FreeCalypso > hg > freecalypso-sw
view target-utils/libcommon/serio.S @ 484:c617a6adcb69
top level README: status update
author | Michael Spacefalcon <msokolov@ivan.Harhan.ORG> |
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date | Sun, 29 Jun 2014 19:05:52 +0000 |
parents | d7591faa1258 |
children |
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#include "ns16550.h" @ this module implements the elementary serial I/O operations .text .code 32 .global serial_out serial_out: ldr r1, =uart_base ldr r2, [r1] 1: ldrb r3, [r2, #NS16550_LSR] tst r3, #NS16550_LSR_THRE beq 1b strb r0, [r2, #NS16550_THR] bx lr .global serial_in_poll serial_in_poll: ldr r1, =uart_base ldr r2, [r1] ldrb r3, [r2, #NS16550_LSR] tst r3, #NS16550_LSR_DR ldrneb r0, [r2, #NS16550_RBR] mvneq r0, #0 bx lr .global serial_flush serial_flush: ldr r1, =uart_base ldr r2, [r1] 1: ldrb r3, [r2, #NS16550_LSR] tst r3, #NS16550_LSR_TEMP beq 1b bx lr