include/callback.h

   1 /* Remote target system call callback support.
   2    Copyright 1997 Free Software Foundation, Inc.
   3    Contributed by Cygnus Solutions.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 /* This interface isn't intended to be specific to any particular kind
  22    of remote (hardware, simulator, whatever).  As such, support for it
  23    (e.g. sim/common/callback.c) should *not* live in the simulator source
  24    tree, nor should it live in the gdb source tree.  */
  25
  26 /* There are various ways to handle system calls:
  27
  28    1) Have a simulator intercept the appropriate trap instruction and
  29    directly perform the system call on behalf of the target program.
  30    This is the typical way of handling system calls for embedded targets.
  31    [Handling system calls for embedded targets isn't that much of an
  32    oxymoron as running compiler testsuites make use of the capability.]
  33
  34    This method of system call handling is done when STATE_ENVIRONMENT
  35    is ENVIRONMENT_USER.
  36
  37    2) Have a simulator emulate the hardware as much as possible.
  38    If the program running on the real hardware communicates with some sort
  39    of target manager, one would want to be able to run this program on the
  40    simulator as well.
  41
  42    This method of system call handling is done when STATE_ENVIRONMENT
  43    is ENVIRONMENT_OPERATING.
  44 */
  45
  46 #ifndef CALLBACK_H
  47 #define CALLBACK_H
  48
  49 /* ??? The reason why we check for va_start here should be documented.  */
  50
  51 #ifndef va_start
  52 #include <ansidecl.h>
  53 #ifdef ANSI_PROTOTYPES
  54 #include <stdarg.h>
  55 #else
  56 #include <varargs.h>
  57 #endif
  58 #endif
  59 \f
  60 /* Mapping of host/target values.  */
  61 /* ??? For debugging purposes, one might want to add a string of the
  62    name of the symbol.  */
  63
  64 typedef struct {
  65   int host_val;
  66   int target_val;
  67 } CB_TARGET_DEFS_MAP;
  68
  69 #define MAX_CALLBACK_FDS 10
  70
  71 typedef struct host_callback_struct host_callback;
  72
  73 struct host_callback_struct
  74 {
  75   int (*close) PARAMS ((host_callback *,int));
  76   int (*get_errno) PARAMS ((host_callback *));
  77   int (*isatty) PARAMS ((host_callback *, int));
  78   int (*lseek) PARAMS ((host_callback *, int, long , int));
  79   int (*open) PARAMS ((host_callback *, const char*, int mode));
  80   int (*read) PARAMS ((host_callback *,int,  char *, int));
  81   int (*read_stdin) PARAMS (( host_callback *, char *, int));
  82   int (*rename) PARAMS ((host_callback *, const char *, const char *));
  83   int (*system) PARAMS ((host_callback *, const char *));
  84   long (*time) PARAMS ((host_callback *, long *));
  85   int (*unlink) PARAMS ((host_callback *, const char *));
  86   int (*write) PARAMS ((host_callback *,int, const char *, int));
  87   int (*write_stdout) PARAMS ((host_callback *, const char *, int));
  88   void (*flush_stdout) PARAMS ((host_callback *));
  89   int (*write_stderr) PARAMS ((host_callback *, const char *, int));
  90   void (*flush_stderr) PARAMS ((host_callback *));
  91   /* PTR is not `struct stat' because the target's value is stored.  */
  92   int (*stat) PARAMS ((host_callback *, const char *, PTR));
  93   int (*fstat) PARAMS ((host_callback *, int, PTR));
  94
  95   /* When present, call to the client to give it the oportunity to
  96      poll any io devices for a request to quit (indicated by a nonzero
  97      return value). */
  98   int (*poll_quit) PARAMS ((host_callback *));
  99
 100   /* Used when the target has gone away, so we can close open
 101      handles and free memory etc etc.  */
 102   int (*shutdown) PARAMS ((host_callback *));
 103   int (*init)     PARAMS ((host_callback *));
 104
 105   /* depreciated, use vprintf_filtered - Talk to the user on a console.  */
 106   void (*printf_filtered) PARAMS ((host_callback *, const char *, ...));
 107
 108   /* Talk to the user on a console.  */
 109   void (*vprintf_filtered) PARAMS ((host_callback *, const char *, va_list));
 110
 111   /* Same as vprintf_filtered but to stderr.  */
 112   void (*evprintf_filtered) PARAMS ((host_callback *, const char *, va_list));
 113
 114   /* Print an error message and "exit".
 115      In the case of gdb "exiting" means doing a longjmp back to the main
 116      command loop.  */
 117   void (*error) PARAMS ((host_callback *, const char *, ...));
 118
 119   int last_errno;               /* host format */
 120
 121   int fdmap[MAX_CALLBACK_FDS];
 122   char fdopen[MAX_CALLBACK_FDS];
 123   char alwaysopen[MAX_CALLBACK_FDS];
 124
 125   /* System call numbers.  */
 126   CB_TARGET_DEFS_MAP *syscall_map;
 127   /* Errno values.  */
 128   CB_TARGET_DEFS_MAP *errno_map;
 129   /* Flags to the open system call.  */
 130   CB_TARGET_DEFS_MAP *open_map;
 131   /* Signal numbers.  */
 132   CB_TARGET_DEFS_MAP *signal_map;
 133   /* Layout of `stat' struct.
