[mirror_qemu.git] / target / nios2 / nios2-semi.c

/*
 *  Nios II Semihosting syscall interface.
 *  This code is derived from m68k-semi.c.
 *  The semihosting protocol implemented here is described in the
 *  libgloss sources:
 *  https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;a=blob;f=libgloss/nios2/nios2-semi.txt;hb=HEAD
 *
 *  Copyright (c) 2017-2019 Mentor Graphics
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "qemu/osdep.h"

#include "cpu.h"
#include "exec/gdbstub.h"
#if defined(CONFIG_USER_ONLY)
#include "qemu.h"
#else
#include "exec/softmmu-semi.h"
#endif
#include "qemu/log.h"

#define HOSTED_EXIT  0
#define HOSTED_INIT_SIM 1
#define HOSTED_OPEN 2
#define HOSTED_CLOSE 3
#define HOSTED_READ 4
#define HOSTED_WRITE 5
#define HOSTED_LSEEK 6
#define HOSTED_RENAME 7
#define HOSTED_UNLINK 8
#define HOSTED_STAT 9
#define HOSTED_FSTAT 10
#define HOSTED_GETTIMEOFDAY 11
#define HOSTED_ISATTY 12
#define HOSTED_SYSTEM 13

typedef uint32_t gdb_mode_t;
typedef uint32_t gdb_time_t;

struct nios2_gdb_stat {
  uint32_t    gdb_st_dev;     /* device */
  uint32_t    gdb_st_ino;     /* inode */
  gdb_mode_t  gdb_st_mode;    /* protection */
  uint32_t    gdb_st_nlink;   /* number of hard links */
  uint32_t    gdb_st_uid;     /* user ID of owner */
  uint32_t    gdb_st_gid;     /* group ID of owner */
  uint32_t    gdb_st_rdev;    /* device type (if inode device) */
  uint64_t    gdb_st_size;    /* total size, in bytes */
  uint64_t    gdb_st_blksize; /* blocksize for filesystem I/O */
  uint64_t    gdb_st_blocks;  /* number of blocks allocated */
  gdb_time_t  gdb_st_atime;   /* time of last access */
  gdb_time_t  gdb_st_mtime;   /* time of last modification */
  gdb_time_t  gdb_st_ctime;   /* time of last change */
} QEMU_PACKED;

struct gdb_timeval {
  gdb_time_t tv_sec;  /* second */
  uint64_t tv_usec;   /* microsecond */
} QEMU_PACKED;

#define GDB_O_RDONLY   0x0
#define GDB_O_WRONLY   0x1
#define GDB_O_RDWR     0x2
#define GDB_O_APPEND   0x8
#define GDB_O_CREAT  0x200
#define GDB_O_TRUNC  0x400
#define GDB_O_EXCL   0x800

static int translate_openflags(int flags)
{
    int hf;

    if (flags & GDB_O_WRONLY) {
        hf = O_WRONLY;
    } else if (flags & GDB_O_RDWR) {
        hf = O_RDWR;
    } else {
        hf = O_RDONLY;
    }

    if (flags & GDB_O_APPEND) {
        hf |= O_APPEND;
    }
    if (flags & GDB_O_CREAT) {
        hf |= O_CREAT;
    }
    if (flags & GDB_O_TRUNC) {
        hf |= O_TRUNC;
    }
    if (flags & GDB_O_EXCL) {
        hf |= O_EXCL;
    }

    return hf;
}

static bool translate_stat(CPUNios2State *env, target_ulong addr,
                           struct stat *s)
{
    struct nios2_gdb_stat *p;

    p = lock_user(VERIFY_WRITE, addr, sizeof(struct nios2_gdb_stat), 0);

