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.section ".text"
.globl uart_char
uart_char:
mov r2, #0x1000
movt r2, #0x3f20
uart_char.loop:
ldr r3, [r2, #24]
tst r3, #0b100000
bne uart_char.loop
str r0, [r2]
bx lr
.globl uart_string
uart_string:
push {r4, lr}
mov r4, r0
ldrb r0, [r0]
cmp r0, #0
popeq {r4, pc}
uart_string.loop:
bl uart_char
ldrb r0, [r4, #1]!
cmp r0, #0
bne uart_string.loop
pop {r4, pc}
.globl uart_hex
uart_hex:
push {r4, lr}
mov r2, #0x1000
movt r2, #0x3f20
uart_hex.loop:
ldr r3, [r2, #24]
tst r3, #0b100000
bne uart_hex.loop
mov r3, #7
uart_hex.hloop:
mov r1, r0
asr r1, r3
asr r1, r3
asr r1, r3
asr r1, r3
and r1, #0xf
add r1, #0x30
cmp r1, #0x3A
blt uart_hex.print
add r1, #7
uart_hex.print:
str r1, [r2]
subs r3, #1
bge uart_hex.hloop
pop {r4, pc}
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