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
|
/******************************************************************************
* Copyright (c) 2004, 2008 IBM Corporation
* All rights reserved.
* This program and the accompanying materials
* are made available under the terms of the BSD License
* which accompanies this distribution, and is available at
* http://www.opensource.org/licenses/bsd-license.php
*
* Contributors:
* IBM Corporation - initial implementation
*****************************************************************************/
#include <rtas.h>
/*
Function:
Input:
r3: Destination to copy rtas code to
r4: Configuration
Output:
r3: Entry point for rtas calls
Decription: Called by OpenFirmware to instantiate rtas, needs to copy
itself to destination, also do a relocations.
*/
.extern rtas_entry
.extern .stack
.extern _got
.extern _got_end
.extern __bss_start
.extern __bss_end
.extern rtas_config
.section ".rtasstart","ax";
.align 3
.globl _rtas_start
_rtas_start:
mflr r10 # save link register
bcl 20,31,.over # branch (always) to .over
.base:
.align 3
/* Our Open Firmware needs to know the size of the RTAS binary and the
* size & address of the RTAS function jump table. SLOF always looks for this
* information in the following three quads here at the very beginning of the
* RTAS binary at offset 8. So DO NOT DELETE/MOVE them! */
._rtas_size: .quad _rtas_end-_rtas_start
._ptr_to_func_tab: .quad rtas_func_tab-_rtas_start
._ptr_to_func_tab_size: .quad rtas_func_tab_size-_rtas_start
/* The other variables are not accessed by SLOF anymore: */
._rel_offset: .quad _reloc_table_start-_rtas_start
._rel_end_offset: .quad _reloc_table_end-_rtas_start
._bss_offset: .quad __bss_start-_rtas_start
._bss_end_offset: .quad __bss_end-_rtas_start
._rtas_entry_offset: .quad rtas_entry-_rtas_start
._rtas_config_offset: .quad rtas_config-_rtas_start
._rtas_stack: .quad .stack-_rtas_start+RTAS_STACKSIZE-0x60
._rtas_toc: .quad _got-_rtas_start+0x8000
.over:
mflr r8 # gpr 8 is the base
addi r8,r8,_rtas_start-.base # points to _rtas_start
mr r11,r4 # Save config value
# Copy rtas code
ld r5,._rtas_size-_rtas_start(r8)
mr r4,r8 # Start of rtas
addi r6,r3,-8 # Destination
addi r4,r4,-8 # Source
srdi r5,r5,3 # Count in quads
mtctr r5
0:
ldu r0,8(r4)
stdu r0,8(r6)
bdnz 0b
# Clear bss
ld r4,._bss_offset-_rtas_start(r8)
ld r5,._bss_end_offset-_rtas_start(r8)
li r0,0
add r6,r3,r4 # Address bss in copied code
addi r6,r6,-8
sub r5,r5,r4 # Calculate bss size
srdi r5,r5,3 # Count in quads
mtctr r5
0:
stdu r0,8(r6)
bdnz 0b
# Relocate got
ld r4, ._rel_offset-_rtas_start(r8)
ld r5, ._rel_end_offset-_rtas_start(r8)
sub r5, r5,r4 # Calculate reloc table size
cmpdi r5, 0 # No reloc table ?
beq 1f
add r4, r4, r3 # Calculate reloc table address
addi r4, r4, -4
srdi r5, r5, 2 # Count in words
mtctr r5
0:
lwzu r6, 4(r4) # Load offset out of reloc table
ldx r0, r6, r3 # Load value
add r0, r0, r3 # Add relocation offset = load address
stdx r0, r6, r3
bdnz 0b
1:
# Save config data
ld r5,._rtas_config_offset-_rtas_start(r8)
add r5,r5,r3
std r11,0(r5)
# Flush to memory
mr r4,r3 # Destination address
ld r5,._rtas_size-_rtas_start(r8)
add r5,r5,r4
addi r5,r5,127
rlwinm r4,r4,0,0,24
rlwinm r5,r5,0,0,24
sub r5,r5,r4
srwi r5,r5,7
mtctr r5
0:
dcbst 0,r4
sync
icbi 0,r4
sync
isync
addi r4,r4,128
bdnz 0b
# Call init function
mfmsr r11 # Switch to 64 bit mode
mr r7,r11
rotldi r11,r11,1
ori r11,r11,1
rotldi r11,r11,63
mtmsrd r11
isync
mr r9,r1 # save old stack pointer
ld r1,._rtas_stack-_rtas_start(r8) # load new stack pointer
add r1,r1,r3
std r9,0(r1) # save stack pointer
std r2,64(r1) # save toc
std r7,72(r1) # save old msr value
ld r2,._rtas_toc-_rtas_start(r8) # load got pointer
add r2,r2,r3
bl save_regs_r3_r12
bl .rtas_init
bl restore_regs_r3_r12
ld r11,72(r1) # restore msr value
ld r2,64(r1) # restore toc
ld r1,0(r1) # get old stack
mtmsrd r11 # restore msr
isync
# Return rtas entry
ld r4,._rtas_entry_offset-_rtas_start(r8)
add r3,r3,r4
mtlr r10
blr
|
