arch/frv/include/asm/user.h

   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  */
  55 struct 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