projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * Copyright (C) Paul Mackerras 1997. | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or | |
| 5 | * modify it under the terms of the GNU General Public License | |
| 6 | * as published by the Free Software Foundation; either version | |
| 7 | * 2 of the License, or (at your option) any later version. | |
| 8 | * | |
| 9 | * NOTE: this code runs in 32 bit mode and is packaged as ELF32. | |
| 10 | */ | |
| 11 | ||
| decd300b | 12 | #include "ppc_asm.h" |
| 1da177e4 LT |
13 | |
| 14 | .text | |
| 66a45dd3 | 15 | /* a procedure descriptor used when booting this as a COFF file */ |
| f40e524e | 16 | .globl _zimage_start_opd |
| 66a45dd3 PM |
17 | _zimage_start_opd: |
| 18 | .long _zimage_start, 0, 0, 0 | |
| 19 | ||
| cd197ffc | 20 | .weak _zimage_start |
| 67a1b682 OH |
21 | .globl _zimage_start |
| 22 | _zimage_start: | |
| 160cc3ec MM |
23 | .globl _zimage_start_lib |
| 24 | _zimage_start_lib: | |
| 66a45dd3 PM |
25 | /* Work out the offset between the address we were linked at |
| 26 | and the address where we're running. */ | |
| 68643cfb | 27 | bl 1f |
| 66a45dd3 | 28 | 1: mflr r0 |
| 68643cfb OH |
29 | lis r9,1b@ha |
| 30 | addi r9,r9,1b@l | |
| a4497235 | 31 | subf. r0,r9,r0 |
| 66a45dd3 | 32 | beq 3f /* if running at same address as linked */ |
| a4497235 | 33 | |
| 66a45dd3 PM |
34 | /* The .got2 section contains a list of addresses, so add |
| 35 | the address offset onto each entry. */ | |
| a4497235 OH |
36 | lis r9,__got2_start@ha |
| 37 | addi r9,r9,__got2_start@l | |
| 38 | lis r8,__got2_end@ha | |
| 39 | addi r8,r8,__got2_end@l | |
| 40 | subf. r8,r9,r8 | |
| 68643cfb | 41 | beq 3f |
| a4497235 OH |
42 | srwi. r8,r8,2 |
| 43 | mtctr r8 | |
| 44 | add r9,r0,r9 | |
| 66a45dd3 | 45 | 2: lwz r8,0(r9) |
| a4497235 OH |
46 | add r8,r8,r0 |
| 47 | stw r8,0(r9) | |
| 48 | addi r9,r9,4 | |
| 68643cfb | 49 | bdnz 2b |
| a4497235 | 50 | |
| cd197ffc | 51 | /* Do a cache flush for our text, in case the loader didn't */ |
| eacb1962 OH |
52 | 3: lis r9,_start@ha |
| 53 | addi r9,r9,_start@l | |
| a4497235 | 54 | add r9,r0,r9 |
| 1da177e4 LT |
55 | lis r8,_etext@ha |
| 56 | addi r8,r8,_etext@l | |
| a4497235 | 57 | add r8,r0,r8 |
| 68643cfb | 58 | 4: dcbf r0,r9 |
| 1da177e4 LT |
59 | icbi r0,r9 |
| 60 | addi r9,r9,0x20 | |
| eacb1962 | 61 | cmplw cr0,r9,r8 |
| 68643cfb | 62 | blt 4b |
| 1da177e4 LT |
63 | sync |
| 64 | isync | |
| 65 | ||
| cd197ffc DG |
66 | /* Clear the BSS */ |
| 67 | lis r9,__bss_start@ha | |
| 68 | addi r9,r9,__bss_start@l | |
| f4bdbfc4 | 69 | add r9,r0,r9 |
| cd197ffc DG |
70 | lis r8,_end@ha |
| 71 | addi r8,r8,_end@l | |
| f4bdbfc4 MM |
72 | add r8,r0,r8 |
| 73 | li r10,0 | |
| 74 | 5: stw r10,0(r9) | |
| cd197ffc DG |
75 | addi r9,r9,4 |
| 76 | cmplw cr0,r9,r8 | |
| 77 | blt 5b | |
| 1da177e4 | 78 | |
| cd197ffc DG |
79 | /* Possibly set up a custom stack */ |
| 80 | .weak _platform_stack_top | |
| 81 | lis r8,_platform_stack_top@ha | |
| 82 | addi r8,r8,_platform_stack_top@l | |
| 83 | cmpwi r8,0 | |
| 84 | beq 6f | |
| f4bdbfc4 | 85 | add r8,r0,r8 |
| cd197ffc | 86 | lwz r1,0(r8) |
| f4bdbfc4 | 87 | add r1,r0,r1 |
| cd197ffc DG |
88 | li r0,0 |
| 89 | stwu r0,-16(r1) /* establish a stack frame */ | |
| 90 | 6: | |
| 91 | ||
| 92 | /* Call platform_init() */ | |
| 93 | bl platform_init | |
| 94 | ||
| 95 | /* Call start */ | |
| cd197ffc | 96 | b start |