diff options
Diffstat (limited to 'firmware/crt0.S')
| -rw-r--r-- | firmware/crt0.S | 77 |
1 files changed, 52 insertions, 25 deletions
diff --git a/firmware/crt0.S b/firmware/crt0.S index 5a5d0037ef..82f1b82a73 100644 --- a/firmware/crt0.S +++ b/firmware/crt0.S @@ -34,18 +34,62 @@ start: * Copyright (c) 2005, Bernard Leach <leachbj@bouncycastle.org> * */ - .equ PP5002_PROC_ID, 0xc4000000 - .equ PP5002COP_CTRL, 0xcf004058 - .equ PP5020_PROC_ID, 0x60000000 + .equ PP5002_PROC_ID, 0xc4000000 + .equ PP5002_COP_CTRL, 0xcf004058 + .equ PP5020_PROC_ID, 0x60000000 .equ PP5020_COP_CTRL, 0x60007004 start: +#ifndef BOOTLOADER +/* Zero out IBSS */ + ldr r2, =_iedata + ldr r3, =_iend + mov r4, #0 +1: + cmp r3, r2 + strhi r4, [r2], #4 + bhi 1b + +/* Copy the IRAM */ + ldr r2, =_iramcopy + ldr r3, =_iramstart + ldr r4, =_iramend +1: + cmp r4, r3 + ldrhi r5, [r2], #4 + strhi r5, [r3], #4 + bhi 1b +#endif + + /* Initialise bss section to zero */ + ldr r2, =_edata + ldr r3, =_end + mov r4, #0 +1: + cmp r3, r2 + strhi r4, [r2], #4 + bhi 1b + + /* Set up some stack and munge it with 0xdeadbeef */ + ldr sp, =stackend + mov r3, sp + ldr r2, =stackbegin + ldr r4, =0xdeadbeef +1: + cmp r3, r2 + strhi r4, [r2], #4 + bhi 1b + +#ifdef BOOTLOADER + /* TODO: the high part of the address is probably dependent on CONFIG_CPU. + Since we tend to use ifdefs for each chipset target + anyway, we might as well just hardcode it here. + */ + /* get the high part of our execute address */ ldr r0, =0xff000000 and r8, pc, r0 @ r8 is used later -#ifdef BOOTLOADER - #if CONFIG_CPU==PP5002 mov r0, #PP5002_PROC_ID #else @@ -75,15 +119,6 @@ cop_wake_start: ldr pc, [r0] 1: - /* setup some stack and munge it with 0xdeadbeef */ - ldr sp, =_stackend - mov r3, sp - ldr r2, =_stackbegin - ldr r4, =0xdeadbeef -.mungeloop: - str r4, [r2], #4 - cmp r2, r3 - bne .mungeloop /* get the high part of our execute address */ ldr r2, =0xffffff00 @@ -103,15 +138,6 @@ cop_wake_start: ldr pc, =start_loc /* jump to the relocated start_loc: */ start_loc: - /* Initialise bss section to zero */ - ldr r3, =_bssstart - ldr r1, =_bssend - mov r2, #0x0 - -1: - cmp r3, r1 - strcc r2, [r3], #4 - bcc 1b /* execute the loader - this will load an image to 0x10000000 */ bl main @@ -158,8 +184,9 @@ boot_table: /* here comes the boot table, don't move its offset */ .space 400 #else - /* TODO: Implement startup code */ - + /* Non-bootloader startup code */ + ldr r0, =main + mov pc, r0 #endif /* BOOTLOADER (iPod) */ #elif CONFIG_CPU == TCC730 |