target-lm32/lm32-semi.c

   1 /*
   2  *  Lattice Mico32 semihosting syscall interface
   3  *
   4  *  Copyright (c) 2014 Michael Walle <michael@walle.cc>
   5  *
   6  * Based on target-m68k/m68k-semi.c, which is
   7  *  Copyright (c) 2005-2007 CodeSourcery.
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12
  13 #include <errno.h>
  14 #include <unistd.h>
  15 #include <string.h>
  16 #include <stddef.h>
  17 #include "cpu.h"
  18 #include "exec/helper-proto.h"
  19 #include "qemu/log.h"
  20 #include "exec/softmmu-semi.h"
  21
  22 enum {
  23     TARGET_SYS_exit    = 1,
  24     TARGET_SYS_open    = 2,
  25     TARGET_SYS_close   = 3,
  26     TARGET_SYS_read    = 4,
  27     TARGET_SYS_write   = 5,
  28     TARGET_SYS_lseek   = 6,
  29     TARGET_SYS_fstat   = 10,
  30     TARGET_SYS_stat    = 15,
  31 };
  32
  33 enum {
  34     NEWLIB_O_RDONLY    =   0x0,
  35     NEWLIB_O_WRONLY    =   0x1,
  36     NEWLIB_O_RDWR      =   0x2,
  37     NEWLIB_O_APPEND    =   0x8,
  38     NEWLIB_O_CREAT     = 0x200,
  39     NEWLIB_O_TRUNC     = 0x400,
  40     NEWLIB_O_EXCL      = 0x800,
  41 };
  42
  43 static int translate_openflags(int flags)
  44 {
  45     int hf;
  46
  47     if (flags & NEWLIB_O_WRONLY) {
  48         hf = O_WRONLY;
  49     } else if (flags & NEWLIB_O_RDWR) {
  50         hf = O_RDWR;
  51     } else {
  52         hf = O_RDONLY;
  53     }
  54
  55     if (flags & NEWLIB_O_APPEND) {
  56         hf |= O_APPEND;
  57     }
  58
  59     if (flags & NEWLIB_O_CREAT) {
  60         hf |= O_CREAT;
  61     }
  62
  63     if (flags & NEWLIB_O_TRUNC) {
  64         hf |= O_TRUNC;
  65     }
  66
  67     if (flags & NEWLIB_O_EXCL) {
  68         hf |= O_EXCL;
  69     }
  70
  71     return hf;
  72 }
  73
  74 struct newlib_stat {
  75     int16_t     newlib_st_dev;     /* device */
  76     uint16_t    newlib_st_ino;     /* inode */
  77     uint16_t    newlib_st_mode;    /* protection */
  78     uint16_t    newlib_st_nlink;   /* number of hard links */
  79     uint16_t    newlib_st_uid;     /* user ID of owner */
  80     uint16_t    newlib_st_gid;     /* group ID of owner */
  81     int16_t     newlib_st_rdev;    /* device type (if inode device) */
  82     int32_t     newlib_st_size;    /* total size, in bytes */
  83     int32_t     newlib_st_atime;   /* time of last access */
  84     uint32_t    newlib_st_spare1;
  85     int32_t     newlib_st_mtime;   /* time of last modification */
  86     uint32_t    newlib_st_spare2;
  87     int32_t     newlib_st_ctime;   /* time of last change */
  88     uint32_t    newlib_st_spare3;
  89 } QEMU_PACKED;
  90
  91 static int translate_stat(CPULM32State *env, target_ulong addr,
  92         struct stat *s)
  93 {
  94     struct newlib_stat *p;
  95
  96     p = lock_user(VERIFY_WRITE, addr, sizeof(struct newlib_stat), 0);
  97     if (!p) {
  98         return 0;
  99     }
 100     p->newlib_st_dev = cpu_to_be16(s->st_dev);
 101     p->newlib_st_ino = cpu_to_be16(s->st_ino);
 102     p->newlib_st_mode = cpu_to_be16(s->st_mode);
 103     p->newlib_st_nlink = cpu_to_be16(s->st_nlink);
 104     p->newlib_st_uid = cpu_to_be16(s->st_uid);
 105     p->newlib_st_gid = cpu_to_be16(s->st_gid);
