diff options
Diffstat (limited to 'openpicc/os/boot/boot.s')
| -rw-r--r-- | openpicc/os/boot/boot.s | 93 |
1 files changed, 91 insertions, 2 deletions
diff --git a/openpicc/os/boot/boot.s b/openpicc/os/boot/boot.s index 6bd5db2..cbd9be7 100644 --- a/openpicc/os/boot/boot.s +++ b/openpicc/os/boot/boot.s @@ -23,7 +23,7 @@ /* Stack Sizes */ .set UND_STACK_SIZE, 0x00000004 .set ABT_STACK_SIZE, 0x00000004 - .set FIQ_STACK_SIZE, 0x00000004 + .set FIQ_STACK_SIZE, 0x00000400 .set IRQ_STACK_SIZE, 0X00000400 .set SVC_STACK_SIZE, 0x00000400 @@ -39,6 +39,20 @@ .equ I_BIT, 0x80 /* when I bit is set, IRQ is disabled */ .equ F_BIT, 0x40 /* when F bit is set, FIQ is disabled */ +.equ AT91C_BASE_AIC, (0xFFFFF000) +.equ AT91C_BASE_PIOA, 0xFFFFF400 +.equ AT91C_BASE_TC0, 0xFFFA0000 +.equ AT91C_TC_SWTRG, (1 << 2) +.equ PIO_DATA, (1 << 27) +.equ PIOA_SODR, 0x30 +.equ PIOA_CODR, 0x34 +.equ PIOA_PDSR, 0x3c +.equ PIOA_IDR, 0x44 +.equ PIOA_ISR, 0x4c +.equ TC_CCR, 0x00 +.equ AIC_EOICR, (304) +/*.equ PIO_LED1, (1 << 25)*/ +.equ PIO_LED1, (1 << 12) start: _start: @@ -55,6 +69,11 @@ _mainCRTStartup: mov sp, r0 sub r0, r0, #ABT_STACK_SIZE msr CPSR_c, #MODE_FIQ|I_BIT|F_BIT /* FIQ Mode */ + /* Preload registers for FIQ handler */ + ldr r10, =AT91C_BASE_PIOA + ldr r12, =AT91C_BASE_TC0 + ldr r8, =AT91C_BASE_AIC + mov r9, #AT91C_TC_SWTRG mov sp, r0 sub r0, r0, #FIQ_STACK_SIZE msr CPSR_c, #MODE_IRQ|I_BIT|F_BIT /* IRQ Mode */ @@ -147,7 +166,7 @@ endless_loop: ldr pc, _dabt /* data abort - _dabt */ nop /* reserved */ ldr pc, [pc,#-0xF20] /* IRQ - read the AIC */ - ldr pc, _fiq /* FIQ - _fiq */ + ldr pc, [pc,#-0xF20] /* FIQ - read the AIC */ _undf: .word __undf /* undefined */ _swi: .word swi_handler /* SWI */ @@ -159,3 +178,73 @@ __undf: b . /* undefined */ __pabt: b . /* program abort */ __dabt: b . /* data abort */ __fiq: b . /* FIQ */ + +/* Following is from openpcd/firmware/src/start/Cstartup_app.S */ +#define LED_TRIGGER +/*#define CALL_PIO_IRQ_DEMUX*/ + + .text + .arm + .section .fastrun, "ax" + + .global fiq_handler + .func fiq_handler +fiq_handler: + /* code that uses pre-initialized FIQ reg */ + /* r8 AT91C_BASE_AIC (dfu init) + r9 AT91C_TC_SWTRG + r10 AT91C_BASE_PIOA + r11 tmp + r12 AT91C_BASE_TC0 + r13 stack + r14 lr + */ + + ldr r8, [r10, #PIOA_ISR] + tst r8, #PIO_DATA /* check for PIO_DATA change */ + ldrne r11, [r10, #PIOA_PDSR] + tstne r11, #PIO_DATA /* check for PIO_DATA == 1 */ + strne r9, [r12, #TC_CCR] /* software trigger */ +#ifdef LED_TRIGGER + movne r11, #PIO_LED1 + strne r11, [r10, #PIOA_CODR] /* enable LED */ +#endif + +#if 1 + movne r11, #PIO_DATA + strne r11, [r10, #PIOA_IDR] /* disable further PIO_DATA FIQ */ +#endif + + /*- Mark the End of Interrupt on the AIC */ + ldr r11, =AT91C_BASE_AIC + str r11, [r11, #AIC_EOICR] + +#ifdef LED_TRIGGER + mov r11, #PIO_LED1 + str r11, [r10, #PIOA_SODR] /* disable LED */ +#endif + +#ifdef CALL_PIO_IRQ_DEMUX + /* push r0, r1-r3, r12, r14 onto FIQ stack */ + /*stmfd sp!, { r0-r3, r12, lr} + mov r0, r8*/ + + /* enable interrupts while handling demux */ + /* enable interrupts while handling demux */ + /* msr CPSR_c, #F_BIT | ARM_MODE_SVC */ + + /* Call C function, give PIOA_ISR as argument */ + /*ldr r11, =__pio_irq_demux + mov r14, pc + bx r11*/ + + /* msr CPSR_c, #I_BIT | F_BIT | ARM_MODE_FIQ */ + /*ldmia sp!, { r0-r3, r12, lr }*/ +#endif + + /*- Restore the Program Counter using the LR_fiq directly in the PC */ + subs pc, lr, #4 + + .size fiq_handler, . - fiq_handler + .endfunc + .end |