Files
kunlun/bb_cpu/startup/start_2.S
2024-09-28 14:24:04 +08:00

65 lines
1.0 KiB
ArmAsm

// See LICENSE for license details.
#include "encoding.h"
.section .init
.globl _start_2
.type _start_2,@function
_start_2:
li t0, MSTATUS_MIE
csrc mstatus, t0
li t0, MIP_MTIP
csrc mie, t0
li t0, MIP_MEIP
csrc mie, t0
li t0, 0
csrc mcause, t0
la gp, _gp
la sp, _sp
/* bbcpu runs in RAM, so no data needs to copy. */
#if 0
/* 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:
#endif
/* 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:
/* init function*/
call _init_2
#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