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gerrit-public.fairphone.software / kernel / msm-4.9 / f4bdbfc41b3cad813745f64fb849c298770da517 / . / arch / powerpc / boot / crt0.S
blob: 5a4215c4b0146aa063fe87c5bb503a398232f6d3 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
Olaf Heringdecd3002005-08-08 13:24:38 +1000[diff] [blame]12#include "ppc_asm.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]13
14 .text
Paul Mackerras66a45dd2006-01-14 15:04:06 +1100[diff] [blame]15 /* a procedure descriptor used when booting this as a COFF file */
16_zimage_start_opd:
17 .long _zimage_start, 0, 0, 0
18
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]19 .weak _zimage_start
Olaf Hering67a1b682005-10-28 17:46:49 -0700[diff] [blame]20 .globl _zimage_start
21_zimage_start:
Milton Miller160cc3e2007-03-21 09:02:53 -0600[diff] [blame]22 .globl _zimage_start_lib
23_zimage_start_lib:
Paul Mackerras66a45dd2006-01-14 15:04:06 +1100[diff] [blame]24 /* Work out the offset between the address we were linked at
25 and the address where we're running. */
Olaf Hering68643cf2005-11-17 22:09:02 +0100[diff] [blame]26 bl 1f
Paul Mackerras66a45dd2006-01-14 15:04:06 +1100[diff] [blame]271: mflr r0
Olaf Hering68643cf2005-11-17 22:09:02 +0100[diff] [blame]28 lis r9,1b@ha
29 addi r9,r9,1b@l
Olaf Heringa4497232005-10-28 17:46:48 -0700[diff] [blame]30 subf. r0,r9,r0
Paul Mackerras66a45dd2006-01-14 15:04:06 +1100[diff] [blame]31 beq 3f /* if running at same address as linked */
Olaf Heringa4497232005-10-28 17:46:48 -0700[diff] [blame]32
Paul Mackerras66a45dd2006-01-14 15:04:06 +1100[diff] [blame]33 /* The .got2 section contains a list of addresses, so add
34 the address offset onto each entry. */
Olaf Heringa4497232005-10-28 17:46:48 -0700[diff] [blame]35 lis r9,__got2_start@ha
36 addi r9,r9,__got2_start@l
37 lis r8,__got2_end@ha
38 addi r8,r8,__got2_end@l
39 subf. r8,r9,r8
Olaf Hering68643cf2005-11-17 22:09:02 +0100[diff] [blame]40 beq 3f
Olaf Heringa4497232005-10-28 17:46:48 -0700[diff] [blame]41 srwi. r8,r8,2
42 mtctr r8
43 add r9,r0,r9
Paul Mackerras66a45dd2006-01-14 15:04:06 +1100[diff] [blame]442: lwz r8,0(r9)
Olaf Heringa4497232005-10-28 17:46:48 -0700[diff] [blame]45 add r8,r8,r0
46 stw r8,0(r9)
47 addi r9,r9,4
Olaf Hering68643cf2005-11-17 22:09:02 +0100[diff] [blame]48 bdnz 2b
Olaf Heringa4497232005-10-28 17:46:48 -0700[diff] [blame]49
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]50 /* Do a cache flush for our text, in case the loader didn't */
Olaf Heringeacb1962006-03-04 13:15:40 +0100[diff] [blame]513: lis r9,_start@ha
52 addi r9,r9,_start@l
Olaf Heringa4497232005-10-28 17:46:48 -0700[diff] [blame]53 add r9,r0,r9
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]54 lis r8,_etext@ha
55 addi r8,r8,_etext@l
Olaf Heringa4497232005-10-28 17:46:48 -0700[diff] [blame]56 add r8,r0,r8
Olaf Hering68643cf2005-11-17 22:09:02 +0100[diff] [blame]574: dcbf r0,r9
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]58 icbi r0,r9
59 addi r9,r9,0x20
Olaf Heringeacb1962006-03-04 13:15:40 +0100[diff] [blame]60 cmplw cr0,r9,r8
Olaf Hering68643cf2005-11-17 22:09:02 +0100[diff] [blame]61 blt 4b
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]62 sync
63 isync
64
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]65 /* Clear the BSS */
66 lis r9,__bss_start@ha
67 addi r9,r9,__bss_start@l
Milton Millerf4bdbfc2007-03-28 02:21:02 -0600[diff] [blame^]68 add r9,r0,r9
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]69 lis r8,_end@ha
70 addi r8,r8,_end@l
Milton Millerf4bdbfc2007-03-28 02:21:02 -0600[diff] [blame^]71 add r8,r0,r8
72 li r10,0
735: stw r10,0(r9)
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]74 addi r9,r9,4
75 cmplw cr0,r9,r8
76 blt 5b
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]77
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]78 /* Possibly set up a custom stack */
79.weak _platform_stack_top
80 lis r8,_platform_stack_top@ha
81 addi r8,r8,_platform_stack_top@l
82 cmpwi r8,0
83 beq 6f
Milton Millerf4bdbfc2007-03-28 02:21:02 -0600[diff] [blame^]84 add r8,r0,r8
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]85 lwz r1,0(r8)
Milton Millerf4bdbfc2007-03-28 02:21:02 -0600[diff] [blame^]86 add r1,r0,r1
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]87 li r0,0
88 stwu r0,-16(r1) /* establish a stack frame */
896:
90
91 /* Call platform_init() */
92 bl platform_init
93
94 /* Call start */
David Gibsoncd197ff2007-03-05 14:24:52 +1100[diff] [blame]95 b start