summaryrefslogtreecommitdiffstats
path: root/board/nokia/rx51/lowlevel_init.S
blob: 420ad13a12cb09252fe08cb460987698840ecfe8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
/*
 * (C) Copyright 2011-2012
 * Pali Rohár <pali.rohar@gmail.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <config.h>

relocaddr:		/* address of this relocaddr section after coping */
	.word .		/* address of section (calculated at compile time) */

startaddr:		/* address of u-boot after copying */
	.word CONFIG_SYS_TEXT_BASE

kernaddr:		/* address of kernel after copying */
	.word KERNEL_ADDRESS

kernsize:		/* maximal size of kernel image */
	.word KERNEL_MAXSIZE

kernoffs:		/* offset of kernel image in loaded u-boot */
	.word KERNEL_OFFSET

imagesize:		/* maximal size of image */
	.word IMAGE_MAXSIZE

ih_magic:		/* IH_MAGIC in big endian from include/image.h */
	.word 0x56190527

/*
 * Routine: save_boot_params (called after reset from start.S)
 * Description: Copy attached kernel to address KERNEL_ADDRESS
 *              Copy u-boot to address CONFIG_SYS_TEXT_BASE
 *              Return to copied u-boot address
 */

.global save_boot_params
save_boot_params:
	/* Get return address */
	ldr	lr, =save_boot_params_ret

/* Copy valid attached kernel to address KERNEL_ADDRESS */

copy_kernel_start:
	adr	r0, relocaddr	/* r0 - address of section relocaddr */
	ldr	r1, relocaddr	/* r1 - address of relocaddr after relocation */
	cmp	r0, r1

	/* r4 - calculated offset */
	subhi	r4, r0, r1
	sublo	r4, r1, r0

	/* r0 - start of kernel before */
	ldr	r0, startaddr
	addhi	r0, r0, r4
	sublo	r0, r0, r4
	ldr	r1, kernoffs
	add	r0, r0, r1

	/* r3 - start of kernel after */
	ldr	r3, kernaddr

	/* r2 - end of kernel after */
	ldr	r1, kernsize
	add	r2, r3, r1

	/* r1 - end of kernel before */
	add	r1, r0, r1

	/* remove header in target kernel */
	mov	r5, #0
	str	r5, [r3]

	/* check for valid kernel uImage */
	ldr	r4, [r0]	/* r4 - 4 bytes header of kernel */
	ldr	r5, ih_magic	/* r5 - IH_MAGIC */
	cmp	r4, r5
	bne	copy_kernel_end	/* skip if invalid image */

copy_kernel_loop:
	ldmdb	r1!, {r3 - r10}
	stmdb	r2!, {r3 - r10}
	cmp	r1, r0
	bhi	copy_kernel_loop

copy_kernel_end:
	mov	r5, #0
	str	r5, [r0]	/* remove 4 bytes header of kernel */


/* Fix u-boot code */

fix_start:
	adr	r0, relocaddr	/* r0 - address of section relocaddr */
	ldr	r1, relocaddr	/* r1 - address of relocaddr after relocation */
	cmp	r0, r1

	beq	copy_uboot_end	/* skip if u-boot is on correct address */

	/* r5 - calculated offset */
	subhi	r5, r0, r1
	sublo	r5, r1, r0

	/* r6 - maximal u-boot size */
	ldr	r6, imagesize

	/* r1 - start of u-boot after */
	ldr	r1, startaddr

	/* r0 - start of u-boot before */
	addhi	r0, r1, r5
	sublo	r0, r1, r5

	/* check if we need to move uboot copy code before calling it */
	cmp	r5, r6
	bhi	copy_uboot_start /* now coping u-boot code directly is safe */


copy_code_start:
	/* r0 - start of u-boot before */
	/* r1 - start of u-boot after */
	/* r6 - maximal u-boot size */

	/* r7 - maximal kernel size */
	ldr	r7, kernsize

	/* r4 - end of kernel before */
	add	r4, r0, r6
	add	r4, r4, r7

	/* r5 - end of u-boot after */
	ldr	r5, startaddr
	add	r5, r5, r6

	/* r2 - start of loop code after */
	cmp	r4, r5		/* higher address (r4 or r5) */
	movhs	r2, r4
	movlo	r2, r5

	/* r3 - end of loop code before */
	adr	r3, end

	/* r4 - end of loop code after */
	adr	r4, copy_uboot_start
	sub	r4, r3, r4
	add	r4, r2, r4

copy_code_loop:
	ldmdb	r3!, {r7 - r10}
	stmdb	r4!, {r7 - r10}
	cmp	r4, r2
	bhi	copy_code_loop

copy_code_end:
	mov	pc, r2


/* Copy u-boot to address CONFIG_SYS_TEXT_BASE */

copy_uboot_start:
	/* r0 - start of u-boot before */
	/* r1 - start of u-boot after */
	/* r6 - maximal u-boot size */

	/* r2 - end of u-boot after */
	add	r2, r1, r6

	/* condition for copying from left to right */
	cmp	r0, r1
	addlo	r1, r0, r6	/* r1 - end of u-boot before */
	blo	copy_uboot_loop_right

copy_uboot_loop_left:
	ldmia	r0!, {r3 - r10}
	stmia	r1!, {r3 - r10}
	cmp	r1, r2
	blo	copy_uboot_loop_left
	b	copy_uboot_end

copy_uboot_loop_right:
	ldmdb	r1!, {r3 - r10}
	stmdb	r2!, {r3 - r10}
	cmp	r1, r0
	bhi	copy_uboot_loop_right

copy_uboot_end:
	bx	lr

end: