xref: /openbmc/linux/arch/arm/kernel/debug.S (revision 1da177e4)
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#include <asm/hardware.h>
15
16		.text
17
18/*
19 * Some debugging routines (useful if you've got MM problems and
20 * printk isn't working).  For DEBUGGING ONLY!!!  Do not leave
21 * references to these in a production kernel!
22 */
23
24#if defined(CONFIG_DEBUG_ICEDCC)
25		@@ debug using ARM EmbeddedICE DCC channel
26		.macro	addruart, rx
27		.endm
28
29		.macro	senduart, rd, rx
30		mcr	p14, 0, \rd, c1, c0, 0
31		.endm
32
33		.macro	busyuart, rd, rx
341001:
35		mrc	p14, 0, \rx, c0, c0, 0
36		tst	\rx, #2
37		beq	1001b
38
39		.endm
40
41		.macro	waituart, rd, rx
42		mov	\rd, #0x2000000
431001:
44		subs	\rd, \rd, #1
45		bmi	1002f
46		mrc	p14, 0, \rx, c0, c0, 0
47		tst	\rx, #2
48		bne	1001b
491002:
50		.endm
51#else
52#include <asm/arch/debug-macro.S>
53#endif
54
55/*
56 * Useful debugging routines
57 */
58ENTRY(printhex8)
59		mov	r1, #8
60		b	printhex
61
62ENTRY(printhex4)
63		mov	r1, #4
64		b	printhex
65
66ENTRY(printhex2)
67		mov	r1, #2
68printhex:	adr	r2, hexbuf
69		add	r3, r2, r1
70		mov	r1, #0
71		strb	r1, [r3]
721:		and	r1, r0, #15
73		mov	r0, r0, lsr #4
74		cmp	r1, #10
75		addlt	r1, r1, #'0'
76		addge	r1, r1, #'a' - 10
77		strb	r1, [r3, #-1]!
78		teq	r3, r2
79		bne	1b
80		mov	r0, r2
81		b	printascii
82
83		.ltorg
84
85ENTRY(printascii)
86		addruart r3
87		b	2f
881:		waituart r2, r3
89		senduart r1, r3
90		busyuart r2, r3
91		teq	r1, #'\n'
92		moveq	r1, #'\r'
93		beq	1b
942:		teq	r0, #0
95		ldrneb	r1, [r0], #1
96		teqne	r1, #0
97		bne	1b
98		mov	pc, lr
99
100ENTRY(printch)
101		addruart r3
102		mov	r1, r0
103		mov	r0, #0
104		b	1b
105
106hexbuf:		.space 16
107