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 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 /* Forward decl for stat/fstat. */ 72 struct stat; 73 74 typedef struct host_callback_struct host_callback; 75 76 struct host_callback_struct 77 { 78 int (*close) PARAMS ((host_callback *,int)); 79 int (*get_errno) PARAMS ((host_callback *)); 80 int (*isatty) PARAMS ((host_callback *, int)); 81 int (*lseek) PARAMS ((host_callback *, int, long , int)); 82 int (*open) PARAMS ((host_callback *, const char*, int mode)); 83 int (*read) PARAMS ((host_callback *,int, char *, int)); 84 int (*read_stdin) PARAMS (( host_callback *, char *, int)); 85 int (*rename) PARAMS ((host_callback *, const char *, const char *)); 86 int (*system) PARAMS ((host_callback *, const char *)); 87 long (*time) PARAMS ((host_callback *, long *)); 88 int (*unlink) PARAMS ((host_callback *, const char *)); 89 int (*write) PARAMS ((host_callback *,int, const char *, int)); 90 int (*write_stdout) PARAMS ((host_callback *, const char *, int)); 91 void (*flush_stdout) PARAMS ((host_callback *)); 92 int (*write_stderr) PARAMS ((host_callback *, const char *, int)); 93 void (*flush_stderr) PARAMS ((host_callback *)); 94 int (*stat) PARAMS ((host_callback *, const char *, struct stat *)); 95 int (*fstat) PARAMS ((host_callback *, int, struct stat *)); 96 int (*ftruncate) PARAMS ((host_callback *, int, long)); 97 int (*truncate) PARAMS ((host_callback *, const char *, long)); 98 99 /* When present, call to the client to give it the oportunity to 100 poll any io devices for a request to quit (indicated by a nonzero 101 return value). */ 102 int (*poll_quit) PARAMS ((host_callback *)); 103 104 /* Used when the target has gone away, so we can close open 105 handles and free memory etc etc. */ 106 int (*shutdown) PARAMS ((host_callback *)); 107 int (*init) PARAMS ((host_callback *)); 108 109 /* depreciated, use vprintf_filtered - Talk to the user on a console. */ 110 void (*printf_filtered) PARAMS ((host_callback *, const char *, ...)); 111 112 /* Talk to the user on a console. */ 113 void (*vprintf_filtered) PARAMS ((host_callback *, const char *, va_list)); 114 115 /* Same as vprintf_filtered but to stderr. */ 116 void (*evprintf_filtered) PARAMS ((host_callback *, const char *, va_list)); 117 118 /* Print an error message and "exit". 119 In the case of gdb "exiting" means doing a longjmp back to the main 120 command loop. */ 121 void (*error) PARAMS ((host_callback *, const char *, ...)); 122 123 int last_errno; /* host format */ 124 125 int fdmap[MAX_CALLBACK_FDS]; 126 char fdopen[MAX_CALLBACK_FDS]; 127 char alwaysopen[MAX_CALLBACK_FDS]; 128 129 /* System call numbers. */ 130 CB_TARGET_DEFS_MAP *syscall_map; 131 /* Errno values. */ 132 CB_TARGET_DEFS_MAP *errno_map; 133 /* Flags to the open system call. */ 134 CB_TARGET_DEFS_MAP *open_map; 135 /* Signal numbers. */ 136 CB_TARGET_DEFS_MAP *signal_map; 137 /* Layout of `stat' struct. 138 The format is a series of "name,length" pairs separated by colons. 139 Empty space is indicated with a `name' of "space". 140 All padding must be explicitly mentioned. 141 Lengths are in bytes. If this needs to be extended to bits, 142 use "name.bits". 143 Example: "st_dev,4:st_ino,4:st_mode,4:..." */ 144 const char *stat_map; 145 146 /* Marker for those wanting to do sanity checks. 147 This should remain the last member of this struct to help catch 148 miscompilation errors. */ 149 #define HOST_CALLBACK_MAGIC 4705 /* teds constant */ 150 int magic; 151 }; 152 153 extern host_callback default_callback; 154 155 /* Canonical versions of system call numbers. 