aboutsummaryrefslogtreecommitdiff
path: root/contrib/loaders/flash/armv4_5_cfi_intel_8.s
blob: 18f4bb811cce01b9412bba30820287bae5514db6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
/* SPDX-License-Identifier: GPL-2.0-or-later */

/***************************************************************************
 *   Copyright (C) 2005, 2007 by Dominic Rath                              *
 *   Dominic.Rath@gmx.de                                                   *
 *   Copyright (C) 2010 Spencer Oliver                                     *
 *   spen@spen-soft.co.uk                                                  *
 ***************************************************************************/

	.text
	.arm
	.arch armv4

	.section .init

/* algorithm register usage:
 * r0: source address (in RAM)
 * r1: target address (in Flash)
 * r2: count
 * r3: flash write command
 * r4: status byte (returned to host)
 * r5: busy test pattern
 * r6: error test pattern
 */

loop:
	ldrb	r4, [r0], #1
	strb	r3, [r1]
	strb	r4, [r1]
busy:
	ldrb	r4, [r1]
	and		r7, r4, r5
	cmp		r7, r5
	bne		busy
	tst		r4, r6
	bne		done
	subs	r2, r2, #1
	beq		done
	add		r1, r1, #1
	b		loop
done:
	b		done

	.end