1 /* Remote target system call callback support.
2 Copyright 1997 Free Software Foundation, Inc.
3 Contributed by Cygnus Solutions.
5 This file is part of GDB.
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.
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.
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. */
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. */
26 /* There are various ways to handle system calls:
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.]
34 This method of system call handling is done when STATE_ENVIRONMENT
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
42 This method of system call handling is done when STATE_ENVIRONMENT
43 is ENVIRONMENT_OPERATING.
49 /* ??? The reason why we check for va_start here should be documented. */
53 #ifdef ANSI_PROTOTYPES
59 /* Needed for enum bfd_endian. */
62 /* Mapping of host/target values. */
63 /* ??? For debugging purposes, one might want to add a string of the
64 name of the symbol. */
71 #define MAX_CALLBACK_FDS 10
73 /* Forward decl for stat/fstat. */
76 typedef struct host_callback_struct host_callback
;
78 struct host_callback_struct
80 int (*close
) PARAMS ((host_callback
*,int));
81 int (*get_errno
) PARAMS ((host_callback
*));
82 int (*isatty
) PARAMS ((host_callback
*, int));
83 int (*lseek
) PARAMS ((host_callback
*, int, long , int));
84 int (*open
) PARAMS ((host_callback
*, const char*, int mode
));
85 int (*read
) PARAMS ((host_callback
*,int, char *, int));
86 int (*read_stdin
) PARAMS (( host_callback
*, char *, int));
87 int (*rename
) PARAMS ((host_callback
*, const char *, const char *));
88 int (*system
) PARAMS ((host_callback
*, const char *));
89 long (*time
) PARAMS ((host_callback
*, long *));
90 int (*unlink
) PARAMS ((host_callback
*, const char *));
91 int (*write
) PARAMS ((host_callback
*,int, const char *, int));
92 int (*write_stdout
) PARAMS ((host_callback
*, const char *, int));
93 void (*flush_stdout
) PARAMS ((host_callback
*));
94 int (*write_stderr
) PARAMS ((host_callback
*, const char *, int));
95 void (*flush_stderr
) PARAMS ((host_callback
*));
96 int (*stat
) PARAMS ((host_callback
*, const char *, struct stat
*));
97 int (*fstat
) PARAMS ((host_callback
*, int, struct stat
*));
98 int (*lstat
) PARAMS ((host_callback
*, const char *, struct stat
*));
99 int (*ftruncate
) PARAMS ((host_callback
*, int, long));
100 int (*truncate
) PARAMS ((host_callback
*, const char *, long));
101 int (*pipe
) PARAMS ((host_callback
*, int *));
103 /* Called by the framework when a read call has emptied a pipe buffer. */
104 void (*pipe_empty
) PARAMS ((host_callback
*, int read_fd
, int write_fd
));
106 /* Called by the framework when a write call makes a pipe buffer
108 void (*pipe_nonempty
) PARAMS ((host_callback
*, int read_fd
, int write_fd
));
110 /* When present, call to the client to give it the oportunity to
111 poll any io devices for a request to quit (indicated by a nonzero
113 int (*poll_quit
) PARAMS ((host_callback
*));
115 /* Used when the target has gone away, so we can close open
116 handles and free memory etc etc. */
117 int (*shutdown
) PARAMS ((host_callback
*));
118 int (*init
) PARAMS ((host_callback
*));
120 /* depreciated, use vprintf_filtered - Talk to the user on a console. */
121 void (*printf_filtered
) PARAMS ((host_callback
*, const char *, ...));
123 /* Talk to the user on a console. */
124 void (*vprintf_filtered
) PARAMS ((host_callback
*, const char *, va_list));
126 /* Same as vprintf_filtered but to stderr. */
127 void (*evprintf_filtered
) PARAMS ((host_callback
*, const char *, va_list));
129 /* Print an error message and "exit".
130 In the case of gdb "exiting" means doing a longjmp back to the main
132 void (*error
) PARAMS ((host_callback
*, const char *, ...));
134 int last_errno
; /* host format */
136 int fdmap
[MAX_CALLBACK_FDS
];
137 /* fd_buddy is used to contruct circular lists of target fds that point to
138 the same host fd. A uniquely mapped fd points to itself; for a closed
139 one, fd_buddy has the value -1. The host file descriptors for stdin /
140 stdout / stderr are never closed by the simulators, so they are put
141 in a special fd_buddy circular list which also has MAX_CALLBACK_FDS
143 /* ??? We don't have a callback entry for dup, although it is trival to
145 short fd_buddy
[MAX_CALLBACK_FDS
+1];
147 /* 0 = none, >0 = reader (index of writer),
148 <0 = writer (negative index of reader).
149 If abs (ispipe[N]) == N, then N is an end of a pipe whose other
151 short ispipe
[MAX_CALLBACK_FDS
];
153 /* A writer stores the buffer at its index. Consecutive writes
154 realloc the buffer and add to the size. The reader indicates the
155 read part in its .size, until it has consumed it all, at which
156 point it deallocates the buffer and zeroes out both sizes. */
157 struct pipe_write_buffer
161 } pipe_buffer
[MAX_CALLBACK_FDS
];
163 /* System call numbers. */
164 CB_TARGET_DEFS_MAP
*syscall_map
;
166 CB_TARGET_DEFS_MAP
*errno_map
;
167 /* Flags to the open system call. */
168 CB_TARGET_DEFS_MAP
*open_map
;
169 /* Signal numbers. */
170 CB_TARGET_DEFS_MAP
*signal_map
;
171 /* Layout of `stat' struct.
