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
|
.global crtStart
.global main
.global irqCallback
crtStart:
j crtInit
nop
nop
nop
nop
nop
nop
nop
.global trap_entry
trap_entry:
sw x1, - 1*4(sp)
sw x5, - 2*4(sp)
sw x6, - 3*4(sp)
sw x7, - 4*4(sp)
sw x10, - 5*4(sp)
sw x11, - 6*4(sp)
sw x12, - 7*4(sp)
sw x13, - 8*4(sp)
sw x14, - 9*4(sp)
sw x15, -10*4(sp)
sw x16, -11*4(sp)
sw x17, -12*4(sp)
sw x28, -13*4(sp)
sw x29, -14*4(sp)
sw x30, -15*4(sp)
sw x31, -16*4(sp)
addi sp,sp,-16*4
call irqCallback
lw x1 , 15*4(sp)
lw x5, 14*4(sp)
lw x6, 13*4(sp)
lw x7, 12*4(sp)
lw x10, 11*4(sp)
lw x11, 10*4(sp)
lw x12, 9*4(sp)
lw x13, 8*4(sp)
lw x14, 7*4(sp)
lw x15, 6*4(sp)
lw x16, 5*4(sp)
lw x17, 4*4(sp)
lw x28, 3*4(sp)
lw x29, 2*4(sp)
lw x30, 1*4(sp)
lw x31, 0*4(sp)
addi sp,sp,16*4
mret
.text
crtInit:
.option push
.option norelax
la gp, __global_pointer$
.option pop
la sp, _stack_start
bss_init:
la a0, _bss_start
la a1, _bss_end
bss_loop:
beq a0,a1,bss_done
sw zero,0(a0)
add a0,a0,4
j bss_loop
bss_done:
ctors_init:
la a0, _ctors_start
addi sp,sp,-4
ctors_loop:
la a1, _ctors_end
beq a0,a1,ctors_done
lw a3,0(a0)
add a0,a0,4
sw a0,0(sp)
jalr a3
lw a0,0(sp)
j ctors_loop
ctors_done:
addi sp,sp,4
//li a0, 0x880 //880 enable timer + external interrupts
//csrw mie,a0
//li a0, 0x1808 //1808 enable interrupts
//csrw mstatus,a0
call main
infinitLoop:
j infinitLoop
|
