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
|
/*
* Code that sets up the DRAM registers, calls the
* decompressor to unpack the piggybacked kernel, and jumps.
*
* Copyright (C) 1999 - 2006, Axis Communications AB
*/
#define ASSEMBLER_MACROS_ONLY
#include <hwregs/asm/reg_map_asm.h>
#include <mach/startup.inc>
#define RAM_INIT_MAGIC 0x56902387
#define COMMAND_LINE_MAGIC 0x87109563
;; Exported symbols
.globl input_data
.text
start:
di
;; Start clocks for used blocks.
START_CLOCKS
;; Initialize the DRAM registers.
cmp.d RAM_INIT_MAGIC, $r8 ; Already initialized?
beq dram_init_finished
nop
#if defined CONFIG_ETRAXFS
#include "../../arch-v32/mach-fs/dram_init.S"
#elif defined CONFIG_CRIS_MACH_ARTPEC3
#include "../../arch-v32/mach-a3/dram_init.S"
#else
#error Only ETRAXFS and ARTPEC-3 supported!
#endif
dram_init_finished:
GIO_INIT
;; Setup the stack to a suitably high address.
;; We assume 8 MB is the minimum DRAM and put
;; the SP at the top for now.
move.d 0x40800000, $sp
;; Figure out where the compressed piggyback image is.
;; It is either in [NOR] flash (we don't want to copy it
;; to DRAM before unpacking), or copied to DRAM
;; by the [NAND] flash boot loader.
;; The piggyback image is at _edata, but relative to where the
;; image is actually located in memory, not where it is linked
;; (the decompressor is linked at 0x40700000+ and runs there).
;; Use (_edata - herami) as offset to the current PC.
hereami:
lapcq ., $r5 ; get PC
and.d 0x7fffffff, $r5 ; strip any non-cache bit
move.d $r5, $r0 ; source address of 'herami'
add.d _edata, $r5
sub.d hereami, $r5 ; r5 = flash address of '_edata'
move.d hereami, $r1 ; destination
;; Copy text+data to DRAM
move.d _edata, $r2 ; end destination
1: move.w [$r0+], $r3 ; from herami+ source
move.w $r3, [$r1+] ; to hereami+ destination (linked address)
cmp.d $r2, $r1 ; finish when destination == _edata
bcs 1b
nop
move.d input_data, $r0 ; for the decompressor
move.d $r5, [$r0] ; for the decompressor
;; Clear the decompressors BSS (between _edata and _end)
moveq 0, $r0
move.d _edata, $r1
move.d _end, $r2
1: move.w $r0, [$r1+]
cmp.d $r2, $r1
bcs 1b
nop
;; Save command line magic and address.
move.d _cmd_line_magic, $r0
move.d $r10, [$r0]
move.d _cmd_line_addr, $r0
move.d $r11, [$r0]
;; Save boot source indicator
move.d _boot_source, $r0
move.d $r12, [$r0]
;; Do the decompression and save compressed size in _inptr
jsr decompress_kernel
nop
;; Restore boot source indicator
move.d _boot_source, $r12
move.d [$r12], $r12
;; Restore command line magic and address.
move.d _cmd_line_magic, $r10
move.d [$r10], $r10
move.d _cmd_line_addr, $r11
move.d [$r11], $r11
;; Put start address of root partition in r9 so the kernel can use it
;; when mounting from flash
move.d input_data, $r0
move.d [$r0], $r9 ; flash address of compressed kernel
move.d inptr, $r0
add.d [$r0], $r9 ; size of compressed kernel
cmp.d 0x40000000, $r9 ; image in DRAM ?
blo enter_kernel ; no, must be [NOR] flash, jump
nop ; delay slot
and.d 0x001fffff, $r9 ; assume compressed kernel was < 2M
enter_kernel:
;; Enter the decompressed kernel
move.d RAM_INIT_MAGIC, $r8 ; Tell kernel that DRAM is initialized
jump 0x40004000 ; kernel is linked to this address
nop
.data
input_data:
.dword 0 ; used by the decompressor
_cmd_line_magic:
.dword 0
_cmd_line_addr:
.dword 0
_boot_source:
.dword 0
#if defined CONFIG_ETRAXFS
#include "../../arch-v32/mach-fs/hw_settings.S"
#elif defined CONFIG_CRIS_MACH_ARTPEC3
#include "../../arch-v32/mach-a3/hw_settings.S"
#else
#error Only ETRAXFS and ARTPEC-3 supported!
#endif
|
