#include "ppc_asm.h"
.text
+ /* a procedure descriptor used when booting this as a COFF file */
+ .globl _zimage_start_opd
+_zimage_start_opd:
+ .long _zimage_start, 0, 0, 0
+
+ .weak _zimage_start
.globl _zimage_start
_zimage_start:
- bl reloc_offset
-
-reloc_offset:
- mflr r0
- lis r9,reloc_offset@ha
- addi r9,r9,reloc_offset@l
+ .globl _zimage_start_lib
+_zimage_start_lib:
+ /* Work out the offset between the address we were linked at
+ and the address where we're running. */
+ bl 1f
+1: mflr r0
+ lis r9,1b@ha
+ addi r9,r9,1b@l
subf. r0,r9,r0
- beq clear_caches
+ beq 3f /* if running at same address as linked */
-reloc_got2:
+ /* The .got2 section contains a list of addresses, so add
+ the address offset onto each entry. */
lis r9,__got2_start@ha
addi r9,r9,__got2_start@l
lis r8,__got2_end@ha
addi r8,r8,__got2_end@l
subf. r8,r9,r8
- beq clear_caches
+ beq 3f
srwi. r8,r8,2
mtctr r8
add r9,r0,r9
-reloc_got2_loop:
- lwz r8,0(r9)
+2: lwz r8,0(r9)
add r8,r8,r0
stw r8,0(r9)
addi r9,r9,4
- bdnz reloc_got2_loop
+ bdnz 2b
-clear_caches:
- lis r9,_start@h
+ /* Do a cache flush for our text, in case the loader didn't */
+3: lis r9,_start@ha
+ addi r9,r9,_start@l
add r9,r0,r9
lis r8,_etext@ha
addi r8,r8,_etext@l
add r8,r0,r8
-1: dcbf r0,r9
+4: dcbf r0,r9
icbi r0,r9
addi r9,r9,0x20
- cmplwi 0,r9,8
- blt 1b
+ cmplw cr0,r9,r8
+ blt 4b
sync
isync
- mr r6,r1
- b start
+ /* Clear the BSS */
+ lis r9,__bss_start@ha
+ addi r9,r9,__bss_start@l
+ add r9,r0,r9
+ lis r8,_end@ha
+ addi r8,r8,_end@l
+ add r8,r0,r8
+ li r10,0
+5: stw r10,0(r9)
+ addi r9,r9,4
+ cmplw cr0,r9,r8
+ blt 5b
+
+ /* Possibly set up a custom stack */
+.weak _platform_stack_top
+ lis r8,_platform_stack_top@ha
+ addi r8,r8,_platform_stack_top@l
+ cmpwi r8,0
+ beq 6f
+ add r8,r0,r8
+ lwz r1,0(r8)
+ add r1,r0,r1
+ li r0,0
+ stwu r0,-16(r1) /* establish a stack frame */
+6:
+ /* Call platform_init() */
+ bl platform_init
+
+ /* Call start */
+ b start