xref: /openbmc/linux/arch/arm/kernel/debug.S (revision e3b9f1e8)
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_rel
59		ldr	r3, [r2]
60		add	r2, r2, r3
61		add	r3, r2, r1
62		mov	r1, #0
63		strb	r1, [r3]
641:		and	r1, r0, #15
65		mov	r0, r0, lsr #4
66		cmp	r1, #10
67		addlt	r1, r1, #'0'
68		addge	r1, r1, #'a' - 10
69		strb	r1, [r3, #-1]!
70		teq	r3, r2
71		bne	1b
72		mov	r0, r2
73		b	printascii
74ENDPROC(printhex2)
75
76		.pushsection .bss
77hexbuf_addr:	.space 16
78		.popsection
79		.align
80hexbuf_rel:	.long	hexbuf_addr - .
81
82		.ltorg
83
84#ifndef CONFIG_DEBUG_SEMIHOSTING
85
86ENTRY(printascii)
87		addruart_current r3, r1, r2
881:		teq	r0, #0
89		ldrneb	r1, [r0], #1
90		teqne	r1, #0
91		reteq	lr
922:		teq     r1, #'\n'
93		bne	3f
94		mov	r1, #'\r'
95		waituart r2, r3
96		senduart r1, r3
97		busyuart r2, r3
98		mov	r1, #'\n'
993:		waituart r2, r3
100		senduart r1, r3
101		busyuart r2, r3
102		b	1b
103ENDPROC(printascii)
104
105ENTRY(printch)
106		addruart_current r3, r1, r2
107		mov	r1, r0
108		mov	r0, #0
109		b	2b
110ENDPROC(printch)
111
112#ifdef CONFIG_MMU
113ENTRY(debug_ll_addr)
114		addruart r2, r3, ip
115		str	r2, [r0]
116		str	r3, [r1]
117		ret	lr
118ENDPROC(debug_ll_addr)
119#endif
120
121#else
122
123ENTRY(printascii)
124		mov	r1, r0
125		mov	r0, #0x04		@ SYS_WRITE0
126	ARM(	svc	#0x123456	)
127#ifdef CONFIG_CPU_V7M
128	THUMB(	bkpt	#0xab		)
129#else
130	THUMB(	svc	#0xab		)
131#endif
132		ret	lr
133ENDPROC(printascii)
134
135ENTRY(printch)
136		adr	r1, hexbuf_rel
137		ldr	r2, [r1]
138		add	r1, r1, r2
139		strb	r0, [r1]
140		mov	r0, #0x03		@ SYS_WRITEC
141	ARM(	svc	#0x123456	)
142#ifdef CONFIG_CPU_V7M
143	THUMB(	bkpt	#0xab		)
144#else
145	THUMB(	svc	#0xab		)
146#endif
147		ret	lr
148ENDPROC(printch)
149
150ENTRY(debug_ll_addr)
151		mov	r2, #0
152		str	r2, [r0]
153		str	r2, [r1]
154		ret	lr
155ENDPROC(debug_ll_addr)
156
157#endif
158