Firmwares/demo_gpio/bsp/env/start.S

112 lines
1.5 KiB
ArmAsm

// See LICENSE for license details.
#include <sifive/smp.h>
/* This is defined in sifive/platform.h, but that can't be included from
* assembly. */
#define CLINT_CTRL_ADDR 0x02000000
.section .init
.globl _start
.type _start,@function
_start:
.cfi_startproc
.cfi_undefined ra
.option push
.option norelax
la gp, __global_pointer$
.option pop
la sp, _sp
#if defined(ENABLE_SMP)
smp_pause(t0, t1)
#endif
/* 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
#if defined(ENABLE_SMP)
smp_resume(t0, t1)
csrr a0, mhartid
bnez a0, 2f
#endif
auipc ra, 0
addi sp, sp, -16
#if __riscv_xlen == 32
sw ra, 8(sp)
#else
sd ra, 8(sp)
#endif
/* argc = argv = 0 */
li a0, 0
li a1, 0
call main
tail exit
1:
j 1b
#if defined(ENABLE_SMP)
2:
la t0, trap_entry
csrw mtvec, t0
csrr a0, mhartid
la t1, _sp
slli t0, a0, 10
sub sp, t1, t0
auipc ra, 0
addi sp, sp, -16
#if __riscv_xlen == 32
sw ra, 8(sp)
#else
sd ra, 8(sp)
#endif
call secondary_main
tail exit
1:
j 1b
#endif
.cfi_endproc