/
lib.s
90 lines (84 loc) · 1.03 KB
/
lib.s
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mtime = 0x1000000
mtimecmp = 0x1000008
.text
.globl _start
_start:
li sp,0x3000
call ttyinit
li t1,1<<11
csrs mie, t1
lla t1,trap
csrw mtvec,t1
csrsi mstatus,8
call main
ebreak
.globl writestr
writestr:
addi sp,sp,-16
sw ra,12(sp)
sw s1,8(sp)
mv s1,a0
1:
lbu a0,(s1)
beqz a0,2f
call writechar
addi s1,s1,1
j 1b
2:
lw s1,8(sp)
lw ra,12(sp)
addi sp,sp,16
ret
.globl writenum
writenum:
addi sp,sp,-16
sw ra,12(sp)
sw s1,8(sp)
sw s2,4(sp)
mv s1,a0
bgez s1,1f
li a0,'-'
call writechar
neg s1,s1
1:
li s2,1
li t1,10
mv t2,s1
2:
blt t2,t1,3f
mul s2,t1,s2
div t2,t2,t1
j 2b
3:
div t2,s1,s2
rem a0,t2,t1
addi a0,a0,'0'
call writechar
li t1,10
div s2,s2,t1
bgtz s2,3b
lw s2,4(sp)
lw s1,8(sp)
lw ra,12(sp)
addi sp,sp,16
ret
.globl enable_timer
enable_timer:
li t0,1<<7
csrs mie,t0
ret
.globl set_timer
set_timer:
lui t0,%hi(timer_proc)
addi t0,t0,%lo(timer_proc)
sw a1,(t0)
li t0,mtime
lw t1,(t0)
add t1,t1,a0
li t0,mtimecmp
sw t1,(t0)
ret
.bss
.globl timer_proc
timer_proc:
.skip 4