Mr-Bossman_KISC-V/source/src/system_start.S

.section .asm, "ax"
.global _start
.global _exit_

#define STORE_REGS(reg) sw x##reg, ((reg*4)+0x10)(x0)
#define LOAD_REGS(reg) lw x##reg, ((reg*4)+0x10)(x0)

.align 4
	j _init
interrupt:
	.word _start
reason_code:
	.word 0x00
reg_store:
	.fill 32, 4
_exit_:
	.word 0x00
back:
	.word 1
_start:
	STORE_REGS(1)
	STORE_REGS(2)
	STORE_REGS(3)
	STORE_REGS(4)
	STORE_REGS(5)
	STORE_REGS(6)
	STORE_REGS(7)
	STORE_REGS(8)
	STORE_REGS(9)
	STORE_REGS(10)
	STORE_REGS(11)
	STORE_REGS(12)
	STORE_REGS(13)
	STORE_REGS(14)
	STORE_REGS(15)
	STORE_REGS(16)
	STORE_REGS(17)
	STORE_REGS(18)
	STORE_REGS(19)
	STORE_REGS(20)
	STORE_REGS(21)
	STORE_REGS(22)
	STORE_REGS(23)
	STORE_REGS(24)
	STORE_REGS(25)
	STORE_REGS(26)
	STORE_REGS(27)
	STORE_REGS(28)
	STORE_REGS(29)
	STORE_REGS(30)
	STORE_REGS(31)
	la	sp, _sstack
	addi	sp,sp,-16
	jal ra, entry
	LOAD_REGS(1)
	LOAD_REGS(2)
	LOAD_REGS(3)
	LOAD_REGS(4)
	LOAD_REGS(5)
	LOAD_REGS(6)
	LOAD_REGS(7)
	LOAD_REGS(8)
	LOAD_REGS(9)
	LOAD_REGS(10)
	LOAD_REGS(11)
	LOAD_REGS(12)
	LOAD_REGS(13)
	LOAD_REGS(14)
	LOAD_REGS(15)
	LOAD_REGS(16)
	LOAD_REGS(17)
	LOAD_REGS(18)
	LOAD_REGS(19)
	LOAD_REGS(20)
	LOAD_REGS(21)
	LOAD_REGS(22)
	LOAD_REGS(23)
	LOAD_REGS(24)
	LOAD_REGS(25)
	LOAD_REGS(26)
	LOAD_REGS(27)
	LOAD_REGS(28)
	LOAD_REGS(29)
	LOAD_REGS(30)
	LOAD_REGS(31)
	j back
_init:
	la x5, _start
	sw x5, 4(x0)
	li x1, 0x1800
	csrrw x0, mstatus, x1
	la x11, 0x10000000
	li x1, 0x80
	sb x1, 3(x11)
	li x1, 2
	sb x1, 0(x11)
	li x1, 3
	sb x1, 3(x11)
	la	sp, _sstack
	addi	sp,sp,-16
	jal ra, _boot_
	mv x1,x0
	mv x2,x0
	mv x3,x0
	mv x4,x0
	mv x5,x0
	mv x6,x0
	mv x7,x0
	mv x8,x0
	mv x9,x0
	mv x10,x0
	mv x11,x0
	mv x12,x0
	mv x13,x0
	mv x14,x0
	mv x15,x0
	mv x16,x0
	mv x17,x0
	mv x18,x0
	mv x19,x0
	mv x20,x0
	mv x21,x0
	mv x22,x0
	mv x23,x0
	mv x24,x0
	mv x25,x0
	mv x26,x0
	mv x27,x0
	mv x28,x0
	mv x29,x0
	mv x30,x0
	mv x31,x0
	la x11,0x81000000
	la x1, 0x80000000
	sw x1, 0x4(x0)
	mv x1, x0
	j back