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