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4f8d4a38 DD |
1 | /* syscalls.c --- implement system calls for the RX simulator. |
2 | ||
42a4f53d | 3 | Copyright (C) 2005-2019 Free Software Foundation, Inc. |
4f8d4a38 DD |
4 | Contributed by Red Hat, Inc. |
5 | ||
6 | This file is part of the GNU simulators. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 3 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | ||
8d794149 | 22 | #include "config.h" |
4f8d4a38 DD |
23 | #include <stdio.h> |
24 | #include <stdlib.h> | |
25 | #include <fcntl.h> | |
26 | #include <unistd.h> | |
27 | #include <sys/time.h> | |
28 | ||
29 | #include "gdb/callback.h" | |
30 | ||
31 | #include "cpu.h" | |
32 | #include "mem.h" | |
33 | #include "syscalls.h" | |
34 | ||
35 | #include "syscall.h" | |
36 | ||
37 | /* The current syscall callbacks we're using. */ | |
38 | static struct host_callback_struct *callbacks; | |
39 | ||
40 | void | |
41 | set_callbacks (struct host_callback_struct *cb) | |
42 | { | |
43 | callbacks = cb; | |
44 | } | |
45 | ||
d98bfeb0 KB |
46 | struct host_callback_struct * |
47 | get_callbacks (void) | |
48 | { | |
49 | return callbacks; | |
50 | } | |
51 | ||
4f8d4a38 DD |
52 | |
53 | /* Arguments 1..4 are in R1..R4, remainder on stack. | |
54 | ||
55 | Return value in R1..R4 as needed. | |
56 | structs bigger than 16 bytes: pointer pushed on stack last | |
57 | ||
58 | We only support arguments that fit in general registers. | |
59 | ||
60 | The system call number is in R5. We expect ssycalls to look like | |
61 | this in libgloss: | |
62 | ||
63 | _exit: | |
64 | mov #SYS_exit, r5 | |
65 | int #255 | |
66 | rts | |
67 | */ | |
68 | ||
69 | int argp, stackp; | |
70 | ||
71 | static int | |
72 | arg () | |
73 | { | |
74 | int rv = 0; | |
75 | argp++; | |
76 | ||
77 | if (argp < 4) | |
78 | return get_reg (argp); | |
79 | ||
80 | rv = mem_get_si (get_reg (sp) + stackp); | |
81 | stackp += 4; | |
82 | return rv; | |
83 | } | |
84 | ||
85 | static void | |
86 | read_target (char *buffer, int address, int count, int asciiz) | |
87 | { | |
88 | char byte; | |
89 | while (count > 0) | |
90 | { | |
91 | byte = mem_get_qi (address++); | |
92 | *buffer++ = byte; | |
93 | if (asciiz && (byte == 0)) | |
94 | return; | |
95 | count--; | |
96 | } | |
97 | } | |
98 | ||
99 | static void | |
100 | write_target (char *buffer, int address, int count, int asciiz) | |
101 | { | |
102 | char byte; | |
103 | while (count > 0) | |
104 | { | |
105 | byte = *buffer++; | |
106 | mem_put_qi (address++, byte); | |
107 | if (asciiz && (byte == 0)) | |
108 | return; | |
109 | count--; | |
110 | } | |
111 | } | |
112 | ||
113 | #define PTRSZ (A16 ? 2 : 3) | |
114 | ||
115 | static char *callnames[] = { | |
116 | "SYS_zero", | |
117 | "SYS_exit", | |
118 | "SYS_open", | |
119 | "SYS_close", | |
120 | "SYS_read", | |
121 | "SYS_write", | |
122 | "SYS_lseek", | |
123 | "SYS_unlink", | |
124 | "SYS_getpid", | |
125 | "SYS_kill", | |
126 | "SYS_fstat", | |
127 | "SYS_sbrk", | |
128 | "SYS_argvlen", | |
129 | "SYS_argv", | |
130 | "SYS_chdir", | |
131 | "SYS_stat", | |
132 | "SYS_chmod", | |
133 | "SYS_utime", | |
134 | "SYS_time", | |
135 | "SYS_gettimeofday", | |
136 | "SYS_times", | |
137 | "SYS_link" | |
138 | }; | |
139 | ||
140 | int | |
141 | rx_syscall (int id) | |
142 | { | |
143 | static char buf[256]; | |
144 | int rv; | |
145 | ||
146 | argp = 0; | |
147 | stackp = 4; | |
148 | if (trace) | |
149 | printf ("\033[31m/* SYSCALL(%d) = %s */\033[0m\n", id, id <= SYS_link ? callnames[id] : "unknown"); | |
150 | switch (id) | |
151 | { | |
152 | case SYS_exit: | |
153 | { | |
154 | int ec = arg (); | |
155 | if (verbose) | |
156 | printf ("[exit %d]\n", ec); | |
157 | return RX_MAKE_EXITED (ec); | |
158 | } | |
159 | break; | |
160 | ||
161 | case SYS_open: | |
162 | { | |
163 | int path = arg (); | |
164 | /* The open function is defined as taking a variable number of arguments | |
165 | because the third parameter to it is optional: | |
