diff options
Diffstat (limited to 'openpicc/os/boot/Cstartup_app.S')
| -rw-r--r-- | openpicc/os/boot/Cstartup_app.S | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/openpicc/os/boot/Cstartup_app.S b/openpicc/os/boot/Cstartup_app.S new file mode 100644 index 0000000..448cc93 --- /dev/null +++ b/openpicc/os/boot/Cstartup_app.S @@ -0,0 +1,194 @@ +/* Cstartup header for the application to be started by at91dfu + * (C) 2006 by Harald Welte <hwelte@hmw-consulting.de> + * + * 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 + * + */ + + +//#define DEBUG_LL + + .equ AIC_FVR, (260) + .equ AIC_EOICR, (304) + .equ AT91C_BASE_AIC, (0xFFFFF000) + .equ ARM_MODE_FIQ, 0x11 + .equ ARM_MODE_IRQ, 0x12 + .equ ARM_MODE_SVC, 0x13 + + .equ I_BIT, 0x80 + .equ F_BIT, 0x40 + + +#define AT91C_BASE_PIOA 0xFFFFF400 +#define AT91C_BASE_TC0 0xFFFA0000 +#define AT91C_TC_SWTRG (1 << 2) +#define PIOA_SODR 0x30 +#define PIOA_CODR 0x34 +#define PIOA_PDSR 0x3c +#define PIOA_ISR 0x4c +#define PIOA_IDR 0x44 +#define PIO_DATA (1 << 27) +#define TC_CCR 0x00 + + +#define PIO_LED1 (1 << 25) /* this only works on OpenPICC, not Olimex */ + +#ifdef DEBUG_LL +/* Debugging macros for switching on/off LED1 (green) */ +#define PIOA_PER 0xFFFFF400 +#define PIOA_OER 0xFFFFF410 + .macro led1on + ldr r2, =AT91C_BASE_PIOA + mov r1, #PIO_LED1 + str r1, [r2, #PIOA_CODR] + .endm + .macro led1off + ldr r2, =AT91C_BASE_PIOA + mov r1, #PIO_LED1 + str r1, [r2, #PIOA_SODR] + .endm + .macro ledinit + ldr r2, =PIOA_PER + mov r1, #PIO_LED1 + str r1, [r2] + ldr r2, =PIOA_OER + str r1, [r2] + led1off + .endm +#else + .macro ledinit + .endm + .macro led1on + .endm + .macro led1off + .endm +#endif + + .global _startup + .func _startup +_startup: + /* Relocate .data section (copy from Flash to RAM) */ + ldr r1, =_etext + ldr r2, =_data + ldr r3, =_edata +loop_r: cmp r2, r3 + ldrlo r0, [r1], #4 + strlo r0, [r2], #4 + blo loop_r + + /* Clear .bss section (Zero init) */ + mov r0, #0 + ldr r1, =__bss_start__ + ldr r2, =__bss_end__ +loop_z: cmp r1, r2 + strlo r0, [r1], #4 + blo loop_z + + /* initialize FIQ mode registers */ + msr CPSR_c, #ARM_MODE_FIQ | I_BIT | F_BIT + ldr r10, =AT91C_BASE_PIOA + ldr r12, =AT91C_BASE_TC0 + mov r9, #AT91C_TC_SWTRG + msr CPSR_c, #ARM_MODE_SVC + + led1on + + /* prepare C function call to main */ + mov r0, #0 /* argc = 0 */ + ldr lr, =exit + ldr r10, =main + + bx r10 + + .size _startup, . - _startup + .endfunc + +/* "exit" dummy to avoid sbrk write read etc. needed by the newlib default "exit" */ + .global exit + .func exit +exit: + b . + .size exit, . - exit + .endfunc + + +#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 */ + /* 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 + |