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
| /*
| * Copyright (C) 2009 Thomas Chou <thomas@wytron.com.tw>
| *
| * Based on arch/nios2/kernel/head.S
| *
| * This file is subject to the terms and conditions of the GNU General Public
| * License. See the file "COPYING" in the main directory of this archive
| * for more details.
| *
| */
|
| /*
| * This code can be loaded anywhere, eg FLASH ROM as reset vector,
| * as long as output does not overlap it.
| */
|
| #include <linux/linkage.h>
| #include <asm/cache.h>
|
| .text
| .set noat
| ENTRY(_start)
| wrctl status, r0 /* disable interrupt */
| /* invalidate all instruction cache */
| movia r1, NIOS2_ICACHE_SIZE
| movui r2, NIOS2_ICACHE_LINE_SIZE
| 1: initi r1
| sub r1, r1, r2
| bgt r1, r0, 1b
| /* invalidate all data cache */
| movia r1, NIOS2_DCACHE_SIZE
| movui r2, NIOS2_DCACHE_LINE_SIZE
| 1: initd 0(r1)
| sub r1, r1, r2
| bgt r1, r0, 1b
|
| nextpc r1 /* Find out where we are */
| chkadr:
| movia r2, chkadr
| beq r1, r2, finish_move /* We are running in correct address,
| done */
| /* move code, r1: src, r2: dest, r3: last dest */
| addi r1, r1, (_start - chkadr) /* Source */
| movia r2, _start /* Destination */
| movia r3, __bss_start /* End of copy */
| 1: ldw r8, 0(r1) /* load a word from [r1] */
| stw r8, 0(r2) /* stort a word to dest [r2] */
| addi r1, r1, 4 /* inc the src addr */
| addi r2, r2, 4 /* inc the dest addr */
| blt r2, r3, 1b
| /* flush the data cache after moving */
| movia r1, NIOS2_DCACHE_SIZE
| movui r2, NIOS2_DCACHE_LINE_SIZE
| 1: flushd 0(r1)
| sub r1, r1, r2
| bgt r1, r0, 1b
| movia r1, finish_move
| jmp r1 /* jmp to linked address */
|
| finish_move:
| /* zero out the .bss segment (uninitialized common data) */
| movia r2, __bss_start /* presume nothing is between */
| movia r1, _end /* the .bss and _end. */
| 1: stb r0, 0(r2)
| addi r2, r2, 1
| bne r1, r2, 1b
| /*
| * set up the stack pointer, some where higher than _end.
| * The stack space must be greater than 32K for decompress.
| */
| movia sp, 0x10000
| add sp, sp, r1
| /* save args passed from u-boot, maybe */
| addi sp, sp, -16
| stw r4, 0(sp)
| stw r5, 4(sp)
| stw r6, 8(sp)
| stw r7, 12(sp)
| /* decompress the kernel */
| call decompress_kernel
| /* pass saved args to kernel */
| ldw r4, 0(sp)
| ldw r5, 4(sp)
| ldw r6, 8(sp)
| ldw r7, 12(sp)
|
| /* flush all data cache after decompressing */
| movia r1, NIOS2_DCACHE_SIZE
| movui r2, NIOS2_DCACHE_LINE_SIZE
| 1: flushd 0(r1)
| sub r1, r1, r2
| bgt r1, r0, 1b
| /* flush all instruction cache */
| movia r1, NIOS2_ICACHE_SIZE
| movui r2, NIOS2_ICACHE_LINE_SIZE
| 1: flushi r1
| sub r1, r1, r2
| bgt r1, r0, 1b
| flushp
| /* jump to start real kernel */
| movia r1, (CONFIG_NIOS2_MEM_BASE | CONFIG_NIOS2_KERNEL_REGION_BASE)
| jmp r1
|
| .balign 512
| fake_headers_as_bzImage:
| .short 0
| .ascii "HdrS"
| .short 0x0202
| .short 0
| .short 0
| .byte 0x00, 0x10
| .short 0
| .byte 0
| .byte 1
| .byte 0x00, 0x80
| .long 0
| .long 0
|
|
