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view target-utils/libcommon/serio.S @ 125:17c1e2a38418

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target-utils command input: don't emit BEL on error conditions with the new binary-safe fc-iram these BELs get printed as ^G
author Michael Spacefalcon <msokolov@ivan.Harhan.ORG>
date Thu, 31 Oct 2013 07:15:32 +0000
parents 40f607bb0a2c
children d7591faa1258
line wrap: on
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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
	mvneq	r0, #1
	bxeq	lr
	ldrb	r0, [r2, #NS16550_RBR]
	bx	lr