diff options
Diffstat (limited to 'cpu/xscale')
| -rw-r--r-- | cpu/xscale/start.S | 168 |
1 files changed, 93 insertions, 75 deletions
diff --git a/cpu/xscale/start.S b/cpu/xscale/start.S index 6cc7c43dbd0..cc24c30bfa4 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 |