1 /*
2  *  m68k/ColdFire Semihosting syscall interface
3  *
4  *  Copyright (c) 2005-2007 CodeSourcery.
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 
22 #include "cpu.h"
23 #include "exec/gdbstub.h"
24 #if defined(CONFIG_USER_ONLY)
25 #include "qemu.h"
26 #define SEMIHOSTING_HEAP_SIZE (128 * 1024 * 1024)
27 #else
28 #include "exec/softmmu-semi.h"
29 #include "hw/boards.h"
30 #endif
31 #include "qemu/log.h"
32 
33 #define HOSTED_EXIT  0
34 #define HOSTED_INIT_SIM 1
35 #define HOSTED_OPEN 2
36 #define HOSTED_CLOSE 3
37 #define HOSTED_READ 4
38 #define HOSTED_WRITE 5
39 #define HOSTED_LSEEK 6
40 #define HOSTED_RENAME 7
41 #define HOSTED_UNLINK 8
42 #define HOSTED_STAT 9
43 #define HOSTED_FSTAT 10
44 #define HOSTED_GETTIMEOFDAY 11
45 #define HOSTED_ISATTY 12
46 #define HOSTED_SYSTEM 13
47 
48 typedef uint32_t gdb_mode_t;
49 typedef uint32_t gdb_time_t;
50 
51 struct m68k_gdb_stat {
52   uint32_t    gdb_st_dev;     /* device */
53   uint32_t    gdb_st_ino;     /* inode */
54   gdb_mode_t  gdb_st_mode;    /* protection */
55   uint32_t    gdb_st_nlink;   /* number of hard links */
56   uint32_t    gdb_st_uid;     /* user ID of owner */
57   uint32_t    gdb_st_gid;     /* group ID of owner */
58   uint32_t    gdb_st_rdev;    /* device type (if inode device) */
59   uint64_t    gdb_st_size;    /* total size, in bytes */
60   uint64_t    gdb_st_blksize; /* blocksize for filesystem I/O */
61   uint64_t    gdb_st_blocks;  /* number of blocks allocated */
62   gdb_time_t  gdb_st_atime;   /* time of last access */
63   gdb_time_t  gdb_st_mtime;   /* time of last modification */
64   gdb_time_t  gdb_st_ctime;   /* time of last change */
65 } QEMU_PACKED;
66 
67 struct gdb_timeval {
68   gdb_time_t tv_sec;  /* second */
69   uint64_t tv_usec;   /* microsecond */
70 } QEMU_PACKED;
71 
72 #define GDB_O_RDONLY   0x0
73 #define GDB_O_WRONLY   0x1
74 #define GDB_O_RDWR     0x2
75 #define GDB_O_APPEND   0x8
76 #define GDB_O_CREAT  0x200
77 #define GDB_O_TRUNC  0x400
78 #define GDB_O_EXCL   0x800
79 
translate_openflags(int flags)80 static int translate_openflags(int flags)
81 {
82     int hf;
83 
84     if (flags & GDB_O_WRONLY)
85         hf = O_WRONLY;
86     else if (flags & GDB_O_RDWR)
87         hf = O_RDWR;
88     else
89         hf = O_RDONLY;
90 
91     if (flags & GDB_O_APPEND) hf |= O_APPEND;
92     if (flags & GDB_O_CREAT) hf |= O_CREAT;
93     if (flags & GDB_O_TRUNC) hf |= O_TRUNC;
94     if (flags & GDB_O_EXCL) hf |= O_EXCL;
95 
96     return hf;
97 }
98 
translate_stat(CPUM68KState * env,target_ulong addr,struct stat * s)99 static void translate_stat(CPUM68KState *env, target_ulong addr, struct stat *s)
100 {
101     struct m68k_gdb_stat *p;
102 
103     if (!(p = lock_user(VERIFY_WRITE, addr, sizeof(struct m68k_gdb_stat), 0)))
104         /* FIXME - should this return an error code? */
105         return;
106     p->gdb_st_dev = cpu_to_be32(s->st_dev);
107     p->gdb_st_ino = cpu_to_be32(s->st_ino);
108     p->gdb_st_mode = cpu_to_be32(s->st_mode);
109     p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
110     p->gdb_st_uid = cpu_to_be32(s->st_uid);
111     p->gdb_st_gid = cpu_to_be32(s->st_gid);
112     p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
113     p->gdb_st_size = cpu_to_be64(s->st_size);
114 #ifdef _WIN32
115     /* Windows stat is missing some fields.  */
116     p->gdb_st_blksize = 0;
117     p->gdb_st_blocks = 0;
118 #else
119     p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
120     p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
121 #endif
122     p->gdb_st_atime = cpu_to_be32(s->st_atime);
123     p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
124     p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
125     unlock_user(p, addr, sizeof(struct m68k_gdb_stat));
126 }
127 
m68k_semi_return_u32(CPUM68KState * env,uint32_t ret,uint32_t err)128 static void m68k_semi_return_u32(CPUM68KState *env, uint32_t ret, uint32_t err)
