Set up the stack */
+ /* Set up the stack */
ldr r0, _uboot_reloc /* upper 128 KiB: relocated uboot */
- sub r0, r0, #CFG_MALLOC_LEN /* malloc area */
- /* FIXME: bdinfo should be here */
+ sub r0, r0, #CFG_MALLOC_LEN /* malloc area */
+ /* FIXME: bdinfo should be here */
sub sp, r0, #12 /* leave 3 words for abort-stack */
ldr pc, _start_armboot
-_start_armboot: .word start_armboot
+_start_armboot: .word start_armboot
/****************************************************************************/
-/* */
-/* CPU_init_critical registers */
-/* */
-/* - setup important registers */
-/* - setup memory timing */
-/* */
+/* */
+/* CPU_init_critical registers */
+/* */
+/* - setup important registers */
+/* - setup memory timing */
+/* */
/****************************************************************************/
- /* Interrupt-Controller base address */
+ /* Interrupt-Controller base address */
IC_BASE: .word 0x40d00000
#define ICMR 0x04
/* Reset-Controller */
-RST_BASE: .word 0x40f00030
+RST_BASE: .word 0x40f00030
#define RCSR 0x00
+ /* Operating System Timer */
+OSTIMER_BASE: .word 0x40a00000
+#define OSMR3 0x0C
+#define OSCR 0x10
+#define OWER 0x18
+#define OIER 0x1C
- /* Clock Manager Registers */
-CC_BASE: .word 0x41300000
-#define CCCR 0x00
-cpuspeed: .word CFG_CPUSPEED
+ /* Clock Manager Registers */
+CC_BASE: .word 0x41300000
+#define CCCR 0x00
+cpuspeed: .word CFG_CPUSPEED
- /* RS: ??? */
+ /* RS: ??? */
.macro CPWAIT
mrc p15,0,r0,c2,c0,0
mov r0,r0
@@ -183,7 +189,7 @@ cpuspeed: .word CFG_CPUSPEED
cpu_init_crit:
- /* mask all IRQs */
+ /* mask all IRQs */
ldr r0, IC_BASE
mov r1, #0x00
str r1, [r0, #ICMR]
@@ -204,20 +210,20 @@ cpu_init_crit:
/* Memory interfaces are working. Disable MMU and enable I-cache. */
- ldr r0, =0x2001 /* enable access to all coproc. */
+ ldr r0, =0x2001 /* enable access to all coproc. */
mcr p15, 0, r0, c15, c1, 0
CPWAIT
mcr p15, 0, r0, c7, c10, 4 /* drain the write & fill buffers */
CPWAIT
- mcr p15, 0, r0, c7, c7, 0 /* flush Icache, Dcache and BTB */
+ mcr p15, 0, r0, c7, c7, 0 /* flush Icache, Dcache and BTB */
CPWAIT
mcr p15, 0, r0, c8, c7, 0 /* flush instuction and data TLBs */
CPWAIT
- /* Enable the Icache */
+ /* Enable the Icache */
/*
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #0x1800
@@ -228,12 +234,12 @@ cpu_init_crit:
/****************************************************************************/
-/* */
-/* Interrupt handling */
-/* */
+/* */
+/* Interrupt handling */
+/* */
/****************************************************************************/
-/* IRQ stack frame */
+/* IRQ stack frame */
#define S_FRAME_SIZE 72
@@ -259,38 +265,38 @@ cpu_init_crit:
#define MODE_SVC 0x13
- /* use bad_save_user_regs for abort/prefetch/undef/swi ... */
+ /* use bad_save_user_regs for abort/prefetch/undef/swi ... */
.macro bad_save_user_regs
sub sp, sp, #S_FRAME_SIZE
- stmia sp, {r0 - r12} /* Calling r0-r12 */
- add r8, sp, #S_PC
+ stmia sp, {r0 - r12} /* Calling r0-r12 */
+ add r8, sp, #S_PC
ldr r2, _armboot_end
add r2, r2, #CONFIG_STACKSIZE
sub r2, r2, #8
- ldmia r2, {r2 - r4} /* get pc, cpsr, old_r0 */
- add r0, sp, #S_FRAME_SIZE /* restore sp_SVC */
+ ldmia r2, {r2 - r4} /* get pc, cpsr, old_r0 */
+ add r0, sp, #S_FRAME_SIZE /* restore sp_SVC */
add r5, sp, #S_SP
mov r1, lr
- stmia r5, {r0 - r4} /* save sp_SVC, lr_SVC, pc, cpsr, old_r */
