xref: /openbmc/linux/arch/arm/kernel/debug.S (revision 4f6cce39)
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#include <asm/assembler.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_SEMIHOSTING)
24#include CONFIG_DEBUG_LL_INCLUDE
25#endif
26
27#ifdef CONFIG_MMU
28		.macro	addruart_current, rx, tmp1, tmp2
29		addruart	\tmp1, \tmp2, \rx
30		mrc		p15, 0, \rx, c1, c0
31		tst		\rx, #1
32		moveq		\rx, \tmp1
33		movne		\rx, \tmp2
34		.endm
35
36#else /* !CONFIG_MMU */
37		.macro	addruart_current, rx, tmp1, tmp2
38		addruart	\rx, \tmp1, \tmp2
39		.endm
40
41#endif /* CONFIG_MMU */
42
43/*
44 * Useful debugging routines
45 */
46ENTRY(printhex8)
47		mov	r1, #8
48		b	printhex
49ENDPROC(printhex8)
50
51ENTRY(printhex4)
52		mov	r1, #4
53		b	printhex
54ENDPROC(printhex4)
55
56ENTRY(printhex2)
57		mov	r1, #2
58printhex:	adr	r2, hexbuf
59		add	r3, r2, r1
60		mov	r1, #0
61		strb	r1, [r3]
621:		and	r1, r0, #15
63		mov	r0, r0, lsr #4
64		cmp	r1, #10
65		addlt	r1, r1, #'0'
66		addge	r1, r1, #'a' - 10
67		strb	r1, [r3, #-1]!
68		teq	r3, r2
69		bne	1b
70		mov	r0, r2
71		b	printascii
72ENDPROC(printhex2)
73
74hexbuf:		.space 16
75
76		.ltorg
77
78#ifndef CONFIG_DEBUG_SEMIHOSTING
79
80ENTRY(printascii)
81		addruart_current r3, r1, r2
82		b	2f
831:		waituart r2, r3
84		senduart r1, r3
85		busyuart r2, r3
86		teq	r1, #'\n'
87		moveq	r1, #'\r'
88		beq	1b
892:		teq	r0, #0
90		ldrneb	r1, [r0], #1
91		teqne	r1, #0
92		bne	1b
93		ret	lr
94ENDPROC(printascii)
95
96ENTRY(printch)
97		addruart_current r3, r1, r2
98		mov	r1, r0
99		mov	r0, #0
100		b	1b
101ENDPROC(printch)
102
103#ifdef CONFIG_MMU
104ENTRY(debug_ll_addr)
105		addruart r2, r3, ip
106		str	r2, [r0]
107		str	r3, [r1]
108		ret	lr
109ENDPROC(debug_ll_addr)
110#endif
111
112#else
113
114ENTRY(printascii)
115		mov	r1, r0
116		mov	r0, #0x04		@ SYS_WRITE0
117	ARM(	svc	#0x123456	)
118	THUMB(	svc	#0xab		)
119		ret	lr
120ENDPROC(printascii)
121
122ENTRY(printch)
123		adr	r1, hexbuf
124		strb	r0, [r1]
125		mov	r0, #0x03		@ SYS_WRITEC
126	ARM(	svc	#0x123456	)
127	THUMB(	svc	#0xab		)
128		ret	lr
129ENDPROC(printch)
130
131ENTRY(debug_ll_addr)
132		mov	r2, #0
133		str	r2, [r0]
134		str	r2, [r1]
135		ret	lr
136ENDPROC(debug_ll_addr)
137
138#endif
139