129 {
130     target_ulong args = env->dregs[1];
131     if (put_user_u32(ret, args) ||
132         put_user_u32(err, args + 4)) {
133         /*
134          * The m68k semihosting ABI does not provide any way to report this
135          * error to the guest, so the best we can do is log it in qemu.
136          * It is always a guest error not to pass us a valid argument block.
137          */
138         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
139                       "discarded because argument block not writable\n");
140     }
141 }
142 
m68k_semi_return_u64(CPUM68KState * env,uint64_t ret,uint32_t err)143 static void m68k_semi_return_u64(CPUM68KState *env, uint64_t ret, uint32_t err)
144 {
145     target_ulong args = env->dregs[1];
146     if (put_user_u32(ret >> 32, args) ||
147         put_user_u32(ret, args + 4) ||
148         put_user_u32(err, args + 8)) {
149         /* No way to report this via m68k semihosting ABI; just log it */
150         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
151                       "discarded because argument block not writable\n");
152     }
153 }
154 
155 static int m68k_semi_is_fseek;
156 
m68k_semi_cb(CPUState * cs,target_ulong ret,target_ulong err)157 static void m68k_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
158 {
159     M68kCPU *cpu = M68K_CPU(cs);
160     CPUM68KState *env = &cpu->env;
161 
162     if (m68k_semi_is_fseek) {
163         /*
164          * FIXME: We've already lost the high bits of the fseek
165          * return value.
166          */
167         m68k_semi_return_u64(env, ret, err);
168         m68k_semi_is_fseek = 0;
169     } else {
170         m68k_semi_return_u32(env, ret, err);
171     }
172 }
173 
174 /*
175  * Read the input value from the argument block; fail the semihosting
176  * call if the memory read fails.
177  */
178 #define GET_ARG(n) do {                                 \
179     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
180         result = -1;                                    \
181         errno = EFAULT;                                 \
182         goto failed;                                    \
183     }                                                   \
184 } while (0)
185 
do_m68k_semihosting(CPUM68KState * env,int nr)186 void do_m68k_semihosting(CPUM68KState *env, int nr)
187 {
188     uint32_t args;
189     target_ulong arg0, arg1, arg2, arg3;
190     void *p;
191     void *q;
192     uint32_t len;
193     uint32_t result;
194 
195     args = env->dregs[1];
196     switch (nr) {
197     case HOSTED_EXIT:
198         gdb_exit(env->dregs[0]);
199         exit(env->dregs[0]);
200     case HOSTED_OPEN:
201         GET_ARG(0);
202         GET_ARG(1);
203         GET_ARG(2);
204         GET_ARG(3);
205         if (use_gdb_syscalls()) {
206             gdb_do_syscall(m68k_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
207                            arg2, arg3);
208             return;
209         } else {
210             p = lock_user_string(arg0);
211             if (!p) {
212                 /* FIXME - check error code? */
213                 result = -1;
214             } else {
215                 result = open(p, translate_openflags(arg2), arg3);
216                 unlock_user(p, arg0, 0);
217             }
218         }
219         break;
220     case HOSTED_CLOSE:
221         {
222             /* Ignore attempts to close stdin/out/err.  */
223             GET_ARG(0);
224             int fd = arg0;
225             if (fd > 2) {
226                 if (use_gdb_syscalls()) {
227                     gdb_do_syscall(m68k_semi_cb, "close,%x", arg0);
228                     return;
229                 } else {
230                     result = close(fd);
231                 }
232             } else {
233                 result = 0;
234             }
235             break;
236         }
