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[/] [mips32r1/] [trunk/] [Software/] [demos/] [XD5_Threads/] [src/] [os/] [kernel.asm] - Blame information for rev 2

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Line No.	Rev	Author	Line
1	2	ayersg	`###############################################################################`
2			`# TITLE: Thread kernel demo`
3			`# AUTHOR: Grant Ayers (ayers@cs.utah.edu)`
4			`# DATE: 30 June 2012`
5			`# FILENAME: kernel.asm`
6			`# PROJECT: University of Utah XUM Single Core`
7			`# DESCRIPTION:`
8			`# Switches between 8 simultaneously-running threads.`
9			`# Demonstrates interrupts and llsc atomic operations.`
10			`#`
11			`###############################################################################`
12
13
14			`.text`
15			`.balign 4`
16			`.global kernel`
17			`.ent kernel`
18			`.set noreorder`
19			`.set noat`
20			`kernel:`
21			`addiu $sp, $sp, -1152 # Room for 9*32 registers`
22
23			`# Set the stack pointer ($29) for each of 8 threads`
24			`lui $t0, 0x0007`
25			`ori $t0, $t0, 0x4000`
26			`sw $t0, 1140($sp)`
27			`addiu $t0, $t0, 0x4000`
28			`sw $t0, 1012($sp)`
29			`addiu $t0, $t0, 0x4000`
30			`sw $t0, 884($sp)`
31			`addiu $t0, $t0, 0x4000`
32			`sw $t0, 756($sp)`
33			`addiu $t0, $t0, 0x4000`
34			`sw $t0, 628($sp)`
35			`addiu $t0, $t0, 0x4000`
36			`sw $t0, 500($sp)`
37			`addiu $t0, $t0, 0x4000`
38			`sw $t0, 372($sp)`
39			`addiu $t0, $t0, 0x4000`
40			`sw $t0, 244($sp)`
41
42			`# Set the global pointer ($28) for each of 8 threads`
43			`sw $gp, 240($sp)`
44			`sw $gp, 368($sp)`
45			`sw $gp, 496($sp)`
46			`sw $gp, 624($sp)`
47			`sw $gp, 752($sp)`
48			`sw $gp, 880($sp)`
49			`sw $gp, 1008($sp)`
50			`sw $gp, 1136($sp)`
51
52			`# Set the EPC for each of 8 threads to start at main`
53			`lui $t0, main`
54			`ori $t0, $t0, main`
55			`sw $t0, 128($sp)`
56			`sw $t0, 256($sp)`
57			`sw $t0, 384($sp)`
58			`sw $t0, 512($sp)`
59			`sw $t0, 640($sp)`
60			`sw $t0, 768($sp)`
61			`sw $t0, 896($sp)`
62			`sw $t0, 1024($sp)`
63
64			`sw $zero, 0($sp) # Current thread stored in 0($sp)`
65			`mfc0 $k0, $12, 0 # Enable timer interrupt`
66			`ori $k0, $k0, 0x8000`
67			`mtc0 $k0, $12, 0`
68
69			`$wait:`
70			`j $wait # Wait for interrupt to begin schedule`
71			`nop`
72			`.end kernel`
73
74
75
76
77			`.global scheduler`
78			`.ent scheduler`
79			`scheduler:`
80			`addu $k0, $0, $sp # Recover the kernel stack pointer`
81			`la $sp, _sp`
82			`addiu $sp, $sp, -1152`
83			`sw $25, 4($sp) # Free four registers for use`
84			`sw $28, 8($sp)`
85			`sw $30, 12($sp)`
86			`sw $31, 16($sp)`
87			`lw $k1, 0($sp) # Current TID to k1`
88			`beq $k1, $zero, $skip_save # Don't save kernel's registers`
89			`nop`
90			`jal save_registers`
91			`nop`
92			`$skip_save:`
93			`lw $t0, 0($sp) # Increment TID`
94			`addiu $t0, $t0, 1`
95			`addiu $t1, $zero, 9 # Move TID back to 1 if it reaches 9`
96			`beq $t0, $t1, $reset_tid`
97			`nop`
98			`$tid_done:`
99			`sw $t0, 0($sp)`
100			`jal restore_registers # Load registers for next thread`
