.global _start
_start:
	li a1, 2
	csrs sstatus, a1
	la a1, _vec
	csrw stvec, a1
	li a7, 1
	la a1, _hello
	jal puts
	csrr a2, stvec
	jal putl
halt:
	j halt

putl:
	andi a0, a2, 0xf
	addi a0, a0, 0x30
	slti a1, a0, 0x3A
	bne a1, zero, _next
	addi a0, a0, 7
_next:
	ecall
	srli a2, a2, 4
	beq a2, zero, exit2
	j putl
exit2:
	li a0, 0xa
	ecall
	ret

puts:
	lb a0, (a1)
	beq a0, zero, exit
	ecall
	addi a1, a1, 1
	j puts
exit:
	ret

_hello:
.ascii "Hello, world!\n"
.byte 0

.align 8
_vec:
	li a7, 1
	la a1, _exception
	jal puts
	csrr a2, scause
	call putl
loop2:
	j loop2

_exception:
.ascii "exception\n"
.byte 0