summaryrefslogtreecommitdiff
path: root/bsp/env/start.S
blob: e86105bda3c38a581fff2df5ddebe4e8d659062e (plain)
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
// See LICENSE for license details.

// See LICENSE for license details.

	.section .init
	.globl _start
	.type _start,@function

_start:
.option push
.option norelax
	la gp, __global_pointer$
.option pop
	la sp, _sp

	/* Load data section */
	la a0, _data_lma
	la a1, _data
	la a2, _edata
	bgeu a1, a2, 2f
1:
	lw t0, (a0)
	sw t0, (a1)
	addi a0, a0, 4
	addi a1, a1, 4
	bltu a1, a2, 1b
2:

	/* Clear bss section */
	la a0, __bss_start
	la a1, _end
	bgeu a0, a1, 2f
1:
	sw zero, (a0)
	addi a0, a0, 4
	bltu a0, a1, 1b
2:

	/* Call global constructors */
	la a0, __libc_fini_array
	call atexit
	call __libc_init_array

#ifndef __riscv_float_abi_soft
	/* Enable FPU */
	li t0, MSTATUS_FS
	csrs mstatus, t0
	csrr t1, mstatus
	and t1, t1, t0
	beqz t1, 1f
	fssr x0
1:
#endif

	/* argc = argv = 0 */
	li a0, 0
	li a1, 0
	call main
	tail exit

1:
	j 1b