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252b5132 | 1 | /* Remote target system call callback support. |
4b95cf5c | 2 | Copyright (C) 1997-2014 Free Software Foundation, Inc. |
252b5132 RH |
3 | Contributed by Cygnus Solutions. |
4 | ||
1d52ba21 | 5 | This file is part of GDB. |
252b5132 | 6 | |
1d52ba21 JB |
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 3 of the License, or | |
10 | (at your option) any later version. | |
252b5132 | 11 | |
1d52ba21 JB |
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. | |
252b5132 | 16 | |
1d52ba21 JB |
17 | You should have received a copy of the GNU General Public License |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
252b5132 RH |
19 | |
20 | /* This interface isn't intended to be specific to any particular kind | |
21 | of remote (hardware, simulator, whatever). As such, support for it | |
22 | (e.g. sim/common/callback.c) should *not* live in the simulator source | |
23 | tree, nor should it live in the gdb source tree. */ | |
24 | ||
25 | /* There are various ways to handle system calls: | |
26 | ||
27 | 1) Have a simulator intercept the appropriate trap instruction and | |
28 | directly perform the system call on behalf of the target program. | |
29 | This is the typical way of handling system calls for embedded targets. | |
30 | [Handling system calls for embedded targets isn't that much of an | |
31 | oxymoron as running compiler testsuites make use of the capability.] | |
32 | ||
33 | This method of system call handling is done when STATE_ENVIRONMENT | |
34 | is ENVIRONMENT_USER. | |
35 | ||
36 | 2) Have a simulator emulate the hardware as much as possible. | |
37 | If the program running on the real hardware communicates with some sort | |
38 | of target manager, one would want to be able to run this program on the | |
39 | simulator as well. | |
40 | ||
41 | This method of system call handling is done when STATE_ENVIRONMENT | |
42 | is ENVIRONMENT_OPERATING. | |
43 | */ | |
44 | ||
45 | #ifndef CALLBACK_H | |
46 | #define CALLBACK_H | |
47 | ||
48 | /* ??? The reason why we check for va_start here should be documented. */ | |
49 | ||
50 | #ifndef va_start | |
51 | #include <ansidecl.h> | |
252b5132 | 52 | #include <stdarg.h> |
252b5132 | 53 | #endif |
99b2a78e HPN |
54 | /* Needed for enum bfd_endian. */ |
55 | #include "bfd.h" | |
252b5132 RH |
56 | \f |
57 | /* Mapping of host/target values. */ | |
58 | /* ??? For debugging purposes, one might want to add a string of the | |
59 | name of the symbol. */ | |
60 | ||
61 | typedef struct { | |
62 | int host_val; | |
63 | int target_val; | |
64 | } CB_TARGET_DEFS_MAP; | |
65 | ||
66 | #define MAX_CALLBACK_FDS 10 | |
67 | ||
68 | /* Forward decl for stat/fstat. */ | |
69 | struct stat; | |
70 | ||
71 | typedef struct host_callback_struct host_callback; | |
72 | ||
73 | struct host_callback_struct | |
74 | { | |
6f2bc2ee MF |
75 | int (*close) (host_callback *,int); |
76 | int (*get_errno) (host_callback *); | |
77 | int (*isatty) (host_callback *, int); | |
78 | int (*lseek) (host_callback *, int, long , int); | |
79 | int (*open) (host_callback *, const char*, int mode); | |
80 | int (*read) (host_callback *,int, char *, int); | |
81 | int (*read_stdin) ( host_callback *, char *, int); | |
82 | int (*rename) (host_callback *, const char *, const char *); | |
83 | int (*system) (host_callback *, const char *); | |
84 | long (*time) (host_callback *, long *); | |
85 | int (*unlink) (host_callback *, const char *); | |
86 | int (*write) (host_callback *,int, const char *, int); | |
87 | int (*write_stdout) (host_callback *, const char *, int); | |
88 | void (*flush_stdout) (host_callback *); | |
89 | int (*write_stderr) (host_callback *, const char *, int); | |
