xref: /linux/arch/arm/kernel/debug.S (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1/*
2 *  linux/arch/arm/kernel/debug.S
3 *
4 *  Copyright (C) 1994-1999 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 *  32-bit debugging code
11 */
12#include <linux/linkage.h>
13
14		.text
15
16/*
17 * Some debugging routines (useful if you've got MM problems and
18 * printk isn't working).  For DEBUGGING ONLY!!!  Do not leave
19 * references to these in a production kernel!
20 */
21
22#if defined(CONFIG_DEBUG_ICEDCC)
23		@@ debug using ARM EmbeddedICE DCC channel
24		.macro	addruart, rx
25		.endm
26
27		.macro	senduart, rd, rx
28		mcr	p14, 0, \rd, c1, c0, 0
29		.endm
30
31		.macro	busyuart, rd, rx
321001:
33		mrc	p14, 0, \rx, c0, c0, 0
34		tst	\rx, #2
35		beq	1001b
36
37		.endm
38
39		.macro	waituart, rd, rx
40		mov	\rd, #0x2000000
411001:
42		subs	\rd, \rd, #1
43		bmi	1002f
44		mrc	p14, 0, \rx, c0, c0, 0
45		tst	\rx, #2
46		bne	1001b
471002:
48		.endm
49#else
50#include <asm/arch/debug-macro.S>
51#endif
52
53/*
54 * Useful debugging routines
55 */
56ENTRY(printhex8)
57		mov	r1, #8
58		b	printhex
59
60ENTRY(printhex4)
61		mov	r1, #4
62		b	printhex
63
64ENTRY(printhex2)
65		mov	r1, #2
66printhex:	adr	r2, hexbuf
67		add	r3, r2, r1
68		mov	r1, #0
69		strb	r1, [r3]
701:		and	r1, r0, #15
71		mov	r0, r0, lsr #4
72		cmp	r1, #10
73		addlt	r1, r1, #'0'
74		addge	r1, r1, #'a' - 10
75		strb	r1, [r3, #-1]!
76		teq	r3, r2
77		bne	1b
78		mov	r0, r2
79		b	printascii
80
81		.ltorg
82
83ENTRY(printascii)
84		addruart r3
85		b	2f
861:		waituart r2, r3
87		senduart r1, r3
88		busyuart r2, r3
89		teq	r1, #'\n'
90		moveq	r1, #'\r'
91		beq	1b
922:		teq	r0, #0
93		ldrneb	r1, [r0], #1
94		teqne	r1, #0
95		bne	1b
96		mov	pc, lr
97
98ENTRY(printch)
99		addruart r3
100		mov	r1, r0
101		mov	r0, #0
102		b	1b
103
104hexbuf:		.space 16
105