 106     p->newlib_st_rdev = cpu_to_be16(s->st_rdev);
 107     p->newlib_st_size = cpu_to_be32(s->st_size);
 108     p->newlib_st_atime = cpu_to_be32(s->st_atime);
 109     p->newlib_st_mtime = cpu_to_be32(s->st_mtime);
 110     p->newlib_st_ctime = cpu_to_be32(s->st_ctime);
 111     unlock_user(p, addr, sizeof(struct newlib_stat));
 112
 113     return 1;
 114 }
 115
 116 bool lm32_cpu_do_semihosting(CPUState *cs)
 117 {
 118     LM32CPU *cpu = LM32_CPU(cs);
 119     CPULM32State *env = &cpu->env;
 120
 121     int ret = -1;
 122     target_ulong nr, arg0, arg1, arg2;
 123     void *p;
 124     struct stat s;
 125
 126     nr = env->regs[R_R8];
 127     arg0 = env->regs[R_R1];
 128     arg1 = env->regs[R_R2];
 129     arg2 = env->regs[R_R3];
 130
 131     switch (nr) {
 132     case TARGET_SYS_exit:
 133         /* void _exit(int rc) */
 134         exit(arg0);
 135
 136     case TARGET_SYS_open:
 137         /* int open(const char *pathname, int flags) */
 138         p = lock_user_string(arg0);
 139         if (!p) {
 140             ret = -1;
 141         } else {
 142             ret = open(p, translate_openflags(arg2));
 143             unlock_user(p, arg0, 0);
 144         }
 145         break;
 146
 147     case TARGET_SYS_read:
 148         /* ssize_t read(int fd, const void *buf, size_t count) */
 149         p = lock_user(VERIFY_WRITE, arg1, arg2, 0);
 150         if (!p) {
 151             ret = -1;
 152         } else {
 153             ret = read(arg0, p, arg2);
 154             unlock_user(p, arg1, arg2);
 155         }
 156         break;
 157
 158     case TARGET_SYS_write:
 159         /* ssize_t write(int fd, const void *buf, size_t count) */
 160         p = lock_user(VERIFY_READ, arg1, arg2, 1);
 161         if (!p) {
 162             ret = -1;
 163         } else {
 164             ret = write(arg0, p, arg2);
 165             unlock_user(p, arg1, 0);
 166         }
 167         break;
 168
 169     case TARGET_SYS_close:
 170         /* int close(int fd) */
 171         /* don't close stdin/stdout/stderr */
 172         if (arg0 > 2) {
 173             ret = close(arg0);
 174         } else {
 175             ret = 0;
 176         }
 177         break;
 178
 179     case TARGET_SYS_lseek:
 180         /* off_t lseek(int fd, off_t offset, int whence */
 181         ret = lseek(arg0, arg1, arg2);
 182         break;
 183
 184     case TARGET_SYS_stat:
 185         /* int stat(const char *path, struct stat *buf) */
 186         p = lock_user_string(arg0);
 187         if (!p) {
 188             ret = -1;
 189         } else {
 190             ret = stat(p, &s);
 191             unlock_user(p, arg0, 0);
 192             if (translate_stat(env, arg1, &s) == 0) {
 193                 ret = -1;
 194             }
 195         }
 196         break;
 197
 198     case TARGET_SYS_fstat:
 199         /* int stat(int fd, struct stat *buf) */
 200         ret = fstat(arg0, &s);
 201         if (ret == 0) {
 202             if (translate_stat(env, arg1, &s) == 0) {
 203                 ret = -1;
 204             }
 205         }
 206         break;
 207
 208     default:
 209         /* unhandled */
 210         return false;
 211     }
 212
 213     env->regs[R_R1] = ret;
 214     return true;
 215 }