90 | void (*flush_stderr) (host_callback *); | |
91 | int (*stat) (host_callback *, const char *, struct stat *); | |
92 | int (*fstat) (host_callback *, int, struct stat *); | |
93 | int (*lstat) (host_callback *, const char *, struct stat *); | |
94 | int (*ftruncate) (host_callback *, int, long); | |
95 | int (*truncate) (host_callback *, const char *, long); | |
96 | int (*pipe) (host_callback *, int *); | |
6a7e5cfe HPN |
97 | |
98 | /* Called by the framework when a read call has emptied a pipe buffer. */ | |
6f2bc2ee | 99 | void (*pipe_empty) (host_callback *, int read_fd, int write_fd); |
6a7e5cfe HPN |
100 | |
101 | /* Called by the framework when a write call makes a pipe buffer | |
102 | non-empty. */ | |
6f2bc2ee | 103 | void (*pipe_nonempty) (host_callback *, int read_fd, int write_fd); |
252b5132 RH |
104 | |
105 | /* When present, call to the client to give it the oportunity to | |
106 | poll any io devices for a request to quit (indicated by a nonzero | |
107 | return value). */ | |
6f2bc2ee | 108 | int (*poll_quit) (host_callback *); |
252b5132 RH |
109 | |
110 | /* Used when the target has gone away, so we can close open | |
111 | handles and free memory etc etc. */ | |
6f2bc2ee MF |
112 | int (*shutdown) (host_callback *); |
113 | int (*init) (host_callback *); | |
252b5132 RH |
114 | |
115 | /* depreciated, use vprintf_filtered - Talk to the user on a console. */ | |
6f2bc2ee | 116 | void (*printf_filtered) (host_callback *, const char *, ...); |
252b5132 RH |
117 | |
118 | /* Talk to the user on a console. */ | |
6f2bc2ee | 119 | void (*vprintf_filtered) (host_callback *, const char *, va_list); |
252b5132 RH |
120 | |
121 | /* Same as vprintf_filtered but to stderr. */ | |
6f2bc2ee | 122 | void (*evprintf_filtered) (host_callback *, const char *, va_list); |
252b5132 RH |
123 | |
124 | /* Print an error message and "exit". | |
125 | In the case of gdb "exiting" means doing a longjmp back to the main | |
126 | command loop. */ | |
6f2bc2ee | 127 | void (*error) (host_callback *, const char *, ...) |
ec383c73 HPN |
128 | #ifdef __GNUC__ |
129 | __attribute__ ((__noreturn__)) | |
130 | #endif | |
131 | ; | |
252b5132 RH |
132 | |
133 | int last_errno; /* host format */ | |
134 | ||
135 | int fdmap[MAX_CALLBACK_FDS]; | |
594ee3a7 JR |
136 | /* fd_buddy is used to contruct circular lists of target fds that point to |
137 | the same host fd. A uniquely mapped fd points to itself; for a closed | |
138 | one, fd_buddy has the value -1. The host file descriptors for stdin / | |
139 | stdout / stderr are never closed by the simulators, so they are put | |
140 | in a special fd_buddy circular list which also has MAX_CALLBACK_FDS | |
141 | as a member. */ | |
142 | /* ??? We don't have a callback entry for dup, although it is trival to | |
143 | implement now. */ | |
144 | short fd_buddy[MAX_CALLBACK_FDS+1]; | |
252b5132 | 145 | |
6a7e5cfe HPN |
146 | /* 0 = none, >0 = reader (index of writer), |
147 | <0 = writer (negative index of reader). | |
148 | If abs (ispipe[N]) == N, then N is an end of a pipe whose other | |
149 | end is closed. */ | |
150 | short ispipe[MAX_CALLBACK_FDS]; | |
151 | ||
152 | /* A writer stores the buffer at its index. Consecutive writes | |
153 | realloc the buffer and add to the size. The reader indicates the | |
154 | read part in its .size, until it has consumed it all, at which | |
155 | point it deallocates the buffer and zeroes out both sizes. */ | |
156 | struct pipe_write_buffer | |
157 | { | |
158 | int size; | |
159 | char *buffer; | |
160 | } pipe_buffer[MAX_CALLBACK_FDS]; | |
161 | ||
252b5132 RH |
162 | /* System call numbers. */ |
163 | CB_TARGET_DEFS_MAP *syscall_map; | |