    if (!p) {
        return false;
    }
    p->gdb_st_dev = cpu_to_be32(s->st_dev);
    p->gdb_st_ino = cpu_to_be32(s->st_ino);
    p->gdb_st_mode = cpu_to_be32(s->st_mode);
    p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
    p->gdb_st_uid = cpu_to_be32(s->st_uid);
    p->gdb_st_gid = cpu_to_be32(s->st_gid);
    p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
    p->gdb_st_size = cpu_to_be64(s->st_size);
#ifdef _WIN32
    /* Windows stat is missing some fields.  */
    p->gdb_st_blksize = 0;
    p->gdb_st_blocks = 0;
#else
    p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
    p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
#endif
    p->gdb_st_atime = cpu_to_be32(s->st_atime);
    p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
    p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
    unlock_user(p, addr, sizeof(struct nios2_gdb_stat));
    return true;
}

static void nios2_semi_return_u32(CPUNios2State *env, uint32_t ret,
                                  uint32_t err)
{
    target_ulong args = env->regs[R_ARG1];
    if (put_user_u32(ret, args) ||
        put_user_u32(err, args + 4)) {
        /*
         * The nios2 semihosting ABI does not provide any way to report this
         * error to the guest, so the best we can do is log it in qemu.
         * It is always a guest error not to pass us a valid argument block.
         */
        qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: return value "
                      "discarded because argument block not writable\n");
    }
}

static void nios2_semi_return_u64(CPUNios2State *env, uint64_t ret,
                                  uint32_t err)
{
    target_ulong args = env->regs[R_ARG1];
    if (put_user_u32(ret >> 32, args) ||
        put_user_u32(ret, args + 4) ||
        put_user_u32(err, args + 8)) {
        /* No way to report this via nios2 semihosting ABI; just log it */
        qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: return value "
                      "discarded because argument block not writable\n");
    }
}

static int nios2_semi_is_lseek;

static void nios2_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
{
    Nios2CPU *cpu = NIOS2_CPU(cs);
    CPUNios2State *env = &cpu->env;

    if (nios2_semi_is_lseek) {
        /*
         * FIXME: We've already lost the high bits of the lseek
         * return value.
         */
        nios2_semi_return_u64(env, ret, err);
        nios2_semi_is_lseek = 0;
    } else {
        nios2_semi_return_u32(env, ret, err);
    }
}

/*
 * Read the input value from the argument block; fail the semihosting
 * call if the memory read fails.
 */
#define GET_ARG(n) do {                                 \
    if (get_user_ual(arg ## n, args + (n) * 4)) {       \
        result = -1;                                    \
        errno = EFAULT;                                 \
        goto failed;                                    \
    }                                                   \
} while (0)

void do_nios2_semihosting(CPUNios2State *env)
{
    int nr;
    uint32_t args;
    target_ulong arg0, arg1, arg2, arg3;
    void *p;
    void *q;
    uint32_t len;
    uint32_t result;

