/*

 *  Arm "Angel" semihosting syscalls

 *

 *  Copyright (c) 2005, 2007 CodeSourcery.

 *  Written by Paul Brook.

 *

 *  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, write to the Free Software

 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 */

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <unistd.h>

#include <stdlib.h>

#include <stdio.h>

#include <time.h>

#include "cpu.h"

#ifdef CONFIG_USER_ONLY

#include "qemu.h"

#define ARM_ANGEL_HEAP_SIZE (128 * 1024 * 1024)

#else

#include "qemu-common.h"

#include "sysemu.h"

#include "gdbstub.h"

#endif

#define SYS_OPEN        0x01

#define SYS_CLOSE       0x02

#define SYS_WRITEC      0x03

#define SYS_WRITE0      0x04

#define SYS_WRITE       0x05

#define SYS_READ        0x06

#define SYS_READC       0x07

#define SYS_ISTTY       0x09

#define SYS_SEEK        0x0a

#define SYS_FLEN        0x0c

#define SYS_TMPNAM      0x0d

#define SYS_REMOVE      0x0e

#define SYS_RENAME      0x0f

#define SYS_CLOCK       0x10

#define SYS_TIME        0x11

#define SYS_SYSTEM      0x12

#define SYS_ERRNO       0x13

#define SYS_GET_CMDLINE 0x15

#define SYS_HEAPINFO    0x16

#define SYS_EXIT        0x18

#ifndef O_BINARY

#define O_BINARY 0

#endif

#define GDB_O_RDONLY  0x000

#define GDB_O_WRONLY  0x001

#define GDB_O_RDWR    0x002

#define GDB_O_APPEND  0x008

#define GDB_O_CREAT   0x200

#define GDB_O_TRUNC   0x400

#define GDB_O_BINARY  0

static int gdb_open_modeflags[12] = {

    GDB_O_RDONLY,

    GDB_O_RDONLY | GDB_O_BINARY,

    GDB_O_RDWR,

    GDB_O_RDWR | GDB_O_BINARY,

    GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC,

    GDB_O_WRONLY | GDB_O_CREAT | GDB_O_TRUNC | GDB_O_BINARY,

    GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC,

    GDB_O_RDWR | GDB_O_CREAT | GDB_O_TRUNC | GDB_O_BINARY,

    GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND,

    GDB_O_WRONLY | GDB_O_CREAT | GDB_O_APPEND | GDB_O_BINARY,

    GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND,

    GDB_O_RDWR | GDB_O_CREAT | GDB_O_APPEND | GDB_O_BINARY

};

static int open_modeflags[12] = {

    O_RDONLY,

    O_RDONLY | O_BINARY,

    O_RDWR,

    O_RDWR | O_BINARY,

    O_WRONLY | O_CREAT | O_TRUNC,

    O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,

    O_RDWR | O_CREAT | O_TRUNC,

    O_RDWR | O_CREAT | O_TRUNC | O_BINARY,

    O_WRONLY | O_CREAT | O_APPEND,

    O_WRONLY | O_CREAT | O_APPEND | O_BINARY,

    O_RDWR | O_CREAT | O_APPEND,

    O_RDWR | O_CREAT | O_APPEND | O_BINARY

};

#ifdef CONFIG_USER_ONLY

static inline uint32_t set_swi_errno(TaskState *ts, uint32_t code)

{

    if (code == (uint32_t)-1)

        ts->swi_errno = errno;

    return code;

}

#else

static inline uint32_t set_swi_errno(CPUState *env, uint32_t code)

{

    return code;

}

#include "softmmu-semi.h"

#endif

static target_ulong arm_semi_syscall_len;

#if !defined(CONFIG_USER_ONLY)

static target_ulong syscall_err;

#endif

static void arm_semi_cb(CPUState *env, target_ulong ret, target_ulong err)

{

#ifdef CONFIG_USER_ONLY

    TaskState *ts = env->opaque;

#endif

    if (ret == (target_ulong)-1) {

#ifdef CONFIG_USER_ONLY

        ts->swi_errno = err;

#else

	syscall_err = err;