172 The format is a series of "name,length" pairs separated by colons.
173 Empty space is indicated with a `name' of "space".
174 All padding must be explicitly mentioned.
175 Lengths are in bytes. If this needs to be extended to bits,
177 Example: "st_dev,4:st_ino,4:st_mode,4:..." */
178 const char *stat_map
;
180 enum bfd_endian target_endian
;
182 /* Size of an "int" on the target (for syscalls whose ABI uses "int").
183 This must include padding, and only padding-at-higher-address is
184 supported. For example, a 64-bit target with 32-bit int:s which
185 are padded to 64 bits when in an array, should supposedly set this
186 to 8. The default is 4 which matches ILP32 targets and 64-bit
187 targets with 32-bit ints and no padding. */
188 int target_sizeof_int
;
190 /* Marker for those wanting to do sanity checks.
191 This should remain the last member of this struct to help catch
192 miscompilation errors. */
193 #define HOST_CALLBACK_MAGIC 4705 /* teds constant */
197 extern host_callback default_callback
;
199 /* Canonical versions of system call numbers.
200 It's not intended to willy-nilly throw every system call ever heard
201 of in here. Only include those that have an important use.
202 ??? One can certainly start a discussion over the ones that are currently
203 here, but that will always be true. */
205 /* These are used by the ANSI C support of libc. */
206 #define CB_SYS_exit 1
207 #define CB_SYS_open 2
208 #define CB_SYS_close 3
209 #define CB_SYS_read 4
210 #define CB_SYS_write 5
211 #define CB_SYS_lseek 6
212 #define CB_SYS_unlink 7
213 #define CB_SYS_getpid 8
214 #define CB_SYS_kill 9
215 #define CB_SYS_fstat 10
216 /*#define CB_SYS_sbrk 11 - not currently a system call, but reserved. */
219 #define CB_SYS_argvlen 12
220 #define CB_SYS_argv 13
222 /* These are extras added for one reason or another. */
223 #define CB_SYS_chdir 14
224 #define CB_SYS_stat 15
225 #define CB_SYS_chmod 16
226 #define CB_SYS_utime 17
227 #define CB_SYS_time 18
229 /* More standard syscalls. */
230 #define CB_SYS_lstat 19
231 #define CB_SYS_rename 20
232 #define CB_SYS_truncate 21
233 #define CB_SYS_ftruncate 22
234 #define CB_SYS_pipe 23
236 /* Struct use to pass and return information necessary to perform a
238 /* FIXME: Need to consider target word size. */
240 typedef struct cb_syscall
{
241 /* The target's value of what system call to perform. */
243 /* The arguments to the syscall. */
244 long arg1
, arg2
, arg3
, arg4
;
248 /* Some system calls have two results. */
250 /* The target's errno value, or 0 if success.
251 This is converted to the target's value with host_to_target_errno. */
254 /* Working space to be used by memory read/write callbacks. */
259 /* Callbacks for reading/writing memory (e.g. for read/write syscalls).
260 ??? long or unsigned long might be better to use for the `count'
261 argument here. We mimic sim_{read,write} for now. Be careful to
262 test any changes with -Wall -Werror, mixed signed comparisons
264 int (*read_mem
) PARAMS ((host_callback
* /*cb*/, struct cb_syscall
* /*sc*/,
265 unsigned long /*taddr*/, char * /*buf*/,
267 int (*write_mem
) PARAMS ((host_callback
* /*cb*/, struct cb_syscall
* /*sc*/,
268 unsigned long /*taddr*/, const char * /*buf*/,
271 /* For sanity checking, should be last entry. */
275 /* Magic number sanity checker. */
276 #define CB_SYSCALL_MAGIC 0x12344321
278 /* Macro to initialize CB_SYSCALL. Called first, before filling in
280 #define CB_SYSCALL_INIT(sc) \
282 memset ((sc), 0, sizeof (*(sc))); \
283 (sc)->magic = CB_SYSCALL_MAGIC; \
286 /* Return codes for various interface routines. */
292 /* either file not found or no read access */
297 /* Read in target values for system call numbers, errno values, signals. */
298 CB_RC cb_read_target_syscall_maps
PARAMS ((host_callback
*, const char *));
300 /* Translate target to host syscall function numbers. */
301 int cb_target_to_host_syscall
PARAMS ((host_callback
*, int));
303 /* Translate host to target errno value. */
304 int cb_host_to_target_errno
PARAMS ((host_callback
*, int));
306 /* Translate target to host open flags. */
307 int cb_target_to_host_open
PARAMS ((host_callback
*, int));
309 /* Translate target signal number to host. */
310 int cb_target_to_host_signal
PARAMS ((host_callback
*, int));
312 /* Translate host signal number to target. */
313 int cb_host_to_target_signal
PARAMS ((host_callback
*, int));
315 /* Translate host stat struct to target.
316 If stat struct ptr is NULL, just compute target stat struct size.
317 Result is size of target stat struct or 0 if error. */
318 int cb_host_to_target_stat
PARAMS ((host_callback
*, const struct stat
*, PTR
));
320 /* Translate a value to target endian. */
321 void cb_store_target_endian
PARAMS ((host_callback
*, char *, int, long));
323 /* Perform a system call. */
324 CB_RC cb_syscall
PARAMS ((host_callback
*, CB_SYSCALL
*));