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.global reset
reset:
# Stop and reset timer
ldr r2, =0x30020000
mov r1, #(1 << 3)
str r1, [r2, #4]
mov r1, #0
str r1, [r2, #0]
# Enable timer interrupts
ldr r3, =0x30070000
ldr r1, =(1 << 0)
str r1, [r3, #4]
# Enable IRQs
mov r0, #0
mrs r1, cpsr
and r1, #~(1 << 7)
msr cpsr_c, r1
# Program timer with timeout value of 128 cycles
mov r1, #4
str r1, [r2, #8]
mov r1, #0
str r1, [r2, #12]
# Start timer
mov r1, #(1 << 0 | 1 << 2)
str r1, [r2, #4]
.wfi:
tst r0, r0
beq .wfi
mov r2, #2
mov pc, lr
.global irq
irq:
mov r0, #1
ldr r1, [r2, #0]
mov r4, #0
str r4, [r2, #0]
subs pc, lr, #4
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