    nr = env->regs[R_ARG0];
    args = env->regs[R_ARG1];
    switch (nr) {
    case HOSTED_EXIT:
        gdb_exit(env->regs[R_ARG0]);
        exit(env->regs[R_ARG0]);
    case HOSTED_OPEN:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        GET_ARG(3);
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
                           arg2, arg3);
            return;
        } else {
            p = lock_user_string(arg0);
            if (!p) {
                result = -1;
                errno = EFAULT;
            } else {
                result = open(p, translate_openflags(arg2), arg3);
                unlock_user(p, arg0, 0);
            }
        }
        break;
    case HOSTED_CLOSE:
        {
            /* Ignore attempts to close stdin/out/err.  */
            GET_ARG(0);
            int fd = arg0;
            if (fd > 2) {
                if (use_gdb_syscalls()) {
                    gdb_do_syscall(nios2_semi_cb, "close,%x", arg0);
                    return;
                } else {
                    result = close(fd);
                }
            } else {
                result = 0;
            }
            break;
        }
    case HOSTED_READ:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        len = arg2;
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "read,%x,%x,%x",
                           arg0, arg1, len);
            return;
        } else {
            p = lock_user(VERIFY_WRITE, arg1, len, 0);
            if (!p) {
                result = -1;
                errno = EFAULT;
            } else {
                result = read(arg0, p, len);
                unlock_user(p, arg1, len);
            }
        }
        break;
    case HOSTED_WRITE:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        len = arg2;
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "write,%x,%x,%x",
                           arg0, arg1, len);
            return;
        } else {
            p = lock_user(VERIFY_READ, arg1, len, 1);
            if (!p) {
                result = -1;
                errno = EFAULT;
            } else {
                result = write(arg0, p, len);
                unlock_user(p, arg0, 0);
            }
        }
        break;
    case HOSTED_LSEEK:
        {
            uint64_t off;
            GET_ARG(0);
            GET_ARG(1);
            GET_ARG(2);
            GET_ARG(3);
            off = (uint32_t)arg2 | ((uint64_t)arg1 << 32);
            if (use_gdb_syscalls()) {
                nios2_semi_is_lseek = 1;
                gdb_do_syscall(nios2_semi_cb, "lseek,%x,%lx,%x",
                               arg0, off, arg3);
            } else {
                off = lseek(arg0, off, arg3);
                nios2_semi_return_u64(env, off, errno);
            }
            return;
        }
    case HOSTED_RENAME:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        GET_ARG(3);
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "rename,%s,%s",
                           arg0, (int)arg1, arg2, (int)arg3);
            return;
        } else {
            p = lock_user_string(arg0);
            q = lock_user_string(arg2);
            if (!p || !q) {
                result = -1;
                errno = EFAULT;
            } else {
                result = rename(p, q);
            }
            unlock_user(p, arg0, 0);
            unlock_user(q, arg2, 0);
        }
        break;
    case HOSTED_UNLINK:
        GET_ARG(0);
        GET_ARG(1);
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "unlink,%s",
                           arg0, (int)arg1);
            return;
