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hal_switch.S @ 446

Last change on this file since 446 was 408, checked in by alain, 7 years ago
Fix several bugs in the fork() syscall.
File size: 7.5 KB

Line
1	/*
2	* hal_witch.S - CPU context switch function for TSAR-MIPS32
3	*
4	* Author Alain Greiner (2016)
5	*
6	* Copyright (c) UPMC Sorbonne Universites
7	*
8	* This file is part of ALMOS-MKH.
9	*
10	* ALMOS-MKH.is free software; you can redistribute it and/or modify it
11	* under the terms of the GNU General Public License as published by
12	* the Free Software Foundation; version 2.0 of the License.
13	*
14	* ALMOS-MKH.is distributed in the hope that it will be useful, but
15	* WITHOUT ANY WARRANTY; without even the implied warranty of
16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17	* General Public License for more details.
18	*
19	* You should have received a copy of the GNU General Public License
20	* along with ALMOS-MKH.; if not, write to the Free Software Foundation,
21	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22	*/
23
24	.section .switch , "ax" , @progbits
25
26	.global hal_do_cpu_switch
27	.global hal_do_cpu_save
28
29	.set noat
30	.set noreorder
31
32	#---------------------------------------------------------------------------------
33	# The hal_do_cpu_switch() function makes the following assumptions:
34	# - register $4 contains a pointer on the old thread context.
35	# - register $5 contains a pointer on the new thread context.
36	#---------------------------------------------------------------------------------
37	hal_do_cpu_switch:
38
39	/* save old thread context */
40
41	move $26, $4 /* $26 <= ctx_old */
42
43	mfc0 $27, $14
44	sw $27, 04($26) / save c0_epc to slot 0 */
45
46	sw $1, 1*4($26)
47	sw $2, 2*4($26)
48	sw $3, 3*4($26)
49	sw $4, 4*4($26)
50	sw $5, 5*4($26)
51	sw $6, 6*4($26)
52	sw $7, 7*4($26)
53	sw $8, 8*4($26)
54	sw $9, 9*4($26)
55	sw $10, 10*4($26)
56	sw $11, 11*4($26)
57	sw $12, 12*4($26)
58	sw $13, 13*4($26)
59	sw $14, 14*4($26)
60	sw $15, 15*4($26)
61	sw $16, 16*4($26)
62	sw $17, 17*4($26)
63	sw $18, 18*4($26)
64	sw $19, 19*4($26)
65	sw $20, 20*4($26)
66	sw $21, 21*4($26)
67	sw $22, 22*4($26)
68	sw $23, 23*4($26)
69	sw $24, 24*4($26)
70	sw $25, 25*4($26)
71
72	mfhi $27
73	sw $27, 264($26) / save hi to slot 26 */
74	mflo $27
75	sw $27, 274($26) / save lo to slot 27 */
76
77	sw $28, 28*4($26)
78	sw $29, 29*4($26)
79	sw $30, 30*4($26)
80	sw $31, 31*4($26)
81
82	mfc0 $27, $12
83	sw $27, 344($26) / save c0_sr to slot 34 */
84	mfc0 $27, $4, 2
85	sw $27, 354($26) / save c0_th to slot 35 */
86
87	mfc2 $27, $0
88	sw $27, 324($26) / save c2_ptpr to slot 32 */
89	mfc2 $27, $1
90	sw $27, 334($26) / save c2_mode to slot 33 */
91
92	/* restore new thread context */
93
94	move $26, $5 /* $26 <= ctx_new */
95
96	lw $27, 0*4($26)
97	mtc0 $27, $14 /* restore C0_epc from slot 0 */