101			`nop`
102			`la $k1, _sp # Recover kernel stack pointer again`
103			`addiu $k1, $k1, -1152`
104			`lw $k1, 0($k1) # Load TID to k1 for main function`
105			`mfc0 $26, $9, 0 # Read Count to clear timer interrupt`
106			`eret # Run thread`
107			`$reset_tid:`
108			`addiu $t0, $zero, 1`
109			`j $tid_done`
110			`nop`
111			`.end scheduler`
112
113
114			`save_registers:`
115			`# Requires: k0 hold thread stack pointer`
116			`# k1 holds TID`
117			`# sp points to kernel stack`
118			`# Destroys:`
119
120			`# Find offset for register table in kernel space`
121			`addiu $25, $zero, 128`
122			`mul $25, $25, $k1`
123			`addu $25, $25, $sp`
124
125			`# Store thread stack pointer`
126			`sw $k0, 116($25)`
127			`addu $k0, $0, $25`
128
129			`# Store EPC from CP0`
130			`mfc0 $25, $14, 0`
131			`sw $25, 0($k0)`
132
133			`# Store remaining registers`
134			`sw $1, 4($k0)`
135			`sw $2, 8($k0)`
136			`sw $3, 12($k0)`
137			`sw $4, 16($k0)`
138			`sw $5, 20($k0)`
139			`sw $6, 24($k0)`
140			`sw $7, 28($k0)`
141			`sw $8, 32($k0)`
142			`sw $9, 36($k0)`
143			`sw $10, 40($k0)`
144			`sw $11, 44($k0)`
145			`sw $12, 48($k0)`
146			`sw $13, 52($k0)`
147			`sw $14, 56($k0)`
148			`sw $15, 60($k0)`
149			`sw $16, 64($k0)`
150			`sw $17, 68($k0)`
151			`sw $18, 72($k0)`
152			`sw $19, 76($k0)`
153			`sw $20, 80($k0)`
154			`sw $21, 84($k0)`
155			`sw $22, 88($k0)`
156			`sw $23, 92($k0)`
157			`sw $24, 96($k0)`
158			`lw $25, 4($sp)`
159			`sw $25, 100($k0)`
160			`lw $28, 8($sp)`
161			`sw $28, 112($k0)`
162			`lw $30, 12($sp)`
163			`sw $30, 120($k0)`
164			`addu $k1, $0, $31`
165			`lw $31, 16($sp)`
166			`sw $31, 124($k0)`
167			`jr $k1`
168			`nop`
169
170
171			`restore_registers:`
172			`# Requires: t0 specifies which thread (1-8)`
173			`# sp points to kernel stack`
174			`# Destroys: All registers`
175
176			`# Find offset for register table in kernel space`
177			`addiu $k1, $zero, 128`
178			`mul $k0, $t0, $k1`
179			`addu $k0, $k0, $sp`
180
181
182			`# Load EPC to CP0`
183			`lw $k1, 0($k0)`
184			`mtc0 $k1, $14, 0`
185			`# Load remaining registers`
186			`lw $1, 4($k0)`
187			`lw $2, 8($k0)`
188			`lw $3, 12($k0)`
189			`lw $4, 16($k0)`
190			`lw $5, 20($k0)`
191			`lw $6, 24($k0)`
192			`lw $7, 28($k0)`
193			`lw $8, 32($k0)`
194			`lw $9, 36($k0)`
195			`lw $10, 40($k0)`
196			`lw $11, 44($k0)`
197			`lw $12, 48($k0)`
198			`lw $13, 52($k0)`
199			`lw $14, 56($k0)`
200			`lw $15, 60($k0)`
201			`lw $16, 64($k0)`
202			`lw $17, 68($k0)`
203			`lw $18, 72($k0)`
204			`lw $19, 76($k0)`
205			`lw $20, 80($k0)`
206			`lw $21, 84($k0)`
207			`lw $22, 88($k0)`
208			`lw $23, 92($k0)`
209			`lw $24, 96($k0)`
210			`lw $25, 100($k0)`
211			`lw $28, 112($k0)`
212			`lw $29, 116($k0)`
213			`lw $30, 120($k0)`
214			`addu $k1, $0, $31`
215			`lw $31, 124($k0)`
216			`jr $k1`
217			`nop`
218

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[/] [mips32r1/] [trunk/] [Software/] [demos/] [XD5_Threads/] [src/] [os/] [kernel.asm] - Blame information for rev 2