        } else {
            p = lock_user_string(arg0);
            if (!p) {
                result = -1;
                errno = EFAULT;
            } else {
                result = unlink(p);
                unlock_user(p, arg0, 0);
            }
        }
        break;
    case HOSTED_STAT:
        GET_ARG(0);
        GET_ARG(1);
        GET_ARG(2);
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "stat,%s,%x",
                           arg0, (int)arg1, arg2);
            return;
        } else {
            struct stat s;
            p = lock_user_string(arg0);
            if (!p) {
                result = -1;
                errno = EFAULT;
            } else {
                result = stat(p, &s);
                unlock_user(p, arg0, 0);
            }
            if (result == 0 && !translate_stat(env, arg2, &s)) {
                result = -1;
                errno = EFAULT;
            }
        }
        break;
    case HOSTED_FSTAT:
        GET_ARG(0);
        GET_ARG(1);
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "fstat,%x,%x",
                           arg0, arg1);
            return;
        } else {
            struct stat s;
            result = fstat(arg0, &s);
            if (result == 0 && !translate_stat(env, arg1, &s)) {
                result = -1;
                errno = EFAULT;
            }
        }
        break;
    case HOSTED_GETTIMEOFDAY:
        /* Only the tv parameter is used.  tz is assumed NULL.  */
        GET_ARG(0);
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "gettimeofday,%x,%x",
                           arg0, 0);
            return;
        } else {
            struct gdb_timeval *p;
            int64_t rt = g_get_real_time();
            p = lock_user(VERIFY_WRITE, arg0, sizeof(struct gdb_timeval), 0);
            if (!p) {
                result = -1;
                errno = EFAULT;
            } else {
                result = 0;
                p->tv_sec = cpu_to_be32(rt / G_USEC_PER_SEC);
                p->tv_usec = cpu_to_be64(rt % G_USEC_PER_SEC);
                unlock_user(p, arg0, sizeof(struct gdb_timeval));
            }
        }
        break;
    case HOSTED_ISATTY:
        GET_ARG(0);
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "isatty,%x", arg0);
            return;
        } else {
            result = isatty(arg0);
        }
        break;
    case HOSTED_SYSTEM:
        GET_ARG(0);
        GET_ARG(1);
        if (use_gdb_syscalls()) {
            gdb_do_syscall(nios2_semi_cb, "system,%s",
                           arg0, (int)arg1);
            return;
        } else {
            p = lock_user_string(arg0);
            if (!p) {
                result = -1;
                errno = EFAULT;
            } else {
                result = system(p);
                unlock_user(p, arg0, 0);
            }
        }
        break;
    default:
        qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: unsupported "
                      "semihosting syscall %d\n", nr);
        result = 0;
    }
failed:
    nios2_semi_return_u32(env, result, errno);
}
Commit	Line	Data
413a99a9 SL	1	/*
	2	* Nios II Semihosting syscall interface.
	3	* This code is derived from m68k-semi.c.
	4	* The semihosting protocol implemented here is described in the
	5	* libgloss sources:
	6	* https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;a=blob;f=libgloss/nios2/nios2-semi.txt;hb=HEAD
	7	*
	8	* Copyright (c) 2017-2019 Mentor Graphics
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2 of the License, or
	13	* (at your option) any later version.
	14	*
