1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * relocate_kernel.S - put the kernel image in place to boot
4 */
5
6#include <linux/linkage.h>
7#include <asm/assembler.h>
8#include <asm/asm-offsets.h>
9#include <asm/kexec.h>
10
11 .align 3 /* not needed for this code, but keeps fncpy() happy */
12
13ENTRY(relocate_new_kernel)
14
15 adr r7, relocate_new_kernel_end
16 ldr r0, [r7, #KEXEC_INDIR_PAGE]
17 ldr r1, [r7, #KEXEC_START_ADDR]
18
19 /*
20 * If there is no indirection page (we are doing crashdumps)
21 * skip any relocation.
22 */
23 cmp r0, #0
24 beq 2f
25
260: /* top, read another word for the indirection page */
27 ldr r3, [r0],#4
28
29 /* Is it a destination page. Put destination address to r4 */
30 tst r3,#1
31 beq 1f
32 bic r4,r3,#1
33 b 0b
341:
35 /* Is it an indirection page */
36 tst r3,#2
37 beq 1f
38 bic r0,r3,#2
39 b 0b
401:
41
42 /* are we done ? */
43 tst r3,#4
44 beq 1f
45 b 2f
46
471:
48 /* is it source ? */
49 tst r3,#8
50 beq 0b
51 bic r3,r3,#8
52 mov r6,#1024
539:
54 ldr r5,[r3],#4
55 str r5,[r4],#4
56 subs r6,r6,#1
57 bne 9b
58 b 0b
59
602:
61 /* Jump to relocated kernel */
62 mov lr, r1
63 mov r0, #0
64 ldr r1, [r7, #KEXEC_MACH_TYPE]
65 ldr r2, [r7, #KEXEC_R2]
66 ARM( ret lr )
67 THUMB( bx lr )
68
69ENDPROC(relocate_new_kernel)
70
71 .align 3
72relocate_new_kernel_end:
73
74 .globl relocate_new_kernel_size
75relocate_new_kernel_size:
76 .long relocate_new_kernel_end - relocate_new_kernel
77
78
79

source code of linux/arch/arm/kernel/relocate_kernel.S