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.syntax unified
.cpu cortex-m0plus
.thumb
.equ IO_BANK0_BASE, 0x40014000
.equ GPIO25_STATUS, (IO_BANK0_BASE + 0x0c8)
.equ GPIO25_CTRL, (IO_BANK0_BASE + 0x0cc)
.equ SIO_BASE, 0xd0000000
.equ GPIO_OE_SET_OFST, 0x024
.equ GPIO_OUT_XOR_OFST, 0x01c
.equ ATOMIC_CLEAR, 0x3000
.type setup_led, %function
.global setup_led
setup_led:
ldr r1, =GPIO25_CTRL
movs r0, 5 // SIO function = 5
str r0, [r1, 0]
ldr r1, =SIO_BASE
movs r0, 1
lsls r0, r0, 25 // GPIO 25 (LED) output enable
str r0, [r1, GPIO_OE_SET_OFST]
bx lr
.type blink, %function
.global blink
blink:
movs r0, 1
lsls r0, 25
1:
str r0, [r1, GPIO_OUT_XOR_OFST]
bl delay_1s
b 1b
.type blinkN, %function
.global blinkN
blinkN:
push {lr}
movs r2, 1
lsls r2, 25
tst r0, r0
beq done
on_then_off:
str r2, [r1, GPIO_OUT_XOR_OFST]
bl delay_1s
str r2, [r1, GPIO_OUT_XOR_OFST]
bl delay_1s
subs r0, r0, 1
bne on_then_off
done:
pop {pc}
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