	15	* This program is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	* GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	22	*/
	23
	24	#include "qemu/osdep.h"
	25
	26	#include "cpu.h"
85b4fa0c	27	#include "exec/gdbstub.h"
413a99a9 SL	28	#if defined(CONFIG_USER_ONLY)
	29	#include "qemu.h"
	30	#else
413a99a9 SL	31	#include "exec/softmmu-semi.h"
	32	#endif
	33	#include "qemu/log.h"
413a99a9 SL	34
	35	#define HOSTED_EXIT 0
	36	#define HOSTED_INIT_SIM 1
	37	#define HOSTED_OPEN 2
	38	#define HOSTED_CLOSE 3
	39	#define HOSTED_READ 4
	40	#define HOSTED_WRITE 5
	41	#define HOSTED_LSEEK 6
	42	#define HOSTED_RENAME 7
	43	#define HOSTED_UNLINK 8
	44	#define HOSTED_STAT 9
	45	#define HOSTED_FSTAT 10
	46	#define HOSTED_GETTIMEOFDAY 11
	47	#define HOSTED_ISATTY 12
	48	#define HOSTED_SYSTEM 13
	49
	50	typedef uint32_t gdb_mode_t;
	51	typedef uint32_t gdb_time_t;
	52
	53	struct nios2_gdb_stat {
	54	uint32_t gdb_st_dev; /* device */
	55	uint32_t gdb_st_ino; /* inode */
	56	gdb_mode_t gdb_st_mode; /* protection */
	57	uint32_t gdb_st_nlink; /* number of hard links */
	58	uint32_t gdb_st_uid; /* user ID of owner */
	59	uint32_t gdb_st_gid; /* group ID of owner */
	60	uint32_t gdb_st_rdev; /* device type (if inode device) */
	61	uint64_t gdb_st_size; /* total size, in bytes */
	62	uint64_t gdb_st_blksize; /* blocksize for filesystem I/O */
	63	uint64_t gdb_st_blocks; /* number of blocks allocated */
	64	gdb_time_t gdb_st_atime; /* time of last access */
	65	gdb_time_t gdb_st_mtime; /* time of last modification */
	66	gdb_time_t gdb_st_ctime; /* time of last change */
	67	} QEMU_PACKED;
	68
	69	struct gdb_timeval {
	70	gdb_time_t tv_sec; /* second */
	71	uint64_t tv_usec; /* microsecond */
	72	} QEMU_PACKED;
	73
	74	#define GDB_O_RDONLY 0x0
	75	#define GDB_O_WRONLY 0x1
	76	#define GDB_O_RDWR 0x2
	77	#define GDB_O_APPEND 0x8
	78	#define GDB_O_CREAT 0x200
	79	#define GDB_O_TRUNC 0x400
	80	#define GDB_O_EXCL 0x800
	81
	82	static int translate_openflags(int flags)
	83	{
	84	int hf;
	85
	86	if (flags & GDB_O_WRONLY) {
	87	hf = O_WRONLY;
	88	} else if (flags & GDB_O_RDWR) {
	89	hf = O_RDWR;
	90	} else {
	91	hf = O_RDONLY;
	92	}
	93
	94	if (flags & GDB_O_APPEND) {
	95	hf \|= O_APPEND;
	96	}
	97	if (flags & GDB_O_CREAT) {
98	hf \|= O_CREAT;
99	}
100	if (flags & GDB_O_TRUNC) {
101	hf \|= O_TRUNC;
102	}
103	if (flags & GDB_O_EXCL) {
104	hf \|= O_EXCL;
105	}
106
107	return hf;
108	}
109
110	static bool translate_stat(CPUNios2State *env, target_ulong addr,
111	struct stat *s)
112	{
113	struct nios2_gdb_stat *p;
114
115	p = lock_user(VERIFY_WRITE, addr, sizeof(struct nios2_gdb_stat), 0);
116
117	if (!p) {
118	return false;
119	}
120	p->gdb_st_dev = cpu_to_be32(s->st_dev);
121	p->gdb_st_ino = cpu_to_be32(s->st_ino);
122	p->gdb_st_mode = cpu_to_be32(s->st_mode);
123	p->gdb_st_nlink = cpu_to_be32(s->st_nlink);
124	p->gdb_st_uid = cpu_to_be32(s->st_uid);
125	p->gdb_st_gid = cpu_to_be32(s->st_gid);
126	p->gdb_st_rdev = cpu_to_be32(s->st_rdev);
127	p->gdb_st_size = cpu_to_be64(s->st_size);
128	#ifdef _WIN32
129	/* Windows stat is missing some fields. */
130	p->gdb_st_blksize = 0;
131	p->gdb_st_blocks = 0;
132	#else
133	p->gdb_st_blksize = cpu_to_be64(s->st_blksize);
134	p->gdb_st_blocks = cpu_to_be64(s->st_blocks);
135	#endif
136	p->gdb_st_atime = cpu_to_be32(s->st_atime);
137	p->gdb_st_mtime = cpu_to_be32(s->st_mtime);
138	p->gdb_st_ctime = cpu_to_be32(s->st_ctime);
139	unlock_user(p, addr, sizeof(struct nios2_gdb_stat));
140	return true;
141	}
142
143	static void nios2_semi_return_u32(CPUNios2State *env, uint32_t ret,
144	uint32_t err)
145	{
146	target_ulong args = env->regs[R_ARG1];