#endif

        env->regs[0] = ret;

    } else {

        /* Fixup syscalls that use nonstardard return conventions.  */

        switch (env->regs[0]) {

        case SYS_WRITE:

        case SYS_READ:

            env->regs[0] = arm_semi_syscall_len - ret;

            break;

        case SYS_SEEK:

            env->regs[0] = 0;

            break;

        default:

            env->regs[0] = ret;

            break;

        }

    }

}

static void arm_semi_flen_cb(CPUState *env, target_ulong ret, target_ulong err)

{

    /* The size is always stored in big-endian order, extract

       the value. We assume the size always fit in 32 bits.  */

    uint32_t size;

    cpu_memory_rw_debug(env, env->regs[13]-64+32, (uint8_t *)&size, 4, 0);

    env->regs[0] = be32_to_cpu(size);

#ifdef CONFIG_USER_ONLY

    ((TaskState *)env->opaque)->swi_errno = err;

#else

    syscall_err = err;

#endif

}

#define ARG(n)					\

({						\

    target_ulong __arg;				\

    /* FIXME - handle get_user() failure */	\

    get_user_ual(__arg, args + (n) * 4);	\

    __arg;					\

})

#define SET_ARG(n, val) put_user_ual(val, args + (n) * 4)

uint32_t do_arm_semihosting(CPUState *env)

{

    target_ulong args;

    char * s;

    int nr;

    uint32_t ret;

    uint32_t len;

#ifdef CONFIG_USER_ONLY

    TaskState *ts = env->opaque;

#else

    CPUState *ts = env;

#endif

    nr = env->regs[0];

    args = env->regs[1];

    switch (nr) {

    case SYS_OPEN:

        if (!(s = lock_user_string(ARG(0))))

            /* FIXME - should this error code be -TARGET_EFAULT ? */

            return (uint32_t)-1;

        if (ARG(1) >= 12)

            return (uint32_t)-1;

        if (strcmp(s, ":tt") == 0) {

            if (ARG(1) < 4)

                return STDIN_FILENO;

            else

                return STDOUT_FILENO;

        }

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_cb, "open,%s,%x,1a4", ARG(0),

			   (int)ARG(2)+1, gdb_open_modeflags[ARG(1)]);

            return env->regs[0];

        } else {

	    ret = uninterrupted_open(s, open_modeflags[ARG(1)], 0644);

            ret = set_swi_errno(ts, ret);

        }

        unlock_user(s, ARG(0), 0);

        return ret;

    case SYS_CLOSE:

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_cb, "close,%x", ARG(0));

            return env->regs[0];

        } else {

	    return set_swi_errno(ts, uninterrupted_close(ARG(0)));

        }

    case SYS_WRITEC:

        {

          char c;

          if (get_user_u8(c, args))

              /* FIXME - should this error code be -TARGET_EFAULT ? */

              return (uint32_t)-1;

          /* Write to debug console.  stderr is near enough.  */

          if (use_gdb_syscalls()) {

                gdb_do_syscall(arm_semi_cb, "write,2,%x,1", args);

                return env->regs[0];

          } else {

	      ret = uninterrupted_write(STDERR_FILENO, &c, 1);

	      return set_swi_errno(ts, ret);

          }

        }

    case SYS_WRITE0:

        if (!(s = lock_user_string(args)))

            /* FIXME - should this error code be -TARGET_EFAULT ? */

            return (uint32_t)-1;

        len = strlen(s);

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_cb, "write,2,%x,%x\n", args, len);

            ret = env->regs[0];

        } else {

	    ret = uninterrupted_write(STDERR_FILENO, s, len);

	    ret = set_swi_errno(ts, ret);

        }

        unlock_user(s, args, 0);

        return ret;

    case SYS_WRITE:

        len = ARG(2);

        if (use_gdb_syscalls()) {

            arm_semi_syscall_len = len;

            gdb_do_syscall(arm_semi_cb, "write,%x,%x,%x", ARG(0), ARG(1), len);

            return env->regs[0];

        } else {

            if (!(s = lock_user(VERIFY_READ, ARG(1), len, 1)))

