target/m68k/m68k-semi.c

   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  *  The semihosting protocol implemented here is described in the
  20  *  libgloss sources:
  21  *  https://sourceware.org/git/?p=newlib-cygwin.git;a=blob;f=libgloss/m68k/m68k-semi.txt;hb=HEAD
  22  */
  23
  24 #include "qemu/osdep.h"
  25
  26 #include "cpu.h"
  27 #include "gdbstub/syscalls.h"
  28 #include "gdbstub/helpers.h"
  29 #include "semihosting/syscalls.h"
  30 #include "semihosting/uaccess.h"
  31 #include "hw/boards.h"
  32 #include "qemu/log.h"
  33
  34 #define HOSTED_EXIT  0
  35 #define HOSTED_INIT_SIM 1
  36 #define HOSTED_OPEN 2
  37 #define HOSTED_CLOSE 3
  38 #define HOSTED_READ 4
  39 #define HOSTED_WRITE 5
  40 #define HOSTED_LSEEK 6
  41 #define HOSTED_RENAME 7
  42 #define HOSTED_UNLINK 8
  43 #define HOSTED_STAT 9
  44 #define HOSTED_FSTAT 10
  45 #define HOSTED_GETTIMEOFDAY 11
  46 #define HOSTED_ISATTY 12
  47 #define HOSTED_SYSTEM 13
  48
  49 static int host_to_gdb_errno(int err)
  50 {
  51 #define E(X)  case E##X: return GDB_E##X
  52     switch (err) {
  53     E(PERM);
  54     E(NOENT);
  55     E(INTR);
  56     E(BADF);
  57     E(ACCES);
  58     E(FAULT);
  59     E(BUSY);
  60     E(EXIST);
  61     E(NODEV);
  62     E(NOTDIR);
  63     E(ISDIR);
  64     E(INVAL);
  65     E(NFILE);
  66     E(MFILE);
  67     E(FBIG);
  68     E(NOSPC);
  69     E(SPIPE);
  70     E(ROFS);
  71     E(NAMETOOLONG);
  72     default:
  73         return GDB_EUNKNOWN;
  74     }
  75 #undef E
  76 }
  77
  78 static void m68k_semi_u32_cb(CPUState *cs, uint64_t ret, int err)
  79 {
  80     CPUM68KState *env = cpu_env(cs);
  81
  82     target_ulong args = env->dregs[1];
  83     if (put_user_u32(ret, args) ||
  84         put_user_u32(host_to_gdb_errno(err), args + 4)) {
  85         /*
  86          * The m68k semihosting ABI does not provide any way to report this
  87          * error to the guest, so the best we can do is log it in qemu.
  88          * It is always a guest error not to pass us a valid argument block.
  89          */
  90         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
  91                       "discarded because argument block not writable\n");
  92     }
  93 }
  94
  95 static void m68k_semi_u64_cb(CPUState *cs, uint64_t ret, int err)
  96 {
  97     CPUM68KState *env = cpu_env(cs);
  98
  99     target_ulong args = env->dregs[1];
 100     if (put_user_u32(ret >> 32, args) ||
 101         put_user_u32(ret, args + 4) ||
 102         put_user_u32(host_to_gdb_errno(err), args + 8)) {
 103         /* No way to report this via m68k semihosting ABI; just log it */
 104         qemu_log_mask(LOG_GUEST_ERROR, "m68k-semihosting: return value "
 105                       "discarded because argument block not writable\n");
 106     }
 107 }
 108
 109 /*
 110  * Read the input value from the argument block; fail the semihosting
 111  * call if the memory read fails.