147	if (put_user_u32(ret, args) \|\|
148	put_user_u32(err, args + 4)) {
149	/*
150	* The nios2 semihosting ABI does not provide any way to report this
151	* error to the guest, so the best we can do is log it in qemu.
152	* It is always a guest error not to pass us a valid argument block.
153	*/
154	qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: return value "
155	"discarded because argument block not writable\n");
156	}
157	}
158
159	static void nios2_semi_return_u64(CPUNios2State *env, uint64_t ret,
160	uint32_t err)
161	{
162	target_ulong args = env->regs[R_ARG1];
163	if (put_user_u32(ret >> 32, args) \|\|
164	put_user_u32(ret, args + 4) \|\|
165	put_user_u32(err, args + 8)) {
166	/* No way to report this via nios2 semihosting ABI; just log it */
167	qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: return value "
168	"discarded because argument block not writable\n");
169	}
170	}
171
172	static int nios2_semi_is_lseek;
173
174	static void nios2_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
175	{
176	Nios2CPU *cpu = NIOS2_CPU(cs);
177	CPUNios2State *env = &cpu->env;
178
179	if (nios2_semi_is_lseek) {
180	/*
181	* FIXME: We've already lost the high bits of the lseek
182	* return value.
183	*/
184	nios2_semi_return_u64(env, ret, err);
185	nios2_semi_is_lseek = 0;
186	} else {
187	nios2_semi_return_u32(env, ret, err);
188	}
189	}
190
191	/*
192	* Read the input value from the argument block; fail the semihosting
193	* call if the memory read fails.
194	*/
195	#define GET_ARG(n) do { \
196	if (get_user_ual(arg ## n, args + (n) * 4)) { \
197	result = -1; \
198	errno = EFAULT; \
199	goto failed; \
200	} \
201	} while (0)
202
203	void do_nios2_semihosting(CPUNios2State *env)
204	{
205	int nr;
206	uint32_t args;
207	target_ulong arg0, arg1, arg2, arg3;
208	void *p;
209	void *q;
210	uint32_t len;
211	uint32_t result;
212
213	nr = env->regs[R_ARG0];
214	args = env->regs[R_ARG1];
215	switch (nr) {
216	case HOSTED_EXIT:
ad9dcb20	217	gdb_exit(env->regs[R_ARG0]);
413a99a9 SL	218	exit(env->regs[R_ARG0]);
	219	case HOSTED_OPEN:
	220	GET_ARG(0);
	221	GET_ARG(1);
	222	GET_ARG(2);
	223	GET_ARG(3);
	224	if (use_gdb_syscalls()) {
	225	gdb_do_syscall(nios2_semi_cb, "open,%s,%x,%x", arg0, (int)arg1,
	226	arg2, arg3);
	227	return;
	228	} else {
	229	p = lock_user_string(arg0);
	230	if (!p) {
	231	result = -1;
	232	errno = EFAULT;
	233	} else {
	234	result = open(p, translate_openflags(arg2), arg3);
	235	unlock_user(p, arg0, 0);
	236	}
	237	}
	238	break;
	239	case HOSTED_CLOSE:
	240	{
	241	/* Ignore attempts to close stdin/out/err. */
	242	GET_ARG(0);
	243	int fd = arg0;
	244	if (fd > 2) {
	245	if (use_gdb_syscalls()) {
	246	gdb_do_syscall(nios2_semi_cb, "close,%x", arg0);
	247	return;
	248	} else {
	249	result = close(fd);
	250	}
	251	} else {
	252	result = 0;
	253	}
	254	break;
	255	}
	256	case HOSTED_READ:
	257	GET_ARG(0);
	258	GET_ARG(1);
	259	GET_ARG(2);
	260	len = arg2;
	261	if (use_gdb_syscalls()) {
	262	gdb_do_syscall(nios2_semi_cb, "read,%x,%x,%x",
	263	arg0, arg1, len);
	264	return;
	265	} else {
	266	p = lock_user(VERIFY_WRITE, arg1, len, 0);
	267	if (!p) {
	268	result = -1;
	269	errno = EFAULT;
	270	} else {
	271	result = read(arg0, p, len);
	272	unlock_user(p, arg1, len);
	273	}
	274	}
	275	break;
	276	case HOSTED_WRITE:
	277	GET_ARG(0);
	278	GET_ARG(1);
	279	GET_ARG(2);
	280	len = arg2;
	281	if (use_gdb_syscalls()) {
282	gdb_do_syscall(nios2_semi_cb, "write,%x,%x,%x",
283	arg0, arg1, len);
284	return;
285	} else {
286	p = lock_user(VERIFY_READ, arg1, len, 1);
287	if (!p) {
288	result = -1;
289	errno = EFAULT;
290	} else {
