tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * kexec trampoline
3 *
4 * Based on code taken from kexec-tools and kexec-lite.
5 *
6 * Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation
7 * Copyright (C) 2006, Mohan Kumar M, IBM Corporation
8 * Copyright (C) 2013, Anton Blanchard, IBM Corporation
9 *
10 * This program is free software; you can redistribute it and/or modify it under
11 * the terms of the GNU General Public License as published by the Free
12 * Software Foundation (version 2 of the License).
13 */
14
15#include <asm/asm-compat.h>
16
17 .machine ppc64
18 .balign 256
19 .globl purgatory_start
20purgatory_start:
21 b master
22
23 /* ABI: possible run_at_load flag at 0x5c */
24 .org purgatory_start + 0x5c
25 .globl run_at_load
26run_at_load:
27 .long 0
28 .size run_at_load, . - run_at_load
29
30 /* ABI: slaves start at 60 with r3=phys */
31 .org purgatory_start + 0x60
32slave:
33 b .
34 /* ABI: end of copied region */
35 .org purgatory_start + 0x100
36 .size purgatory_start, . - purgatory_start
37
38/*
39 * The above 0x100 bytes at purgatory_start are replaced with the
40 * code from the kernel (or next stage) by setup_purgatory().
41 */
42
43master:
44 or %r1,%r1,%r1 /* low priority to let other threads catchup */
45 isync
46 mr %r17,%r3 /* save cpu id to r17 */
47 mr %r15,%r4 /* save physical address in reg15 */
48
49 or %r3,%r3,%r3 /* ok now to high priority, lets boot */
50 lis %r6,0x1
51 mtctr %r6 /* delay a bit for slaves to catch up */
52 bdnz . /* before we overwrite 0-100 again */
53
54 bl 0f /* Work out where we're running */
550: mflr %r18
56
57 /* load device-tree address */
58 ld %r3, (dt_offset - 0b)(%r18)
59 mr %r16,%r3 /* save dt address in reg16 */
60 li %r4,20
61 LWZX_BE %r6,%r3,%r4 /* fetch __be32 version number at byte 20 */
62 cmpwi %cr0,%r6,2 /* v2 or later? */
63 blt 1f
64 li %r4,28
65 STWX_BE %r17,%r3,%r4 /* Store my cpu as __be32 at byte 28 */
661:
67 /* load the kernel address */
68 ld %r4,(kernel - 0b)(%r18)
69
70 /* load the run_at_load flag */
71 /* possibly patched by kexec */
72 ld %r6,(run_at_load - 0b)(%r18)
73 /* and patch it into the kernel */
74 stw %r6,(0x5c)(%r4)
75
76 mr %r3,%r16 /* restore dt address */
77
78 li %r5,0 /* r5 will be 0 for kernel */
79
80 mfmsr %r11
81 andi. %r10,%r11,1 /* test MSR_LE */
82 bne .Little_endian
83
84 mtctr %r4 /* prepare branch to */
85 bctr /* start kernel */
86
87.Little_endian:
88 mtsrr0 %r4 /* prepare branch to */
89
90 clrrdi %r11,%r11,1 /* clear MSR_LE */
91 mtsrr1 %r11
92
93 rfid /* update MSR and start kernel */
94
95
96 .balign 8
97 .globl kernel
98kernel:
99 .8byte 0x0
100 .size kernel, . - kernel
101
102 .balign 8
103 .globl dt_offset
104dt_offset:
105 .8byte 0x0
106 .size dt_offset, . - dt_offset
107
108
109 .data
110 .balign 8
111.globl purgatory_sha256_digest
112purgatory_sha256_digest:
113 .skip 32
114 .size purgatory_sha256_digest, . - purgatory_sha256_digest
115
116 .balign 8
117.globl purgatory_sha_regions
118purgatory_sha_regions:
119 .skip 8 * 2 * 16
120 .size purgatory_sha_regions, . - purgatory_sha_regions