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
|
#include "pcr.h"
#ifdef __riscv64
# define STORE sd
# define LOAD ld
# define REGBYTES 8
#else
# define STORE sw
# define LOAD lw
# define REGBYTES 4
#endif
.text
save_tf: # write the trap frame onto the stack
# save gprs
STORE x3,3*REGBYTES(x2)
STORE x4,4*REGBYTES(x2)
STORE x5,5*REGBYTES(x2)
STORE x6,6*REGBYTES(x2)
STORE x7,7*REGBYTES(x2)
STORE x8,8*REGBYTES(x2)
STORE x9,9*REGBYTES(x2)
STORE x10,10*REGBYTES(x2)
STORE x11,11*REGBYTES(x2)
STORE x12,12*REGBYTES(x2)
STORE x13,13*REGBYTES(x2)
STORE x14,14*REGBYTES(x2)
STORE x15,15*REGBYTES(x2)
STORE x16,16*REGBYTES(x2)
STORE x17,17*REGBYTES(x2)
STORE x18,18*REGBYTES(x2)
STORE x19,19*REGBYTES(x2)
STORE x20,20*REGBYTES(x2)
STORE x21,21*REGBYTES(x2)
STORE x22,22*REGBYTES(x2)
STORE x23,23*REGBYTES(x2)
STORE x24,24*REGBYTES(x2)
STORE x25,25*REGBYTES(x2)
STORE x26,26*REGBYTES(x2)
STORE x27,27*REGBYTES(x2)
STORE x28,28*REGBYTES(x2)
STORE x29,29*REGBYTES(x2)
STORE x30,30*REGBYTES(x2)
STORE x31,31*REGBYTES(x2)
mfpcr x3,ASM_CR(PCR_K0)
STORE x3,1*REGBYTES(x2) # x1 is in PCR_K0
mfpcr x3,ASM_CR(PCR_K1)
STORE x3,2*REGBYTES(x2) # x2 is in PCR_K1
# get sr, epc, badvaddr, cause
mfpcr x3,ASM_CR(PCR_SR) # sr
STORE x3,32*REGBYTES(x2)
mfpcr x4,ASM_CR(PCR_EPC) # epc
STORE x4,33*REGBYTES(x2)
mfpcr x3,ASM_CR(PCR_BADVADDR) # badvaddr
STORE x3,34*REGBYTES(x2)
mfpcr x3,ASM_CR(PCR_CAUSE) # cause
STORE x3,35*REGBYTES(x2)
# get faulting insn, if it wasn't a fetch-related trap
li x5, CAUSE_MISALIGNED_FETCH
li x6, CAUSE_FAULT_FETCH
beq x3, x5, 1f
beq x3, x6, 1f
lh x3,0(x4)
lh x4,2(x4)
sh x3, 36*REGBYTES(x2)
sh x4,2+36*REGBYTES(x2)
1:
ret
.globl pop_tf
pop_tf: # write the trap frame onto the stack
# restore gprs
LOAD t0,32*REGBYTES(a0) # restore sr (should disable interrupts)
mtpcr t0,ASM_CR(PCR_SR)
LOAD x1,1*REGBYTES(a0)
mtpcr x1,ASM_CR(PCR_K0)
LOAD x1,2*REGBYTES(a0)
mtpcr x1,ASM_CR(PCR_K1)
move x1,a0
LOAD x3,3*REGBYTES(x1)
LOAD x4,4*REGBYTES(x1)
LOAD x5,5*REGBYTES(x1)
LOAD x6,6*REGBYTES(x1)
LOAD x7,7*REGBYTES(x1)
LOAD x8,8*REGBYTES(x1)
LOAD x9,9*REGBYTES(x1)
LOAD x10,10*REGBYTES(x1)
LOAD x11,11*REGBYTES(x1)
LOAD x12,12*REGBYTES(x1)
LOAD x13,13*REGBYTES(x1)
LOAD x14,14*REGBYTES(x1)
LOAD x15,15*REGBYTES(x1)
LOAD x16,16*REGBYTES(x1)
LOAD x17,17*REGBYTES(x1)
LOAD x18,18*REGBYTES(x1)
LOAD x19,19*REGBYTES(x1)
LOAD x20,20*REGBYTES(x1)
LOAD x21,21*REGBYTES(x1)
LOAD x22,22*REGBYTES(x1)
LOAD x23,23*REGBYTES(x1)
LOAD x24,24*REGBYTES(x1)
LOAD x25,25*REGBYTES(x1)
LOAD x26,26*REGBYTES(x1)
LOAD x27,27*REGBYTES(x1)
LOAD x28,28*REGBYTES(x1)
LOAD x29,29*REGBYTES(x1)
LOAD x30,30*REGBYTES(x1)
LOAD x31,31*REGBYTES(x1)
# gtfo!
LOAD x2,33*REGBYTES(x1)
mtpcr x2,ASM_CR(PCR_EPC)
mfpcr x1,ASM_CR(PCR_K0)
mfpcr x2,ASM_CR(PCR_K1)
eret
.global trap_entry
trap_entry:
mtpcr ra,ASM_CR(PCR_K0)
mtpcr x2,ASM_CR(PCR_K1)
# when coming from kernel, continue below its stack
mfpcr ra,ASM_CR(PCR_SR)
and ra,ra,SR_PS
add x2, sp, -320
bnez ra, 1f
la x2,stack_top-320
1:jal save_tf
move sp,x2
move a0,x2
jal handle_trap
.bss
.global stack_bot
.global stack_top
stack_bot:
.skip 4096
stack_top:
|
