xref: /openbmc/linux/arch/sh/boot/compressed/head_32.S (revision b6dcefde)
1/*
2 *  linux/arch/sh/boot/compressed/head.S
3 *
4 *  Copyright (C) 1999 Stuart Menefy
5 *  Copyright (C) 2003 SUGIOKA Toshinobu
6 */
7
8.text
9
10#include <asm/page.h>
11
12	.global	startup
13startup:
14	/* Load initial status register */
15	mov.l   init_sr, r1
16	ldc     r1, sr
17
18	/* Move myself to proper location if necessary */
19	mova	1f, r0
20	mov.l	1f, r2
21	cmp/eq	r2, r0
22	bt	clear_bss
23	sub	r0, r2
24	mov.l	bss_start_addr, r0
25	mov	#0xffffffe0, r1
26	and	r1, r0			! align cache line
27	mov.l	text_start_addr, r3
28	mov	r0, r1
29	sub	r2, r1
303:
31	mov.l	@r1, r4
32	mov.l	@(4,r1), r5
33	mov.l	@(8,r1), r6
34	mov.l	@(12,r1), r7
35	mov.l	@(16,r1), r8
36	mov.l	@(20,r1), r9
37	mov.l	@(24,r1), r10
38	mov.l	@(28,r1), r11
39	mov.l	r4, @r0
40	mov.l	r5, @(4,r0)
41	mov.l	r6, @(8,r0)
42	mov.l	r7, @(12,r0)
43	mov.l	r8, @(16,r0)
44	mov.l	r9, @(20,r0)
45	mov.l	r10, @(24,r0)
46	mov.l	r11, @(28,r0)
47#ifdef CONFIG_CPU_SH4
48	ocbwb	@r0
49#endif
50	cmp/hi	r3, r0
51	add	#-32, r0
52	bt/s	3b
53	 add	#-32, r1
54	mov.l	2f, r0
55	jmp	@r0
56	 nop
57
58	.align 2
591:	.long	1b
602:	.long	clear_bss
61text_start_addr:
62	.long	startup
63
64	/* Clear BSS */
65clear_bss:
66	mov.l	end_addr, r1
67	mov.l	bss_start_addr, r2
68	mov	#0, r0
69l1:
70	mov.l	r0, @-r1
71	cmp/eq	r1,r2
72	bf	l1
73
74	/* Set the initial pointer. */
75	mov.l	init_stack_addr, r0
76	mov.l	@r0, r15
77
78	/* Decompress the kernel */
79	mov.l	decompress_kernel_addr, r0
80	jsr	@r0
81	nop
82
83	/* Jump to the start of the decompressed kernel */
84	mov.l	kernel_start_addr, r0
85	jmp	@r0
86	nop
87
88	.align	2
89bss_start_addr:
90	.long	__bss_start
91end_addr:
92	.long	_end
93init_sr:
94	.long	0x400000F0	/* Privileged mode, Bank=0, Block=0, IMASK=0xF */
95init_stack_addr:
96	.long	stack_start
97decompress_kernel_addr:
98	.long	decompress_kernel
99kernel_start_addr:
100	.long	_text+PAGE_SIZE
101
102	.align	9
103fake_headers_as_bzImage:
104	.word	0
105	.ascii	"HdrS"		! header signature
106	.word	0x0202		! header version number (>= 0x0105)
107				! or else old loadlin-1.5 will fail)
108	.word	0		! default_switch
109	.word	0		! SETUPSEG
110	.word	0x1000
111	.word	0		! pointing to kernel version string
112	.byte	0		! = 0, old one (LILO, Loadlin,
113				! 0xTV: T=0 for LILO
114				!       V = version
115	.byte	1		! Load flags bzImage=1
116	.word	0x8000		! size to move, when setup is not
117	.long	0x100000	! 0x100000 = default for big kernel
118	.long	0		! address of loaded ramdisk image
119	.long	0		# its size in bytes
120