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.syntax unified
.cpu cortex-m0plus
.thumb
.equ UART0_BASE, 0x40034000
.equ UARTDR_OFST, 0x00
.equ UARTFR_OFST, 0x18
.type uart_send, %function
.global uart_send
uart_send:
ldr r1, =UART0_BASE
movs r3, 0b1 << 5 // TX FIFO full
1:
ldr r2, [r1, UARTFR_OFST]
tst r2, r3
bne 1b
strb r0, [r1, UARTDR_OFST]
bx lr
.type uart_recv, %function
.global uart_recv
uart_recv:
ldr r1, =UART0_BASE
movs r3, 0b1 << 4 // RX FIFO empty
1:
ldr r2, [r1, UARTFR_OFST]
tst r2, r3
bne 1b
ldrb r0, [r1, UARTDR_OFST]
bx lr
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