xref: /openbmc/linux/arch/sh/boot/compressed/head_32.S (revision 842ed298)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 *  linux/arch/sh/boot/compressed/head.S
4 *
5 *  Copyright (C) 1999 Stuart Menefy
6 *  Copyright (C) 2003 SUGIOKA Toshinobu
7 */
8
9.text
10
11#include <asm/page.h>
12
13	.global	startup
14startup:
15	/* Load initial status register */
16	mov.l   init_sr, r1
17	ldc     r1, sr
18
19	/* Move myself to proper location if necessary */
20	mova	1f, r0
21	mov.l	1f, r2
22	cmp/eq	r2, r0
23	bt	clear_bss
24	sub	r0, r2
25	mov.l	bss_start_addr, r0
26	mov	#0xffffffe0, r1
27	and	r1, r0			! align cache line
28	mov.l	text_start_addr, r3
29	mov	r0, r1
30	sub	r2, r1
313:
32	mov.l	@r1, r4
33	mov.l	@(4,r1), r5
34	mov.l	@(8,r1), r6
35	mov.l	@(12,r1), r7
36	mov.l	@(16,r1), r8
37	mov.l	@(20,r1), r9
38	mov.l	@(24,r1), r10
39	mov.l	@(28,r1), r11
40	mov.l	r4, @r0
41	mov.l	r5, @(4,r0)
42	mov.l	r6, @(8,r0)
43	mov.l	r7, @(12,r0)
44	mov.l	r8, @(16,r0)
45	mov.l	r9, @(20,r0)
46	mov.l	r10, @(24,r0)
47	mov.l	r11, @(28,r0)
48#ifdef CONFIG_CPU_SH4
49	ocbwb	@r0
50#endif
51	cmp/hi	r3, r0
52	add	#-32, r0
53	bt/s	3b
54	 add	#-32, r1
55	mov.l	2f, r0
56	jmp	@r0
57	 nop
58
59	.align 2
601:	.long	1b
612:	.long	clear_bss
62text_start_addr:
63	.long	startup
64
65	/* Clear BSS */
66clear_bss:
67	mov.l	end_addr, r1
68	mov.l	bss_start_addr, r2
69	mov	#0, r0
70l1:
71	mov.l	r0, @-r1
72	cmp/eq	r1,r2
73	bf	l1
74
75	/* Set the initial pointer. */
76	mov.l	init_stack_addr, r0
77	mov.l	@r0, r15
78
79	/* Decompress the kernel */
80	mov.l	decompress_kernel_addr, r0
81	jsr	@r0
82	nop
83
84	/* Jump to the start of the decompressed kernel */
85	mov.l	kernel_start_addr, r0
86	jmp	@r0
87	nop
88
89	.align	2
90bss_start_addr:
91	.long	__bss_start
92end_addr:
93	.long	_end
94init_sr:
95	.long	0x500000F0	/* Privileged mode, Bank=0, Block=1, IMASK=0xF */
96kexec_magic:
97	.long	0x400000F0	/* magic used by kexec to parse zImage format */
98init_stack_addr:
99	.long	stack_start
100decompress_kernel_addr:
101	.long	decompress_kernel
102kernel_start_addr:
103#ifdef CONFIG_32BIT
104	.long	___pa(_text+PAGE_SIZE)
105#else
106	.long	_text+PAGE_SIZE
107#endif
108
109	.align	9
110fake_headers_as_bzImage:
111	.word	0
112	.ascii	"HdrS"		! header signature
113	.word	0x0202		! header version number (>= 0x0105)
114				! or else old loadlin-1.5 will fail)
115	.word	0		! default_switch
116	.word	0		! SETUPSEG
117	.word	0x1000
118	.word	0		! pointing to kernel version string
119	.byte	0		! = 0, old one (LILO, Loadlin,
120				! 0xTV: T=0 for LILO
121				!       V = version
122	.byte	1		! Load flags bzImage=1
123	.word	0x8000		! size to move, when setup is not
124	.long	0x100000	! 0x100000 = default for big kernel
125	.long	0		! address of loaded ramdisk image
126	.long	0		# its size in bytes
127