xref: /linux/arch/arm/kernel/relocate_kernel.S (revision b7f8f259896f669f131713b0c74ba4d008daa71d)
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