166 | open (const char * filename, int flags, ...); | |
167 | Hence the oflags and cflags arguments will be on the stack and we need | |
168 | to skip the (empty) argument registers r3 and r4. */ | |
169 | argp = 4; | |
170 | int oflags = arg (); | |
171 | int cflags = arg (); | |
172 | ||
173 | read_target (buf, path, 256, 1); | |
174 | if (trace) | |
175 | printf ("open(\"%s\",0x%x,%#o) = ", buf, oflags, cflags); | |
176 | ||
177 | if (callbacks) | |
178 | /* The callback vector ignores CFLAGS. */ | |
179 | rv = callbacks->open (callbacks, buf, oflags); | |
180 | else | |
181 | { | |
182 | int h_oflags = 0; | |
183 | ||
184 | if (oflags & 0x0001) | |
185 | h_oflags |= O_WRONLY; | |
186 | if (oflags & 0x0002) | |
187 | h_oflags |= O_RDWR; | |
188 | if (oflags & 0x0200) | |
189 | h_oflags |= O_CREAT; | |
190 | if (oflags & 0x0008) | |
191 | h_oflags |= O_APPEND; | |
192 | if (oflags & 0x0400) | |
193 | h_oflags |= O_TRUNC; | |
194 | rv = open (buf, h_oflags, cflags); | |
195 | } | |
196 | if (trace) | |
197 | printf ("%d\n", rv); | |
198 | put_reg (1, rv); | |
199 | } | |
200 | break; | |
201 | ||
202 | case SYS_close: | |
203 | { | |
204 | int fd = arg (); | |
205 | ||
206 | if (callbacks) | |
207 | rv = callbacks->close (callbacks, fd); | |
208 | else if (fd > 2) | |
209 | rv = close (fd); | |
210 | else | |
211 | rv = 0; | |
212 | if (trace) | |
213 | printf ("close(%d) = %d\n", fd, rv); | |
214 | put_reg (1, rv); | |
215 | } | |
216 | break; | |
217 | ||
218 | case SYS_read: | |
219 | { | |
220 | int fd = arg (); | |
221 | int addr = arg (); | |
222 | int count = arg (); | |
223 | ||
224 | if (count > sizeof (buf)) | |
225 | count = sizeof (buf); | |
226 | if (callbacks) | |
227 | rv = callbacks->read (callbacks, fd, buf, count); | |
228 | else | |
229 | rv = read (fd, buf, count); | |
230 | if (trace) | |
231 | printf ("read(%d,%d) = %d\n", fd, count, rv); | |
232 | if (rv > 0) | |
233 | write_target (buf, addr, rv, 0); | |
234 | put_reg (1, rv); | |
235 | } | |
236 | break; | |
237 | ||
238 | case SYS_write: | |
239 | { | |
240 | int fd = arg (); | |
241 | int addr = arg (); | |
242 | int count = arg (); | |
243 | ||
244 | if (count > sizeof (buf)) | |
245 | count = sizeof (buf); | |
246 | if (trace) | |
247 | printf ("write(%d,0x%x,%d)\n", fd, addr, count); | |
248 | read_target (buf, addr, count, 0); | |
249 | if (trace) | |
250 | fflush (stdout); | |
251 | if (callbacks) | |
252 | rv = callbacks->write (callbacks, fd, buf, count); | |
253 | else | |
254 | rv = write (fd, buf, count); | |
255 | if (trace) | |
256 | printf ("write(%d,%d) = %d\n", fd, count, rv); | |
257 | put_reg (1, rv); | |
258 | } | |
259 | break; | |
260 | ||
261 | case SYS_getpid: | |
262 | put_reg (1, 42); | |
263 | break; | |
264 | ||
265 | case SYS_gettimeofday: | |
266 | { | |
267 | int tvaddr = arg (); | |
268 | struct timeval tv; | |
269 | ||
270 | rv = gettimeofday (&tv, 0); | |
271 | if (trace) | |
272 | printf ("gettimeofday: %ld sec %ld usec to 0x%x\n", tv.tv_sec, | |
273 | tv.tv_usec, tvaddr); | |
274 | mem_put_si (tvaddr, tv.tv_sec); | |
275 | mem_put_si (tvaddr + 4, tv.tv_usec); | |
276 | put_reg (1, rv); | |
277 | } | |
278 | break; | |
279 | ||
280 | case SYS_kill: | |
281 | { | |
282 | int pid = arg (); | |
283 | int sig = arg (); | |
284 | if (pid == 42) | |
285 | { | |
286 | if (verbose) | |
287 | printf ("[signal %d]\n", sig); | |
288 | return RX_MAKE_STOPPED (sig); | |
289 | } | |
290 | } | |
291 | break; | |
292 | ||
293 | case 11: | |
294 | { | |
295 | int heaptop_arg = arg (); | |
296 | if (trace) | |
297 | printf ("sbrk: heap top set to %x\n", heaptop_arg); | |
298 | heaptop = heaptop_arg; | |
299 | if (heapbottom == 0) | |
300 | heapbottom = heaptop_arg; | |
301 | } | |
302 | break; | |
303 | ||
304 | case 255: | |
305 | { | |
306 | int addr = arg (); | |
307 | mem_put_si (addr, rx_cycles + mem_usage_cycles()); | |
308 | } | |
309 | break; | |
310 | ||
311 | } | |
312 | return RX_MAKE_STEPPED (); | |
313 | } |