237     case HOSTED_READ:
238         GET_ARG(0);
239         GET_ARG(1);
240         GET_ARG(2);
241         len = arg2;
242         if (use_gdb_syscalls()) {
243             gdb_do_syscall(m68k_semi_cb, "read,%x,%x,%x",
244                            arg0, arg1, len);
245             return;
246         } else {
247             p = lock_user(VERIFY_WRITE, arg1, len, 0);
248             if (!p) {
249                 /* FIXME - check error code? */
250                 result = -1;
251             } else {
252                 result = read(arg0, p, len);
253                 unlock_user(p, arg1, len);
254             }
255         }
256         break;
257     case HOSTED_WRITE:
258         GET_ARG(0);
259         GET_ARG(1);
260         GET_ARG(2);
261         len = arg2;
262         if (use_gdb_syscalls()) {
263             gdb_do_syscall(m68k_semi_cb, "write,%x,%x,%x",
264                            arg0, arg1, len);
265             return;
266         } else {
267             p = lock_user(VERIFY_READ, arg1, len, 1);
268             if (!p) {
269                 /* FIXME - check error code? */
270                 result = -1;
271             } else {
272                 result = write(arg0, p, len);
273                 unlock_user(p, arg0, 0);
274             }
275         }
276         break;
277     case HOSTED_LSEEK:
278         {
279             uint64_t off;
280             GET_ARG(0);
281             GET_ARG(1);
282             GET_ARG(2);
283             GET_ARG(3);
284             off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
285             if (use_gdb_syscalls()) {
286                 m68k_semi_is_fseek = 1;
287                 gdb_do_syscall(m68k_semi_cb, "fseek,%x,%lx,%x",
288                                arg0, off, arg3);
289             } else {
290                 off = lseek(arg0, off, arg3);
291                 m68k_semi_return_u64(env, off, errno);
292             }
293             return;
294         }
295     case HOSTED_RENAME:
296         GET_ARG(0);
297         GET_ARG(1);
298         GET_ARG(2);
299         GET_ARG(3);
300         if (use_gdb_syscalls()) {
301             gdb_do_syscall(m68k_semi_cb, "rename,%s,%s",
302                            arg0, (int)arg1, arg2, (int)arg3);
303             return;
304         } else {
305             p = lock_user_string(arg0);
306             q = lock_user_string(arg2);
307             if (!p || !q) {
308                 /* FIXME - check error code? */
309                 result = -1;
310             } else {
311                 result = rename(p, q);
312             }
313             unlock_user(p, arg0, 0);
314             unlock_user(q, arg2, 0);
315         }
316         break;
317     case HOSTED_UNLINK:
318         GET_ARG(0);
319         GET_ARG(1);
320         if (use_gdb_syscalls()) {
321             gdb_do_syscall(m68k_semi_cb, "unlink,%s",
322                            arg0, (int)arg1);
323             return;
324         } else {
325             p = lock_user_string(arg0);
326             if (!p) {
327                 /* FIXME - check error code? */
328                 result = -1;
329             } else {
330                 result = unlink(p);
331                 unlock_user(p, arg0, 0);
332             }
333         }
334         break;
335     case HOSTED_STAT:
336         GET_ARG(0);
337         GET_ARG(1);
338         GET_ARG(2);
339         if (use_gdb_syscalls()) {
340             gdb_do_syscall(m68k_semi_cb, "stat,%s,%x",
341                            arg0, (int)arg1, arg2);
342             return;
343         } else {
344             struct stat s;
345             p = lock_user_string(arg0);
346             if (!p) {
347                 /* FIXME - check error code? */
348                 result = -1;
349             } else {
350                 result = stat(p, &s);
351                 unlock_user(p, arg0, 0);
352             }
353             if (result == 0) {
