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
191
192
193
194
195
196
197
198
|
/* $OpenBSD: crt0.S,v 1.1 2008/04/02 21:53:18 miod Exp $ */
/*
* Copyright (c) 2008 Miodrag Vallat.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#define _KERNEL
#define _LOCORE
#include <machine/asm.h>
text
#ifdef STAGE1
ASLOCAL(image)
/*
* Binaries loaded *from disk* by the BUG start with two special words.
*
* The first word contains the initial stack address, and the second
* word contains the initial instruction pointer.
*
* If the initial instruction pointer is below the address the file was
* loaded at (which is found in the VID block or in the NIOT settings),
* it is interpreted as an offset within the loaded image.
*/
.long _ASM_LABEL(image) - 0x10
.long _ASM_LABEL(start) - _ASM_LABEL(image)
#endif /* STAGE1 */
#ifdef STAGE2
/*
* bootxx runs the second-stage binary at its entry + 8, in case
* it contains the special two words.
*/
NOP
NOP
#endif
ASGLOBAL(start)
/*
* Registers on entry:
* r2 boot device lun
* r3 boot controller lun
* r4 cold/warm boot mode (`IPL\01')
* r5 boot controller address
* r6 entry point of loaded program (i.e. address of start)
* r7 disk boot: address of media configuration block, zero if none
* net boot: boot information packet address
* r8 start of command line (loaded file if netboot)
* r9 end of command line
* r10 net boot: start of optional argument
* r11 net boot: end of optional argument
* r12 net boot: bit 0 set if autoboot
* r31 stack, as setup above
*/
#if defined(STAGE2) || defined(NETBOOT)
/*
* We first relocate ourselves to our preferred address.
* This helps netbooting if the NIOT address (defaulting to
* 001f0000) does not match ours, or if we are loaded by an
* old stage1 at the wrong address.
*/
or.u r20, r0, hi16(_ASM_LABEL(start))
or r20, r20, lo16(_ASM_LABEL(start))
cmp r21, r6, r20
bb1 eq, r21, reloc_done
or.u r22, r0, hi16(_C_LABEL(end))
or r22, r22, lo16(_C_LABEL(end))
bb1.n lt, r21, reloc_down
or r25, r0, r6
/*
* Relocate from r25 to r20, moving up
*/
reloc_up:
ld r24, r25, r0
st r24, r20, r0
add r20, r20, 4
cmp r21, r20, r22
bb1.n ne, r21, reloc_up
add r25, r25, 4
br reloc_done
/*
* Relocate from r25 to r20, moving down
*/
reloc_down:
subu r26, r22, r20 /* _end - start */
addu r25, r25, r26
1:
subu r25, r25, 4
ld r24, r25, r0
subu r22, r22, 4
st r24, r22, r0
cmp r21, r20, r22
bb1 ne, r21, 1b
reloc_done:
or.u r20, r0, hi16(_ASM_LABEL(start_relocated))
or r20, r20, lo16(_ASM_LABEL(start_relocated))
jmp.n r20
or r6, r20, r0 /* for stack initialization below */
ASLOCAL(start_relocated)
#endif /* STAGE2 || NETBOOT */
/*
* Clear BSS.
*/
or.u r20, r0, hi16(_C_LABEL(edata))
or r20, r20, lo16(_C_LABEL(edata))
or.u r22, r0, hi16(_C_LABEL(end))
or r22, r22, lo16(_C_LABEL(end))
1: st r0, r20, r0
add r20, r20, 4
cmp r21, r20, r22
bb1 ne, r21, 1b
/*
* Setup our stack - it might not have been set up correctly.
* We'll use the memory below text as stack, aligned to 0x10
* bytes.
*/
clr r31, r6, 4<0>
/*
* Save our arguments so that all registers are available to
* C code.
*/
or.u r20, r0, hi16(_C_LABEL(bugargs))
or r20, r20, lo16(_C_LABEL(bugargs))
st r2, r20, 0x00 /* dev_lun */
st r3, r20, 0x04 /* ctrl_lun */
st r4, r20, 0x08 /* flags */
st r5, r20, 0x0c /* ctrl_addr */
st r6, r20, 0x10 /* entry */
st r7, r20, 0x14 /* conf_blk */
#ifdef NETBOOT
st r10, r20, 0x18 /* arg_start */
st r11, r20, 0x1c /* arg_end */
#else
st r8, r20, 0x18 /* arg_start */
st r9, r20, 0x1c /* arg_end */
#endif /* NETBOOT */
/*
* NUL-terminate arg_end, if it is not.
*/
#ifdef NETBOOT
st.b r0, r11, r0
#else
st.b r0, r9, r0
#endif
/*
* PSR when booted from the BUG has SFU1..SFU7 disabled.
* Enable SFU1 (the FPU) for the C code to be able to use it
* if necessary.
*/
ldcr r20, PSR
clr r20, r20, 1<PSR_FPU_DISABLE_BIT>
stcr r20, PSR
NOP
bsr _C_LABEL(main)
bsr _C_LABEL(_rtt)
1: br 1b
data
GLOBAL(bugargs)
.space 4 /* dev_lun */
.space 4 /* ctrl_lun */
.space 4 /* flags */
.space 4 /* ctrl_addr */
.space 4 /* entry */
.space 4 /* conf_blk */
.space 4 /* arg_start */
.space 4 /* arg_end */
|
