1/* $NetBSD: debug.s,v 1.11 2008/04/28 20:23:10 martin Exp $ */
2
3/*-
4 * Copyright (c) 1999, 2001 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33__KERNEL_RCSID(6, "$NetBSD: debug.s,v 1.11 2008/04/28 20:23:10 martin Exp $")
34
35#include "opt_multiprocessor.h"
36#include "opt_kgdb.h"
37
38/*
39 * Debugger glue.
40 */
41
42	.text
43inc6:	.stabs	__FILE__,132,0,0,inc6; .loc	1 __LINE__
44
45/*
46 * Debugger stack.
47 */
48#define	DEBUG_STACK_SIZE	8192
49BSS(debug_stack_bottom, DEBUG_STACK_SIZE)
50
51#define debug_stack_top		(debug_stack_bottom + DEBUG_STACK_SIZE)
52
53/*
54 * alpha_debug:
55 *
56 *	Single debugger entry point, handling the housekeeping
57 *	chores we need to deal with.
58 *
59 *	Arguments are:
60 *
61 *		a0	a0 from trap
62 *		a1	a1 from trap
63 *		a2	a2 from trap
64 *		a3	kernel trap entry point
65 *		a4	frame pointer
66 */
67NESTED_NOPROFILE(alpha_debug, 5, 32, ra, IM_RA|IM_S0, 0)
68	br	pv, 1f
691:	LDGP(pv)
70	lda	t0, FRAME_SIZE*8(a4)	/* what would sp have been? */
71	stq	t0, FRAME_SP*8(a4)	/* belatedly save sp for ddb view */
72	lda	sp, -32(sp)		/* set up stack frame */
73	stq	ra, (32-8)(sp)		/* save ra */
74	stq	s0, (32-16)(sp)		/* save s0 */
75
76	/* Remember our current stack pointer. */
77	mov	sp, s0
78
79#if defined(MULTIPROCESSOR)
80	/* Pause all other CPUs. */
81	ldiq	a0, 1
82	CALL(cpu_pause_resume_all)
83#endif
84
85	/*
86	 * Switch to the debug stack if we're not on it already.
87	 */
88	lda	t0, debug_stack_bottom
89	cmpule	sp, t0, t1		/* sp <= debug_stack_bottom */
90	bne	t1, 2f			/* yes, switch now */
91
92	lda	t0, debug_stack_top
93	cmpule	t0, sp, t1		/* debug_stack_top <= sp? */
94	bne	t1, 3f			/* yes, we're on the debug stack */
95
962:	lda	sp, debug_stack_top	/* sp <- debug_stack_top */
97
983:	/* Dispatch to the debugger - arguments are already in place. */
99#if defined(KGDB)
100	mov	a3, a0			/* a0 == entry (trap type) */
101	mov	a4, a1			/* a1 == frame pointer */
102	CALL(kgdb_trap)
103	br	9f
104#endif
105#if defined(DDB)
106	CALL(ddb_trap)
107	br	9f
108#endif
1099:	/* Debugger return value in v0; switch back to our previous stack. */
110	mov	s0, sp
111
112#if defined(MULTIPROCESSOR)
113	mov	v0, s0
114
115	/* Resume all other CPUs. */
116	mov	zero, a0
117	CALL(cpu_pause_resume_all)
118
119	mov	s0, v0
120#endif
121
122	ldq	ra, (32-8)(sp)		/* restore ra */
123	ldq	s0, (32-16)(sp)		/* restore s0 */
124	lda	sp, 32(sp)		/* pop stack frame */
125	RET
126	END(alpha_debug)
127