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