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4f8d4a38 DD |
1 | /* syscalls.c --- implement system calls for the RX simulator. |
2 | ||
dc3cf14f | 3 | Copyright (C) 2005, 2007, 2008, 2009, 2010 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 | ||
22 | #include <stdio.h> | |
23 | #include <stdlib.h> | |
24 | #include <fcntl.h> | |
25 | #include <unistd.h> | |
26 | #include <sys/time.h> | |
27 | ||
28 | #include "gdb/callback.h" | |
29 | ||
30 | #include "cpu.h" | |
31 | #include "mem.h" | |
32 | #include "syscalls.h" | |
33 | ||
34 | #include "syscall.h" | |
35 | ||
36 | /* The current syscall callbacks we're using. */ | |
37 | static struct host_callback_struct *callbacks; | |
38 | ||
39 | void | |
40 | set_callbacks (struct host_callback_struct *cb) | |
41 | { | |
42 | callbacks = cb; | |
43 | } | |
44 | ||
45 | ||
46 | /* Arguments 1..4 are in R1..R4, remainder on stack. | |
47 | ||
48 | Return value in R1..R4 as needed. | |
49 | structs bigger than 16 bytes: pointer pushed on stack last | |
50 | ||
51 | We only support arguments that fit in general registers. | |
52 | ||
53 | The system call number is in R5. We expect ssycalls to look like | |
54 | this in libgloss: | |
55 | ||
56 | _exit: | |
57 | mov #SYS_exit, r5 | |
58 | int #255 | |
59 | rts | |
60 | */ | |
61 | ||
62 | int argp, stackp; | |
63 | ||
64 | static int | |
65 | arg () | |
66 | { | |
67 | int rv = 0; | |
68 | argp++; | |
69 | ||
70 | if (argp < 4) | |
71 | return get_reg (argp); | |
72 | ||
73 | rv = mem_get_si (get_reg (sp) + stackp); | |
74 | stackp += 4; | |
75 | return rv; | |
76 | } | |
77 | ||
78 | static void | |
79 | read_target (char *buffer, int address, int count, int asciiz) | |
80 | { | |
81 | char byte; | |
82 | while (count > 0) | |
83 | { | |
84 | byte = mem_get_qi (address++); | |
85 | *buffer++ = byte; | |
86 | if (asciiz && (byte == 0)) | |
87 | return; | |
88 | count--; | |
89 | } | |
90 | } | |
91 | ||
92 | static void | |
93 | write_target (char *buffer, int address, int count, int asciiz) | |
94 | { | |
95 | char byte; | |
96 | while (count > 0) | |
97 | { | |
98 | byte = *buffer++; | |
99 | mem_put_qi (address++, byte); | |
100 | if (asciiz && (byte == 0)) | |
101 | return; | |
102 | count--; | |
103 | } | |
104 | } | |
105 | ||
106 | #define PTRSZ (A16 ? 2 : 3) | |
107 | ||
108 | static char *callnames[] = { | |
109 | "SYS_zero", | |
110 | "SYS_exit", | |
111 | "SYS_open", | |
112 | "SYS_close", | |
113 | "SYS_read", | |
114 | "SYS_write", | |
115 | "SYS_lseek", | |
116 | "SYS_unlink", | |
117 | "SYS_getpid", | |
118 | "SYS_kill", | |
119 | "SYS_fstat", | |
120 | "SYS_sbrk", | |
121 | "SYS_argvlen", | |
122 | "SYS_argv", | |
123 | "SYS_chdir", | |
124 | "SYS_stat", | |
125 | "SYS_chmod", | |
126 | "SYS_utime", | |
127 | "SYS_time", | |
128 | "SYS_gettimeofday", | |
129 | "SYS_times", | |
130 | "SYS_link" | |
131 | }; | |
132 | ||
133 | int | |
134 | rx_syscall (int id) | |
135 | { | |
136 | static char buf[256]; | |
137 | int rv; | |
138 | ||
139 | argp = 0; | |
140 | stackp = 4; | |
141 | if (trace) | |
142 | printf ("\033[31m/* SYSCALL(%d) = %s */\033[0m\n", id, id <= SYS_link ? callnames[id] : "unknown"); | |
143 | switch (id) | |
144 | { | |
145 | case SYS_exit: | |
146 | { | |
147 | int ec = arg (); | |
148 | if (verbose) | |
149 | printf ("[exit %d]\n", ec); | |
150 | return RX_MAKE_EXITED (ec); | |
151 | } | |
152 | break; | |
153 | ||
154 | case SYS_open: | |
155 | { | |
156 | int path = arg (); | |
157 | /* The open function is defined as taking a variable number of arguments | |
158 | because the third parameter to it is optional: | |
159 | open (const char * filename, int flags, ...); | |
160 | Hence the oflags and cflags arguments will be on the stack and we need | |
161 | to skip the (empty) argument registers r3 and r4. */ | |