156 It's not intended to willy-nilly throw every system call ever heard 157 of in here. Only include those that have an important use. 158 ??? One can certainly start a discussion over the ones that are currently 159 here, but that will always be true. */ 160 161 /* These are used by the ANSI C support of libc. */ 162 #define CB_SYS_exit 1 163 #define CB_SYS_open 2 164 #define CB_SYS_close 3 165 #define CB_SYS_read 4 166 #define CB_SYS_write 5 167 #define CB_SYS_lseek 6 168 #define CB_SYS_unlink 7 169 #define CB_SYS_getpid 8 170 #define CB_SYS_kill 9 171 #define CB_SYS_fstat 10 172 /*#define CB_SYS_sbrk 11 - not currently a system call, but reserved. */ 173 174 /* ARGV support. */ 175 #define CB_SYS_argvlen 12 176 #define CB_SYS_argv 13 177 178 /* These are extras added for one reason or another. */ 179 #define CB_SYS_chdir 14 180 #define CB_SYS_stat 15 181 #define CB_SYS_chmod 16 182 #define CB_SYS_utime 17 183 #define CB_SYS_time 18 184 185 /* Struct use to pass and return information necessary to perform a 186 system call. */ 187 /* FIXME: Need to consider target word size. */ 188 189 typedef struct cb_syscall { 190 /* The target's value of what system call to perform. */ 191 int func; 192 /* The arguments to the syscall. */ 193 long arg1, arg2, arg3, arg4; 194 195 /* The result. */ 196 long result; 197 /* Some system calls have two results. */ 198 long result2; 199 /* The target's errno value, or 0 if success. 200 This is converted to the target's value with host_to_target_errno. */ 201 int errcode; 202 203 /* Working space to be used by memory read/write callbacks. */ 204 PTR p1; 205 PTR p2; 206 long x1,x2; 207 208 /* Callbacks for reading/writing memory (e.g. for read/write syscalls). 209 ??? long or unsigned long might be better to use for the `count' 210 argument here. We mimic sim_{read,write} for now. Be careful to 211 test any changes with -Wall -Werror, mixed signed comparisons 212 will get you. */ 213 int (*read_mem) PARAMS ((host_callback * /*cb*/, struct cb_syscall * /*sc*/, 214 unsigned long /*taddr*/, char * /*buf*/, 215 int /*bytes*/)); 216 int (*write_mem) PARAMS ((host_callback * /*cb*/, struct cb_syscall * /*sc*/, 217 unsigned long /*taddr*/, const char * /*buf*/, 218 int /*bytes*/)); 219 220 /* For sanity checking, should be last entry. */ 221 int magic; 222 } CB_SYSCALL; 223 224 /* Magic number sanity checker. */ 225 #define CB_SYSCALL_MAGIC 0x12344321 226 227 /* Macro to initialize CB_SYSCALL. Called first, before filling in 228 any fields. */ 229 #define CB_SYSCALL_INIT(sc) \ 230 do { \ 231 memset ((sc), 0, sizeof (*(sc))); \ 232 (sc)->magic = CB_SYSCALL_MAGIC; \ 233 } while (0) 234 235 /* Return codes for various interface routines. */ 236 237 typedef enum { 238 CB_RC_OK = 0, 239 /* generic error */ 240 CB_RC_ERR, 241 /* either file not found or no read access */ 242 CB_RC_ACCESS, 243 CB_RC_NO_MEM 244 } CB_RC; 245 246 /* Read in target values for system call numbers, errno values, signals. */ 247 CB_RC cb_read_target_syscall_maps PARAMS ((host_callback *, const char *)); 248 249 /* Translate target to host syscall function numbers. */ 250 int cb_target_to_host_syscall PARAMS ((host_callback *, int)); 251 252 /* Translate host to target errno value. */ 253 int cb_host_to_target_errno PARAMS ((host_callback *, int)); 254 255 /* Translate target to host open flags. */ 256 int cb_target_to_host_open PARAMS ((host_callback *, int)); 257 258 /* Translate target signal number to host. */ 259 int cb_target_to_host_signal PARAMS ((host_callback *, int)); 260 261 /* Translate host signal number to target. */ 262 int cb_host_to_target_signal PARAMS ((host_callback *, int)); 263 264 /* Translate host stat struct to target. 265 If stat struct ptr is NULL, just compute target stat struct size. 266 Result is size of target stat struct or 0 if error. */ 267 int cb_host_to_target_stat PARAMS ((host_callback *, const struct stat *, PTR)); 268 269 /* Perform a system call. */ 270 CB_RC cb_syscall PARAMS ((host_callback *, CB_SYSCALL *)); 271 272 #endif 273