 112  */
 113 #define GET_ARG(n) do {                                 \
 114     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 115         goto failed;                                    \
 116     }                                                   \
 117 } while (0)
 118
 119 #define GET_ARG64(n) do {                               \
 120     if (get_user_ual(arg ## n, args + (n) * 4)) {       \
 121         goto failed64;                                  \
 122     }                                                   \
 123 } while (0)
 124
 125
 126 void do_m68k_semihosting(CPUM68KState *env, int nr)
 127 {
 128     CPUState *cs = env_cpu(env);
 129     uint32_t args;
 130     target_ulong arg0, arg1, arg2, arg3;
 131
 132     args = env->dregs[1];
 133     switch (nr) {
 134     case HOSTED_EXIT:
 135         gdb_exit(env->dregs[1]);
 136         exit(env->dregs[1]);
 137
 138     case HOSTED_OPEN:
 139         GET_ARG(0);
 140         GET_ARG(1);
 141         GET_ARG(2);
 142         GET_ARG(3);
 143         semihost_sys_open(cs, m68k_semi_u32_cb, arg0, arg1, arg2, arg3);
 144         break;
 145
 146     case HOSTED_CLOSE:
 147         GET_ARG(0);
 148         semihost_sys_close(cs, m68k_semi_u32_cb, arg0);
 149         break;
 150
 151     case HOSTED_READ:
 152         GET_ARG(0);
 153         GET_ARG(1);
 154         GET_ARG(2);
 155         semihost_sys_read(cs, m68k_semi_u32_cb, arg0, arg1, arg2);
 156         break;
 157
 158     case HOSTED_WRITE:
 159         GET_ARG(0);
 160         GET_ARG(1);
 161         GET_ARG(2);
 162         semihost_sys_write(cs, m68k_semi_u32_cb, arg0, arg1, arg2);
 163         break;
 164
 165     case HOSTED_LSEEK:
 166         GET_ARG64(0);
 167         GET_ARG64(1);
 168         GET_ARG64(2);
 169         GET_ARG64(3);
 170         semihost_sys_lseek(cs, m68k_semi_u64_cb, arg0,
 171                            deposit64(arg2, 32, 32, arg1), arg3);
 172         break;
 173
 174     case HOSTED_RENAME:
 175         GET_ARG(0);
 176         GET_ARG(1);
 177         GET_ARG(2);
 178         GET_ARG(3);
 179         semihost_sys_rename(cs, m68k_semi_u32_cb, arg0, arg1, arg2, arg3);
 180         break;
 181
 182     case HOSTED_UNLINK:
 183         GET_ARG(0);
 184         GET_ARG(1);
 185         semihost_sys_remove(cs, m68k_semi_u32_cb, arg0, arg1);
 186         break;
 187
 188     case HOSTED_STAT:
 189         GET_ARG(0);
 190         GET_ARG(1);
 191         GET_ARG(2);
 192         semihost_sys_stat(cs, m68k_semi_u32_cb, arg0, arg1, arg2);
 193         break;
 194
 195     case HOSTED_FSTAT:
 196         GET_ARG(0);
 197         GET_ARG(1);
 198         semihost_sys_fstat(cs, m68k_semi_u32_cb, arg0, arg1);
 199         break;
 200
 201     case HOSTED_GETTIMEOFDAY:
 202         GET_ARG(0);
 203         GET_ARG(1);
 204         semihost_sys_gettimeofday(cs, m68k_semi_u32_cb, arg0, arg1);
 205         break;
 206
 207     case HOSTED_ISATTY:
 208         GET_ARG(0);
 209         semihost_sys_isatty(cs, m68k_semi_u32_cb, arg0);
 210         break;
 211
 212     case HOSTED_SYSTEM:
 213         GET_ARG(0);
 214         GET_ARG(1);
 215         semihost_sys_system(cs, m68k_semi_u32_cb, arg0, arg1);
 216         break;
 217
 218     case HOSTED_INIT_SIM:
 219         /*
 220          * FIXME: This is wrong for boards where RAM does not start at
 221          * address zero.
 222          */
 223         env->dregs[1] = current_machine->ram_size;
 224         env->aregs[7] = current_machine->ram_size;
 225         return;
 226
 227     default:
 228         cpu_abort(env_cpu(env), "Unsupported semihosting syscall %d\n", nr);
 229
 230     failed:
 231         m68k_semi_u32_cb(cs, -1, EFAULT);
 232         break;
 233     failed64:
 234         m68k_semi_u64_cb(cs, -1, EFAULT);
 235         break;
 236     }
 237 }