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
|
/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*/
#include <sbi/riscv_encoding.h>
#define __ASM_STR(x) x
#if __riscv_xlen == 64
#define __REG_SEL(a, b) __ASM_STR(a)
#define RISCV_PTR .dword
#elif __riscv_xlen == 32
#define __REG_SEL(a, b) __ASM_STR(b)
#define RISCV_PTR .word
#else
#error "Unexpected __riscv_xlen"
#endif
#define REG_L __REG_SEL(ld, lw)
#define REG_S __REG_SEL(sd, sw)
.section .entry, "ax", %progbits
.align 3
.globl _start
_start:
/* Pick one hart to run the main boot sequence */
lla a3, _hart_lottery
li a2, 1
amoadd.w a3, a2, (a3)
bnez a3, _start_hang
/* Save a0 and a1 */
lla a3, _boot_a0
REG_S a0, 0(a3)
lla a3, _boot_a1
REG_S a1, 0(a3)
/* Zero-out BSS */
lla a4, _bss_start
lla a5, _bss_end
_bss_zero:
REG_S zero, (a4)
add a4, a4, __SIZEOF_POINTER__
blt a4, a5, _bss_zero
_start_warm:
/* Disable and clear all interrupts */
csrw CSR_SIE, zero
csrw CSR_SIP, zero
/* Setup exception vectors */
lla a3, _start_hang
csrw CSR_STVEC, a3
/* Setup stack */
lla a3, _payload_end
li a4, 0x2000
add sp, a3, a4
/* Jump to C main */
lla a3, _boot_a0
REG_L a0, 0(a3)
lla a3, _boot_a1
REG_L a1, 0(a3)
call test_main
/* We don't expect to reach here hence just hang */
j _start_hang
.section .entry, "ax", %progbits
.align 3
.globl _start_hang
_start_hang:
wfi
j _start_hang
.section .entry, "ax", %progbits
.align 3
_hart_lottery:
RISCV_PTR 0
_boot_a0:
RISCV_PTR 0
_boot_a1:
RISCV_PTR 0
|