164 | /* Errno values. */ | |
165 | CB_TARGET_DEFS_MAP *errno_map; | |
166 | /* Flags to the open system call. */ | |
167 | CB_TARGET_DEFS_MAP *open_map; | |
168 | /* Signal numbers. */ | |
169 | CB_TARGET_DEFS_MAP *signal_map; | |
170 | /* Layout of `stat' struct. | |
171 | The format is a series of "name,length" pairs separated by colons. | |
172 | Empty space is indicated with a `name' of "space". | |
173 | All padding must be explicitly mentioned. | |
174 | Lengths are in bytes. If this needs to be extended to bits, | |
175 | use "name.bits". | |
176 | Example: "st_dev,4:st_ino,4:st_mode,4:..." */ | |
177 | const char *stat_map; | |
178 | ||
99b2a78e HPN |
179 | enum bfd_endian target_endian; |
180 | ||
6a7e5cfe HPN |
181 | /* Size of an "int" on the target (for syscalls whose ABI uses "int"). |
182 | This must include padding, and only padding-at-higher-address is | |
183 | supported. For example, a 64-bit target with 32-bit int:s which | |
184 | are padded to 64 bits when in an array, should supposedly set this | |
185 | to 8. The default is 4 which matches ILP32 targets and 64-bit | |
186 | targets with 32-bit ints and no padding. */ | |
187 | int target_sizeof_int; | |
188 | ||
252b5132 RH |
189 | /* Marker for those wanting to do sanity checks. |
190 | This should remain the last member of this struct to help catch | |
191 | miscompilation errors. */ | |
192 | #define HOST_CALLBACK_MAGIC 4705 /* teds constant */ | |
193 | int magic; | |
194 | }; | |
195 | ||
196 | extern host_callback default_callback; | |
197 | \f | |
198 | /* Canonical versions of system call numbers. | |
199 | It's not intended to willy-nilly throw every system call ever heard | |
200 | of in here. Only include those that have an important use. | |
201 | ??? One can certainly start a discussion over the ones that are currently | |
202 | here, but that will always be true. */ | |
203 | ||
204 | /* These are used by the ANSI C support of libc. */ | |
205 | #define CB_SYS_exit 1 | |
206 | #define CB_SYS_open 2 | |
207 | #define CB_SYS_close 3 | |
208 | #define CB_SYS_read 4 | |
209 | #define CB_SYS_write 5 | |
210 | #define CB_SYS_lseek 6 | |
211 | #define CB_SYS_unlink 7 | |
212 | #define CB_SYS_getpid 8 | |
213 | #define CB_SYS_kill 9 | |
214 | #define CB_SYS_fstat 10 | |
215 | /*#define CB_SYS_sbrk 11 - not currently a system call, but reserved. */ | |
216 | ||
217 | /* ARGV support. */ | |
218 | #define CB_SYS_argvlen 12 | |
219 | #define CB_SYS_argv 13 | |
220 | ||
221 | /* These are extras added for one reason or another. */ | |
222 | #define CB_SYS_chdir 14 | |
223 | #define CB_SYS_stat 15 | |
224 | #define CB_SYS_chmod 16 | |
225 | #define CB_SYS_utime 17 | |
226 | #define CB_SYS_time 18 | |
c4b36ce9 HPN |
227 | |
228 | /* More standard syscalls. */ | |
229 | #define CB_SYS_lstat 19 | |
d3ee64d1 | 230 | #define CB_SYS_rename 20 |
2adf959d HPN |
231 | #define CB_SYS_truncate 21 |
232 | #define CB_SYS_ftruncate 22 | |
6a7e5cfe | 233 | #define CB_SYS_pipe 23 |
81eb0a20 MF |
234 | |
235 | /* New ARGV support. */ | |
236 | #define CB_SYS_argc 24 | |
237 | #define CB_SYS_argnlen 25 | |
238 | #define CB_SYS_argn 26 | |
252b5132 RH |
239 | \f |
240 | /* Struct use to pass and return information necessary to perform a | |
241 | system call. */ | |
242 | /* FIXME: Need to consider target word size. */ | |
243 | ||
244 | typedef struct cb_syscall { | |
245 | /* The target's value of what system call to perform. */ | |
246 | int func; | |
247 | /* The arguments to the syscall. */ | |
248 | long arg1, arg2, arg3, arg4; | |
249 | ||
250 | /* The result. */ | |
251 | long result; | |
252 | /* Some system calls have two results. */ | |
253 | long result2; | |
