view gsm-fw/libiram/bcopy_words.S @ 1023:cd6002e3aefb

doc/Freerunner-Howto: apparently some people still use SHR, so mention it too
author Mychaela Falconia <falcon@ivan.Harhan.ORG>
date Tue, 03 May 2016 13:48:39 +0000
parents cbc49d533b7d
children
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/*
 * bcopy_aligned_words() takes the same arguments as BSD bcopy(),
 * but requires both addresses and the count to be 32-bit word-aligned,
 * and assumes that the source and destination memory regions
 * do not overlap.  Furthermore, the count is expected to be non-zero.
 *
 * Arguments:
 *
 * R0: source address (word-aligned)
 * R1: destination address (ditto)
 * R2: byte count (must be a multiple of 4)
 */

	.text
	.code	32

	.globl	bcopy_aligned_words
bcopy_aligned_words:
1:	ldr	r3, [r0], #4
	str	r3, [r1], #4
	subs	r2, r2, #4
	bhi	1b
	bx	lr