1/* user.h: FR-V core file format stuff
2 *
3 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#ifndef _ASM_USER_H
12#define _ASM_USER_H
13
14#include <asm/page.h>
15#include <asm/registers.h>
16
17/* Core file format: The core file is written in such a way that gdb
18 * can understand it and provide useful information to the user (under
19 * linux we use the 'trad-core' bfd).  There are quite a number of
20 * obstacles to being able to view the contents of the floating point
21 * registers, and until these are solved you will not be able to view
22 * the contents of them.  Actually, you can read in the core file and
23 * look at the contents of the user struct to find out what the
24 * floating point registers contain.
25 *
26 * The actual file contents are as follows:
27 * UPAGE:
28 *   1 page consisting of a user struct that tells gdb what is present
29 *   in the file.  Directly after this is a copy of the task_struct,
30 *   which is currently not used by gdb, but it may come in useful at
31 *   some point.  All of the registers are stored as part of the
32 *   upage.  The upage should always be only one page.
33 *
34 * DATA:
35 *   The data area is stored.  We use current->end_text to
36 *   current->brk to pick up all of the user variables, plus any
37 *   memory that may have been malloced.  No attempt is made to
38 *   determine if a page is demand-zero or if a page is totally
39 *   unused, we just cover the entire range.  All of the addresses are
40 *   rounded in such a way that an integral number of pages is
41 *   written.
42 *
43 * STACK:
44 *   We need the stack information in order to get a meaningful
45 *   backtrace.  We need to write the data from (esp) to
46 *   current->start_stack, so we round each of these off in order to
47 *   be able to write an integer number of pages.  The minimum core
48 *   file size is 3 pages, or 12288 bytes.
49 */
50
51/* When the kernel dumps core, it starts by dumping the user struct -
52 * this will be used by gdb to figure out where the data and stack segments
53 *  are within the file, and what virtual addresses to use.
54 */
55struct user {
56	/* We start with the registers, to mimic the way that "memory" is returned
57	 * from the ptrace(3,...) function.  */
58	struct user_context	regs;
59
60	/* The rest of this junk is to help gdb figure out what goes where */
61	unsigned long		u_tsize;	/* Text segment size (pages). */
62	unsigned long		u_dsize;	/* Data segment size (pages). */
63	unsigned long		u_ssize;	/* Stack segment size (pages). */
64	unsigned long		start_code;     /* Starting virtual address of text. */
65	unsigned long		start_stack;	/* Starting virtual address of stack area.
66						 * This is actually the bottom of the stack,
67						 * the top of the stack is always found in the
68						 * esp register.  */
69	long int		signal;		/* Signal that caused the core dump. */
70
71	unsigned long		magic;		/* To uniquely identify a core file */
72	char			u_comm[32];	/* User command that was responsible */
73};
74
75#define NBPG			PAGE_SIZE
76#define UPAGES			1
77#define HOST_TEXT_START_ADDR	(u.start_code)
78#define HOST_STACK_END_ADDR	(u.start_stack + u.u_ssize * NBPG)
79
80#endif
81