354                 translate_stat(env, arg2, &s);
355             }
356         }
357         break;
358     case HOSTED_FSTAT:
359         GET_ARG(0);
360         GET_ARG(1);
361         if (use_gdb_syscalls()) {
362             gdb_do_syscall(m68k_semi_cb, "fstat,%x,%x",
363                            arg0, arg1);
364             return;
365         } else {
366             struct stat s;
367             result = fstat(arg0, &s);
368             if (result == 0) {
369                 translate_stat(env, arg1, &s);
370             }
371         }
372         break;
373     case HOSTED_GETTIMEOFDAY:
374         GET_ARG(0);
375         GET_ARG(1);
376         if (use_gdb_syscalls()) {
377             gdb_do_syscall(m68k_semi_cb, "gettimeofday,%x,%x",
378                            arg0, arg1);
379             return;
380         } else {
381             qemu_timeval tv;
382             struct gdb_timeval *p;
383             result = qemu_gettimeofday(&tv);
384             if (result != 0) {
385                 if (!(p = lock_user(VERIFY_WRITE,
386                                     arg0, sizeof(struct gdb_timeval), 0))) {
387                     /* FIXME - check error code? */
388                     result = -1;
389                 } else {
390                     p->tv_sec = cpu_to_be32(tv.tv_sec);
391                     p->tv_usec = cpu_to_be64(tv.tv_usec);
392                     unlock_user(p, arg0, sizeof(struct gdb_timeval));
393                 }
394             }
395         }
396         break;
397     case HOSTED_ISATTY:
398         GET_ARG(0);
399         if (use_gdb_syscalls()) {
400             gdb_do_syscall(m68k_semi_cb, "isatty,%x", arg0);
401             return;
402         } else {
403             result = isatty(arg0);
404         }
405         break;
406     case HOSTED_SYSTEM:
407         GET_ARG(0);
408         GET_ARG(1);
409         if (use_gdb_syscalls()) {
410             gdb_do_syscall(m68k_semi_cb, "system,%s",
411                            arg0, (int)arg1);
412             return;
413         } else {
414             p = lock_user_string(arg0);
415             if (!p) {
416                 /* FIXME - check error code? */
417                 result = -1;
418             } else {
419                 result = system(p);
420                 unlock_user(p, arg0, 0);
421             }
422         }
423         break;
424     case HOSTED_INIT_SIM:
425 #if defined(CONFIG_USER_ONLY)
426         {
427         CPUState *cs = env_cpu(env);
428         TaskState *ts = cs->opaque;
429         /* Allocate the heap using sbrk.  */
430         if (!ts->heap_limit) {
431             abi_ulong ret;
432             uint32_t size;
433             uint32_t base;
434 
435             base = do_brk(0);
436             size = SEMIHOSTING_HEAP_SIZE;
437             /* Try a big heap, and reduce the size if that fails.  */
438             for (;;) {
439                 ret = do_brk(base + size);
440                 if (ret >= (base + size)) {
441                     break;
442                 }
443                 size >>= 1;
444             }
445             ts->heap_limit = base + size;
446         }
447         /*
448          * This call may happen before we have writable memory, so return
449          * values directly in registers.
450          */
451         env->dregs[1] = ts->heap_limit;
452         env->aregs[7] = ts->stack_base;
453         }
454 #else
455         /*
456          * FIXME: This is wrong for boards where RAM does not start at
457          * address zero.
458          */
459         env->dregs[1] = current_machine->ram_size;
460         env->aregs[7] = current_machine->ram_size;
461 #endif
462         return;
463     default:
464         cpu_abort(env_cpu(env), "Unsupported semihosting syscall %d\n", nr);
465         result = 0;
466     }
467 failed:
468     m68k_semi_return_u32(env, result, errno);
469 }
470