291	result = write(arg0, p, len);
292	unlock_user(p, arg0, 0);
293	}
294	}
295	break;
296	case HOSTED_LSEEK:
297	{
298	uint64_t off;
299	GET_ARG(0);
300	GET_ARG(1);
301	GET_ARG(2);
302	GET_ARG(3);
303	off = (uint32_t)arg2 \| ((uint64_t)arg1 << 32);
304	if (use_gdb_syscalls()) {
305	nios2_semi_is_lseek = 1;
306	gdb_do_syscall(nios2_semi_cb, "lseek,%x,%lx,%x",
307	arg0, off, arg3);
308	} else {
309	off = lseek(arg0, off, arg3);
310	nios2_semi_return_u64(env, off, errno);
311	}
312	return;
313	}
314	case HOSTED_RENAME:
315	GET_ARG(0);
316	GET_ARG(1);
317	GET_ARG(2);
318	GET_ARG(3);
319	if (use_gdb_syscalls()) {
320	gdb_do_syscall(nios2_semi_cb, "rename,%s,%s",
321	arg0, (int)arg1, arg2, (int)arg3);
322	return;
323	} else {
324	p = lock_user_string(arg0);
325	q = lock_user_string(arg2);
326	if (!p \|\| !q) {
327	result = -1;
328	errno = EFAULT;
329	} else {
330	result = rename(p, q);
331	}
332	unlock_user(p, arg0, 0);
333	unlock_user(q, arg2, 0);
334	}
335	break;
336	case HOSTED_UNLINK:
337	GET_ARG(0);
338	GET_ARG(1);
339	if (use_gdb_syscalls()) {
340	gdb_do_syscall(nios2_semi_cb, "unlink,%s",
341	arg0, (int)arg1);
342	return;
343	} else {
344	p = lock_user_string(arg0);
345	if (!p) {
346	result = -1;
347	errno = EFAULT;
348	} else {
349	result = unlink(p);
350	unlock_user(p, arg0, 0);
351	}
352	}
353	break;
354	case HOSTED_STAT:
355	GET_ARG(0);
356	GET_ARG(1);
357	GET_ARG(2);
358	if (use_gdb_syscalls()) {
359	gdb_do_syscall(nios2_semi_cb, "stat,%s,%x",
360	arg0, (int)arg1, arg2);
361	return;
362	} else {
363	struct stat s;
364	p = lock_user_string(arg0);
365	if (!p) {
366	result = -1;
367	errno = EFAULT;
368	} else {
369	result = stat(p, &s);
370	unlock_user(p, arg0, 0);
371	}
372	if (result == 0 && !translate_stat(env, arg2, &s)) {
373	result = -1;
374	errno = EFAULT;
375	}
376	}
377	break;
378	case HOSTED_FSTAT:
379	GET_ARG(0);
380	GET_ARG(1);
381	if (use_gdb_syscalls()) {
382	gdb_do_syscall(nios2_semi_cb, "fstat,%x,%x",
383	arg0, arg1);
384	return;
385	} else {
386	struct stat s;
387	result = fstat(arg0, &s);
388	if (result == 0 && !translate_stat(env, arg1, &s)) {
389	result = -1;
390	errno = EFAULT;
391	}
392	}
393	break;
394	case HOSTED_GETTIMEOFDAY:
395	/* Only the tv parameter is used. tz is assumed NULL. */
396	GET_ARG(0);
397	if (use_gdb_syscalls()) {
398	gdb_do_syscall(nios2_semi_cb, "gettimeofday,%x,%x",
399	arg0, 0);
400	return;
401	} else {
413a99a9	402	struct gdb_timeval *p;
f793dde0 MAL	403	int64_t rt = g_get_real_time();
	404	p = lock_user(VERIFY_WRITE, arg0, sizeof(struct gdb_timeval), 0);
	405	if (!p) {
	406	result = -1;
	407	errno = EFAULT;
	408	} else {
	409	result = 0;
	410	p->tv_sec = cpu_to_be32(rt / G_USEC_PER_SEC);
	411	p->tv_usec = cpu_to_be64(rt % G_USEC_PER_SEC);
	412	unlock_user(p, arg0, sizeof(struct gdb_timeval));
413a99a9 SL	413	}
	414	}
	415	break;
	416	case HOSTED_ISATTY:
	417	GET_ARG(0);
	418	if (use_gdb_syscalls()) {
	419	gdb_do_syscall(nios2_semi_cb, "isatty,%x", arg0);
	420	return;
	421	} else {
	422	result = isatty(arg0);
	423	}
	424	break;
	425	case HOSTED_SYSTEM:
	426	GET_ARG(0);
	427	GET_ARG(1);
	428	if (use_gdb_syscalls()) {
	429	gdb_do_syscall(nios2_semi_cb, "system,%s",
	430	arg0, (int)arg1);
	431	return;
	432	} else {
	433	p = lock_user_string(arg0);
	434	if (!p) {
	435	result = -1;
	436	errno = EFAULT;
	437	} else {
	438	result = system(p);
	439	unlock_user(p, arg0, 0);
	440	}
	441	}
	442	break;
	443	default:
	444	qemu_log_mask(LOG_GUEST_ERROR, "nios2-semihosting: unsupported "
	445	"semihosting syscall %d\n", nr);
	446	result = 0;
	447	}
	448	failed:
	449	nios2_semi_return_u32(env, result, errno);
	450	}