98
99	lw $1, 1*4($26)
100	lw $2, 2*4($26)
101	lw $3, 3*4($26)
102	lw $4, 4*4($26)
103	lw $5, 5*4($26)
104	lw $6, 6*4($26)
105	lw $7, 7*4($26)
106	lw $8, 8*4($26)
107	lw $9, 9*4($26)
108	lw $10, 10*4($26)
109	lw $11, 11*4($26)
110	lw $12, 12*4($26)
111	lw $13, 13*4($26)
112	lw $14, 14*4($26)
113	lw $15, 15*4($26)
114	lw $16, 16*4($26)
115	lw $17, 17*4($26)
116	lw $18, 18*4($26)
117	lw $19, 19*4($26)
118	lw $20, 20*4($26)
119	lw $21, 21*4($26)
120	lw $22, 22*4($26)
121	lw $23, 23*4($26)
122	lw $24, 24*4($26)
123	lw $25, 25*4($26)
124
125	lw $27, 26*4($26)
126	mthi $27 /* restore hi from slot 26 */
127	lw $27, 27*4($26)
128	mtlo $27 /* restore lo from slot 27 */
129
130	lw $28, 28*4($26)
131	lw $29, 29*4($26)
132	lw $30, 30*4($26)
133	lw $31, 314($26) / restore ra from slot 31 */
134
135	lw $27, 32*4($26)
136	mtc2 $27, $0 /* restore c2_ptpr from slot 32 */
137
138	lw $27, 35*4($26)
139	mtc0 $27, $4, 2 /* restore c0_th from slot 35 */
140
141	lw $27, 33*4($26)
142	lw $26, 34*4($26)
143
144	mtc2 $27, $1 /* restore c2_mode from slot 33 */
145	mtc0 $26, $12 /* restore c0_sr from slot 34 */
146
147	sync
148
149	jr $31 /* return to caller */
150	nop
151
152	#---------------------------------------------------------------------------------
153	# The hal_do_cpu_save()function makes the following assumption:
154	# - register $4 contains a pointer on the target thread context.
155	#---------------------------------------------------------------------------------
156	hal_do_cpu_save:
157
158	move $26, $4 /* $26 <= &context */
159
160	mfc0 $27, $14
161	sw $27, 04($26) / save c0_epc to slot 0 */
162
163	sw $1, 1*4($26)
164	sw $2, 2*4($26)
165	sw $3, 3*4($26)
166	sw $4, 4*4($26)
167	sw $5, 5*4($26)
168	sw $6, 6*4($26)
169	sw $7, 7*4($26)
170	sw $8, 8*4($26)
171	sw $9, 9*4($26)
172	sw $10, 10*4($26)
173	sw $11, 11*4($26)
174	sw $12, 12*4($26)
175	sw $13, 13*4($26)
176	sw $14, 14*4($26)
177	sw $15, 15*4($26)
178	sw $16, 16*4($26)
179	sw $17, 17*4($26)
180	sw $18, 18*4($26)
181	sw $19, 19*4($26)
182	sw $20, 20*4($26)
183	sw $21, 21*4($26)
184	sw $22, 22*4($26)
185	sw $23, 23*4($26)
186	sw $24, 24*4($26)
187	sw $25, 25*4($26)
188
189	mfhi $27
190	sw $27, 264($26) / save hi to slot 26 */
191	mflo $27
192	sw $27, 274($26) / save lo to slot 27 */
193
194	sw $28, 284($26) / save gp to slot 28 */
195	sw $29, 294($26) / save sp to slot 29 */
196	sw $30, 304($26) / save s8 to slot 30 */
197	sw $31, 314($26) / save ra to slot 31 */
198
199	mfc2 $27, $0
200	sw $27, 324($26) / save c2_ptpr to slot 32 */
201	mfc2 $27, $1
202	sw $27, 334($26) / save c2_mode to slot 33 */
203	mfc0 $27, $12
204	sw $27, 344($26) / save c0_sr to slot 34 */
205	mfc0 $27, $4, 2
206	sw $27, 354($26) / save c0_th to slot 35 */
207
208	sync
209
210	jr $31 /* return to caller */
211	nop
212
213	.set reorder
214	.set at
215

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