254 | /* The target's errno value, or 0 if success. | |
255 | This is converted to the target's value with host_to_target_errno. */ | |
256 | int errcode; | |
257 | ||
258 | /* Working space to be used by memory read/write callbacks. */ | |
259 | PTR p1; | |
260 | PTR p2; | |
261 | long x1,x2; | |
262 | ||
263 | /* Callbacks for reading/writing memory (e.g. for read/write syscalls). | |
264 | ??? long or unsigned long might be better to use for the `count' | |
265 | argument here. We mimic sim_{read,write} for now. Be careful to | |
266 | test any changes with -Wall -Werror, mixed signed comparisons | |
267 | will get you. */ | |
6f2bc2ee MF |
268 | int (*read_mem) (host_callback * /*cb*/, struct cb_syscall * /*sc*/, |
269 | unsigned long /*taddr*/, char * /*buf*/, | |
270 | int /*bytes*/); | |
271 | int (*write_mem) (host_callback * /*cb*/, struct cb_syscall * /*sc*/, | |
272 | unsigned long /*taddr*/, const char * /*buf*/, | |
273 | int /*bytes*/); | |
252b5132 RH |
274 | |
275 | /* For sanity checking, should be last entry. */ | |
276 | int magic; | |
277 | } CB_SYSCALL; | |
278 | ||
279 | /* Magic number sanity checker. */ | |
280 | #define CB_SYSCALL_MAGIC 0x12344321 | |
281 | ||
282 | /* Macro to initialize CB_SYSCALL. Called first, before filling in | |
283 | any fields. */ | |
284 | #define CB_SYSCALL_INIT(sc) \ | |
285 | do { \ | |
286 | memset ((sc), 0, sizeof (*(sc))); \ | |
287 | (sc)->magic = CB_SYSCALL_MAGIC; \ | |
288 | } while (0) | |
289 | \f | |
290 | /* Return codes for various interface routines. */ | |
291 | ||
292 | typedef enum { | |
293 | CB_RC_OK = 0, | |
294 | /* generic error */ | |
295 | CB_RC_ERR, | |
296 | /* either file not found or no read access */ | |
297 | CB_RC_ACCESS, | |
298 | CB_RC_NO_MEM | |
299 | } CB_RC; | |
300 | ||
301 | /* Read in target values for system call numbers, errno values, signals. */ | |
6f2bc2ee | 302 | CB_RC cb_read_target_syscall_maps (host_callback *, const char *); |
252b5132 RH |
303 | |
304 | /* Translate target to host syscall function numbers. */ | |
6f2bc2ee | 305 | int cb_target_to_host_syscall (host_callback *, int); |
252b5132 RH |
306 | |
307 | /* Translate host to target errno value. */ | |
6f2bc2ee | 308 | int cb_host_to_target_errno (host_callback *, int); |
252b5132 RH |
309 | |
310 | /* Translate target to host open flags. */ | |
6f2bc2ee | 311 | int cb_target_to_host_open (host_callback *, int); |
252b5132 RH |
312 | |
313 | /* Translate target signal number to host. */ | |
6f2bc2ee | 314 | int cb_target_to_host_signal (host_callback *, int); |
252b5132 RH |
315 | |
316 | /* Translate host signal number to target. */ | |
2ea28649 | 317 | int cb_host_to_gdb_signal (host_callback *, int); |
252b5132 RH |
318 | |
319 | /* Translate host stat struct to target. | |
320 | If stat struct ptr is NULL, just compute target stat struct size. | |
321 | Result is size of target stat struct or 0 if error. */ | |
6f2bc2ee | 322 | int cb_host_to_target_stat (host_callback *, const struct stat *, PTR); |
252b5132 | 323 | |
99b2a78e | 324 | /* Translate a value to target endian. */ |
6f2bc2ee | 325 | void cb_store_target_endian (host_callback *, char *, int, long); |
99b2a78e | 326 | |
eb639c50 | 327 | /* Tests for special fds. */ |
6f2bc2ee MF |
328 | int cb_is_stdin (host_callback *, int); |
329 | int cb_is_stdout (host_callback *, int); | |
330 | int cb_is_stderr (host_callback *, int); | |
b981d709 | 331 | |
71712327 MF |
332 | /* Read a string out of the target. */ |
333 | int cb_get_string (host_callback *, CB_SYSCALL *, char *, int, unsigned long); | |
334 | ||
252b5132 | 335 | /* Perform a system call. */ |
6f2bc2ee | 336 | CB_RC cb_syscall (host_callback *, CB_SYSCALL *); |
252b5132 RH |
337 | |
338 | #endif |