 134      The format is a series of "name,length" pairs separated by colons.
 135      Empty space is indicated with a `name' of "space".
 136      All padding must be explicitly mentioned.
 137      Lengths are in bytes.  If this needs to be extended to bits,
 138      use "name.bits".
 139      Example: "st_dev,4:st_ino,4:st_mode,4:..."  */
 140   const char *stat_map;
 141
 142   /* Marker for those wanting to do sanity checks.
 143      This should remain the last member of this struct to help catch
 144      miscompilation errors. */
 145 #define HOST_CALLBACK_MAGIC 4705 /* teds constant */
 146   int magic;
 147 };
 148
 149 extern host_callback default_callback;
 150 \f
 151 /* Canonical versions of system call numbers.
 152    It's not intended to willy-nilly throw every system call ever heard
 153    of in here.  Only include those that have an important use.  */
 154
 155 #define CB_SYS_exit     1
 156 #define CB_SYS_open     2
 157 #define CB_SYS_close    3
 158 #define CB_SYS_read     4
 159 #define CB_SYS_write    5
 160 #define CB_SYS_lseek    6
 161 #define CB_SYS_unlink   7
 162 #define CB_SYS_getpid   8
 163 #define CB_SYS_kill     9
 164 #define CB_SYS_fstat       10
 165 /*#define CB_SYS_sbrk   11 - not currently a system call, but reserved.  */
 166
 167 /* ARGV support.  */
 168 #define CB_SYS_argvlen  12
 169 #define CB_SYS_argv     13
 170
 171 /* These are extras added for one reason or another.  */
 172 #define CB_SYS_chdir    20
 173 #define CB_SYS_stat     21
 174 #define CB_SYS_chmod    22
 175 #define CB_SYS_utime    23
 176 #define CB_SYS_time     24
 177 \f
 178 /* Struct use to pass and return information necessary to perform a
 179    system call.  */
 180 /* FIXME: Need to consider target word size.  */
 181
 182 typedef struct cb_syscall {
 183   /* The target's value of what system call to perform.  */
 184   int func;
 185   /* The arguments to the syscall.  */
 186   long arg1, arg2, arg3, arg4;
 187
 188   /* The result.  */
 189   long result;
 190   /* Some system calls have two results.  */
 191   long result2;
 192   /* The target's errno value, or 0 if success.
 193      This is converted to the target's value with host_to_target_errno.  */
 194   int errcode;
 195
 196   /* Working space to be used by memory read/write callbacks.  */
 197   long x1,x2;
 198
 199   /* Callbacks for reading/writing memory (e.g. for read/write syscalls).  */
 200   unsigned long (*read_mem) PARAMS ((host_callback *, struct cb_syscall *, unsigned long taddr, char *buf, unsigned long bytes));
 201   unsigned long (*write_mem) PARAMS ((host_callback *, struct cb_syscall *, unsigned long taddr, const char *buf, unsigned long bytes));
 202 } CB_SYSCALL;
 203 \f
 204 /* Return codes for various interface routines.  */
 205
 206 typedef enum {
 207   CB_RC_OK = 0,
 208   /* generic error */
 209   CB_RC_ERR,
 210   /* either file not found or no read access */
 211   CB_RC_ACCESS,
 212   CB_RC_NO_MEM
 213 } CB_RC;
 214
 215 /* Read in target values for system call numbers, errno values, signals.  */
 216 CB_RC cb_read_target_syscall_maps PARAMS ((host_callback *, const char *));
 217
 218 /* Translate target to host syscall function numbers.  */
 219 int cb_target_to_host_syscall PARAMS ((host_callback *, int));
 220
 221 /* Translate host to target errno value.  */
 222 int cb_host_to_target_errno PARAMS ((host_callback *, int));
 223
 224 /* Translate target to host open flags.  */
 225 int cb_target_to_host_open PARAMS ((host_callback *, int));
 226
 227 /* Translate target signal number to host.  */
 228 int cb_target_to_host_signal PARAMS ((host_callback *, int));
 229
 230 /* Translate host signal number to target.  */
 231 int cb_host_to_target_signal PARAMS ((host_callback *, int));
 232
 233 /* Translate host stat struct to target.  */
 234 struct stat; /* forward decl */
 235 int cb_host_to_target_stat PARAMS ((host_callback *, const struct stat *,
 236                                     PTR, int));
 237
 238 /* Perform a system call.  */
 239 CB_RC cb_syscall PARAMS ((host_callback *, CB_SYSCALL *));
 240
 241 #endif