162 | argp = 4; | |
163 | int oflags = arg (); | |
164 | int cflags = arg (); | |
165 | ||
166 | read_target (buf, path, 256, 1); | |
167 | if (trace) | |
168 | printf ("open(\"%s\",0x%x,%#o) = ", buf, oflags, cflags); | |
169 | ||
170 | if (callbacks) | |
171 | /* The callback vector ignores CFLAGS. */ | |
172 | rv = callbacks->open (callbacks, buf, oflags); | |
173 | else | |
174 | { | |
175 | int h_oflags = 0; | |
176 | ||
177 | if (oflags & 0x0001) | |
178 | h_oflags |= O_WRONLY; | |
179 | if (oflags & 0x0002) | |
180 | h_oflags |= O_RDWR; | |
181 | if (oflags & 0x0200) | |
182 | h_oflags |= O_CREAT; | |
183 | if (oflags & 0x0008) | |
184 | h_oflags |= O_APPEND; | |
185 | if (oflags & 0x0400) | |
186 | h_oflags |= O_TRUNC; | |
187 | rv = open (buf, h_oflags, cflags); | |
188 | } | |
189 | if (trace) | |
190 | printf ("%d\n", rv); | |
191 | put_reg (1, rv); | |
192 | } | |
193 | break; | |
194 | ||
195 | case SYS_close: | |
196 | { | |
197 | int fd = arg (); | |
198 | ||
199 | if (callbacks) | |
200 | rv = callbacks->close (callbacks, fd); | |
201 | else if (fd > 2) | |
202 | rv = close (fd); | |
203 | else | |
204 | rv = 0; | |
205 | if (trace) | |
206 | printf ("close(%d) = %d\n", fd, rv); | |
207 | put_reg (1, rv); | |
208 | } | |
209 | break; | |
210 | ||
211 | case SYS_read: | |
212 | { | |
213 | int fd = arg (); | |
214 | int addr = arg (); | |
215 | int count = arg (); | |
216 | ||
217 | if (count > sizeof (buf)) | |
218 | count = sizeof (buf); | |
219 | if (callbacks) | |
220 | rv = callbacks->read (callbacks, fd, buf, count); | |
221 | else | |
222 | rv = read (fd, buf, count); | |
223 | if (trace) | |
224 | printf ("read(%d,%d) = %d\n", fd, count, rv); | |
225 | if (rv > 0) | |
226 | write_target (buf, addr, rv, 0); | |
227 | put_reg (1, rv); | |
228 | } | |
229 | break; | |
230 | ||
231 | case SYS_write: | |
232 | { | |
233 | int fd = arg (); | |
234 | int addr = arg (); | |
235 | int count = arg (); | |
236 | ||
237 | if (count > sizeof (buf)) | |
238 | count = sizeof (buf); | |
239 | if (trace) | |
240 | printf ("write(%d,0x%x,%d)\n", fd, addr, count); | |
241 | read_target (buf, addr, count, 0); | |
242 | if (trace) | |
243 | fflush (stdout); | |
244 | if (callbacks) | |
245 | rv = callbacks->write (callbacks, fd, buf, count); | |
246 | else | |
247 | rv = write (fd, buf, count); | |
248 | if (trace) | |
249 | printf ("write(%d,%d) = %d\n", fd, count, rv); | |
250 | put_reg (1, rv); | |
251 | } | |
252 | break; | |
253 | ||
254 | case SYS_getpid: | |
255 | put_reg (1, 42); | |
256 | break; | |
257 | ||
258 | case SYS_gettimeofday: | |
259 | { | |
260 | int tvaddr = arg (); | |
261 | struct timeval tv; | |
262 | ||
263 | rv = gettimeofday (&tv, 0); | |
264 | if (trace) | |
265 | printf ("gettimeofday: %ld sec %ld usec to 0x%x\n", tv.tv_sec, | |
266 | tv.tv_usec, tvaddr); | |
267 | mem_put_si (tvaddr, tv.tv_sec); | |
268 | mem_put_si (tvaddr + 4, tv.tv_usec); | |
269 | put_reg (1, rv); | |
270 | } | |
271 | break; | |
272 | ||
273 | case SYS_kill: | |
274 | { | |
275 | int pid = arg (); | |
276 | int sig = arg (); | |
277 | if (pid == 42) | |
278 | { | |
279 | if (verbose) | |
280 | printf ("[signal %d]\n", sig); | |
281 | return RX_MAKE_STOPPED (sig); | |
282 | } | |
283 | } | |
284 | break; | |
285 | ||
286 | case 11: | |
287 | { | |
288 | int heaptop_arg = arg (); | |
289 | if (trace) | |
290 | printf ("sbrk: heap top set to %x\n", heaptop_arg); | |
291 | heaptop = heaptop_arg; | |
292 | if (heapbottom == 0) | |
293 | heapbottom = heaptop_arg; | |
294 | } | |
295 | break; | |
296 | ||
297 | case 255: | |
298 | { | |
299 | int addr = arg (); | |
300 | mem_put_si (addr, rx_cycles + mem_usage_cycles()); | |
301 | } | |
302 | break; | |
303 | ||
304 | } | |
305 | return RX_MAKE_STEPPED (); | |
306 | } |