                /* FIXME - should this error code be -TARGET_EFAULT ? */

                return (uint32_t)-1;

	    ret = set_swi_errno(ts, uninterrupted_write(ARG(0), s, len));

            unlock_user(s, ARG(1), 0);

            if (ret == (uint32_t)-1)

                return -1;

            return len - ret;

        }

    case SYS_READ:

        len = ARG(2);

        if (use_gdb_syscalls()) {

            arm_semi_syscall_len = len;

            gdb_do_syscall(arm_semi_cb, "read,%x,%x,%x", ARG(0), ARG(1), len);

            return env->regs[0];

        } else {

            if (!(s = lock_user(VERIFY_WRITE, ARG(1), len, 0)))

                /* FIXME - should this error code be -TARGET_EFAULT ? */

                return (uint32_t)-1;

	    ret = set_swi_errno(ts, uninterrupted_read(ARG(0), s, len));

            unlock_user(s, ARG(1), len);

            if (ret == (uint32_t)-1)

                return -1;

            return len - ret;

        }

    case SYS_READC:

       /* XXX: Read from debug cosole. Not implemented.  */

        return 0;

    case SYS_ISTTY:

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_cb, "isatty,%x", ARG(0));

            return env->regs[0];

        } else {

            return isatty(ARG(0));

        }

    case SYS_SEEK:

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_cb, "lseek,%x,%x,0", ARG(0), ARG(1));

            return env->regs[0];

        } else {

            ret = set_swi_errno(ts, lseek(ARG(0), ARG(1), SEEK_SET));

            if (ret == (uint32_t)-1)

              return -1;

            return 0;

        }

    case SYS_FLEN:

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_flen_cb, "fstat,%x,%x",

			   ARG(0), env->regs[13]-64);

            return env->regs[0];

        } else {

            struct stat buf;

            ret = set_swi_errno(ts, fstat(ARG(0), &buf));

            if (ret == (uint32_t)-1)

                return -1;

            return buf.st_size;

        }

    case SYS_TMPNAM:

        /* XXX: Not implemented.  */

        return -1;

    case SYS_REMOVE:

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_cb, "unlink,%s", ARG(0), (int)ARG(1)+1);

            ret = env->regs[0];

        } else {

            if (!(s = lock_user_string(ARG(0))))

                /* FIXME - should this error code be -TARGET_EFAULT ? */

                return (uint32_t)-1;

            ret =  set_swi_errno(ts, remove(s));

            unlock_user(s, ARG(0), 0);

        }

        return ret;

    case SYS_RENAME:

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_cb, "rename,%s,%s",

                           ARG(0), (int)ARG(1)+1, ARG(2), (int)ARG(3)+1);

            return env->regs[0];

        } else {

            char *s2;

            s = lock_user_string(ARG(0));

            s2 = lock_user_string(ARG(2));

            if (!s || !s2)

                /* FIXME - should this error code be -TARGET_EFAULT ? */

                ret = (uint32_t)-1;

            else

                ret = set_swi_errno(ts, rename(s, s2));

            if (s2)

                unlock_user(s2, ARG(2), 0);

            if (s)

                unlock_user(s, ARG(0), 0);

            return ret;

        }

    case SYS_CLOCK:

        return clock() / (CLOCKS_PER_SEC / 100);

    case SYS_TIME:

        return set_swi_errno(ts, time(NULL));

    case SYS_SYSTEM:

        if (use_gdb_syscalls()) {

            gdb_do_syscall(arm_semi_cb, "system,%s", ARG(0), (int)ARG(1)+1);

            return env->regs[0];

        } else {

            if (!(s = lock_user_string(ARG(0))))

                /* FIXME - should this error code be -TARGET_EFAULT ? */

                return (uint32_t)-1;

            ret = set_swi_errno(ts, system(s));

            unlock_user(s, ARG(0), 0);

            return ret;

        }

    case SYS_ERRNO:

#ifdef CONFIG_USER_ONLY

        return ts->swi_errno;

#else

        return syscall_err;

#endif

    case SYS_GET_CMDLINE:

#ifdef CONFIG_USER_ONLY

        /* