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
|
/*
Copyright Oliver Kowalke 2009.
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt)
*/
/******************************************************
* *
* ------------------------------------------------- *
* | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | *
* ------------------------------------------------- *
* | 0 | 4 | 8 | 12 | 16 | 20 | 24 | 28 | *
* ------------------------------------------------- *
* | F14 | F15 | F16 | F17 | *
* ------------------------------------------------- *
* ------------------------------------------------- *
* | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | *
* ------------------------------------------------- *
* | 32 | 36 | 40 | 44 | 48 | 52 | 56 | 60 | *
* ------------------------------------------------- *
* | F18 | F19 | F20 | F21 | *
* ------------------------------------------------- *
* ------------------------------------------------- *
* | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | *
* ------------------------------------------------- *
* | 64 | 68 | 72 | 76 | 80 | 84 | 88 | 92 | *
* ------------------------------------------------- *
* | F22 | F23 | F24 | F25 | *
* ------------------------------------------------- *
* ------------------------------------------------- *
* | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | *
* ------------------------------------------------- *
* | 96 | 100 | 104 | 108 | 112 | 116 | 120 | 124 | *
* ------------------------------------------------- *
* | F26 | F27 | F28 | F29 | *
* ------------------------------------------------- *
* ------------------------------------------------- *
* | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | *
* ------------------------------------------------- *
* | 128 | 132 | 136 | 140 | 144 | 148 | 152 | 156 | *
* ------------------------------------------------- *
* | F30 | F31 | fpscr | R13 | R14 | *
* ------------------------------------------------- *
* ------------------------------------------------- *
* | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | *
* ------------------------------------------------- *
* | 160 | 164 | 168 | 172 | 176 | 180 | 184 | 188 | *
* ------------------------------------------------- *
* | R15 | R16 | R17 | R18 | R19 | R20 | R21 | R22 | *
* ------------------------------------------------- *
* ------------------------------------------------- *
* | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | *
* ------------------------------------------------- *
* | 192 | 196 | 200 | 204 | 208 | 212 | 216 | 220 | *
* ------------------------------------------------- *
* | R23 | R24 | R25 | R26 | R27 | R28 | R29 | R30 | *
* ------------------------------------------------- *
* ------------------------------------------------- *
* | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | *
* ------------------------------------------------- *
* | 224 | 228 | 232 | 236 | 240 | 244 | 248 | 252 | *
* ------------------------------------------------- *
* | R31 |hiddn| CR | LR | PC |bchai|linkr| FCTX| *
* ------------------------------------------------- *
* ------------------------------------------------- *
* | 64 | | *
* ------------------------------------------------- *
* | 256 | | *
* ------------------------------------------------- *
* | DATA| | *
* ------------------------------------------------- *
* *
*******************************************************/
.text
.globl _make_fcontext
.align 2
_make_fcontext:
; save return address into R6
mflr r6
; first arg of make_fcontext() == top address of context-function
; shift address in R3 to lower 16 byte boundary
clrrwi r3, r3, 4
; reserve space for context-data on context-stack
; including 64 byte of linkage + parameter area (R1 % 16 == 0)
subi r3, r3, 336
; third arg of make_fcontext() == address of context-function
; store as trampoline's R31
stw r5, 224(r3)
; set back-chain to zero
li r0, 0
stw r0, 244(r3)
mffs f0 ; load FPSCR
stfd f0, 144(r3) ; save FPSCR
; compute address of returned transfer_t
addi r0, r3, 252
mr r4, r0
stw r4, 228(r3)
; load LR
mflr r0
; jump to label 1
bcl 20, 31, L1
L1:
; load LR into R4
mflr r4
; compute abs address of trampoline, use as PC
addi r5, r4, lo16(Ltrampoline - L1)
stw r5, 240(r3)
; compute abs address of label finish
addi r4, r4, lo16(Lfinish - L1)
; restore LR
mtlr r0
; save address of finish as return-address for context-function
; will be entered after context-function returns
stw r4, 236(r3)
; restore return address from R6
mtlr r6
blr ; return pointer to context-data
Ltrampoline:
; We get R31 = context-function, R3 = address of transfer_t,
; but we need to pass R3:R4 = transfer_t.
mtctr r31
lwz r4, 4(r3)
lwz r3, 0(r3)
bctr
Lfinish:
; load address of _exit into CTR
bcl 20, 31, L2
L2:
mflr r4
addis r4, r4, ha16(Lexitp - L2)
lwz r4, lo16(Lexitp - L2)(r4)
mtctr r4
; exit code is zero
li r3, 0
; exit application
bctr
.const_data
.align 2
Lexitp:
.long __exit
|