+ stmia r5, {r0 - r4} /* save sp_SVC, lr_SVC, pc, cpsr, old_r */
mov r0, sp
.endm
- /* use irq_save_user_regs / irq_restore_user_regs for */
- /* IRQ/FIQ handling */
+ /* use irq_save_user_regs / irq_restore_user_regs for */
+ /* IRQ/FIQ handling */
.macro irq_save_user_regs
sub sp, sp, #S_FRAME_SIZE
- stmia sp, {r0 - r12} /* Calling r0-r12 */
- add r8, sp, #S_PC
- stmdb r8, {sp, lr}^ /* Calling SP, LR */
- str lr, [r8, #0] /* Save calling PC */
- mrs r6, spsr
- str r6, [r8, #4] /* Save CPSR */
- str r0, [r8, #8] /* Save OLD_R0 */
+ stmia sp, {r0 - r12} /* Calling r0-r12 */
+ add r8, sp, #S_PC
+ stmdb r8, {sp, lr}^ /* Calling SP, LR */
+ str lr, [r8, #0] /* Save calling PC */
+ mrs r6, spsr
+ str r6, [r8, #4] /* Save CPSR */
+ str r0, [r8, #8] /* Save OLD_R0 */
mov r0, sp
.endm
@@ -309,7 +315,7 @@ cpu_init_crit:
str lr, [r13] @ save caller lr / spsr
mrs lr, spsr
- str lr, [r13, #4]
+ str lr, [r13, #4]
mov r13, #MODE_SVC @ prepare SVC-Mode
msr spsr_c, r13
@@ -327,40 +333,40 @@ cpu_init_crit:
/****************************************************************************/
-/* */
-/* exception handlers */
-/* */
+/* */
+/* exception handlers */
+/* */
/****************************************************************************/
- .align 5
+ .align 5
undefined_instruction:
get_bad_stack
bad_save_user_regs
- bl do_undefined_instruction
+ bl do_undefined_instruction
.align 5
software_interrupt:
get_bad_stack
bad_save_user_regs
- bl do_software_interrupt
+ bl do_software_interrupt
.align 5
prefetch_abort:
get_bad_stack
bad_save_user_regs
- bl do_prefetch_abort
+ bl do_prefetch_abort
.align 5
data_abort:
get_bad_stack
bad_save_user_regs
- bl do_data_abort
+ bl do_data_abort
.align 5
not_used:
get_bad_stack
bad_save_user_regs
- bl do_not_used
+ bl do_not_used
#ifdef CONFIG_USE_IRQ
@@ -368,14 +374,14 @@ not_used:
irq:
get_irq_stack
irq_save_user_regs
- bl do_irq
+ bl do_irq
irq_restore_user_regs
.align 5
fiq:
get_fiq_stack
irq_save_user_regs /* someone ought to write a more */
- bl do_fiq /* effiction fiq_save_user_regs */
+ bl do_fiq /* effiction fiq_save_user_regs */
irq_restore_user_regs
#else
@@ -384,28 +390,40 @@ fiq:
irq:
get_bad_stack
bad_save_user_regs
- bl do_irq
+ bl do_irq
.align 5
fiq:
get_bad_stack
bad_save_user_regs
- bl do_fiq
+ bl do_fiq
#endif
-/*
- * FIXME How do we reset??? Watchdog timeout??
- */
+/************************************************************************/
+/* */
+/* Reset function: the PXA250 has no reset function, so we have to */
+/* perform a watchdog timeout to cause a reset. */
+/* */
+/************************************************************************/
.align 5
.globl reset_cpu
reset_cpu:
- /*
- ldr r0, RST_BASE
- mov r1, #0x0 @ set bit 3-0 ...
- str r1, [r0, #RCSR] @ ... to clear in RCSR
- mov r1, #0x1
- str r1, [r0, #RCSR] @ and perform reset
- */
- b reset_cpu @ silly, but repeat endlessly
+ /* We set OWE:WME (watchdog enable) and wait until timeout happens */
+
+ ldr r0, OSTIMER_BASE
+ ldr r1, [r0, #OWER]
+ orr r1, r1, #0x0001 /* bit0: WME */
+ str r1, [r0, #OWER]
+
+ /* OS timer does only wrap every 1165 seconds, so we have to set */
+ /* the match register as well. */
+
+ ldr r1, [r0, #OSCR] /* read OS timer */
+ add r1, r1, #0x800 /* let OSMR3 match after */
+ add r1, r1, #0x800 /* 4096*(1/3.6864MHz)=1ms */
+ str r1, [r0, #OSMR3]
+
+reset_endless:
+ b reset_endless