xref: /openbmc/linux/arch/arm/kernel/debug.S (revision de2fe5e0) 
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/config.h>
13#include <linux/linkage.h>
14
15		.text
16
17/*
18 * Some debugging routines (useful if you've got MM problems and
19 * printk isn't working).  For DEBUGGING ONLY!!!  Do not leave
20 * references to these in a production kernel!
21 */
22
23#if defined(CONFIG_DEBUG_ICEDCC)
24		@@ debug using ARM EmbeddedICE DCC channel
25		.macro	addruart, rx
26		.endm
27
28		.macro	senduart, rd, rx
29		mcr	p14, 0, \rd, c1, c0, 0
30		.endm
31
32		.macro	busyuart, rd, rx
331001:
34		mrc	p14, 0, \rx, c0, c0, 0
35		tst	\rx, #2
36		beq	1001b
37
38		.endm
39
40		.macro	waituart, rd, rx
41		mov	\rd, #0x2000000
421001:
43		subs	\rd, \rd, #1
44		bmi	1002f
45		mrc	p14, 0, \rx, c0, c0, 0
46		tst	\rx, #2
47		bne	1001b
481002:
49		.endm
50#else
51#include <asm/arch/debug-macro.S>
52#endif
53
54/*
55 * Useful debugging routines
56 */
57ENTRY(printhex8)
58		mov	r1, #8
59		b	printhex
60
61ENTRY(printhex4)
62		mov	r1, #4
63		b	printhex
64
65ENTRY(printhex2)
66		mov	r1, #2
67printhex:	adr	r2, hexbuf
68		add	r3, r2, r1
69		mov	r1, #0
70		strb	r1, [r3]
711:		and	r1, r0, #15
72		mov	r0, r0, lsr #4
73		cmp	r1, #10
74		addlt	r1, r1, #'0'
75		addge	r1, r1, #'a' - 10
76		strb	r1, [r3, #-1]!
77		teq	r3, r2
78		bne	1b
79		mov	r0, r2
80		b	printascii
81
82		.ltorg
83
84ENTRY(printascii)
85		addruart r3
86		b	2f
871:		waituart r2, r3
88		senduart r1, r3
89		busyuart r2, r3
90		teq	r1, #'\n'
91		moveq	r1, #'\r'
92		beq	1b
932:		teq	r0, #0
94		ldrneb	r1, [r0], #1
95		teqne	r1, #0
96		bne	1b
97		mov	pc, lr
98
99ENTRY(printch)
100		addruart r3
101		mov	r1, r0
102		mov	r0, #0
103		b	1b
104
105hexbuf:		.space 16
106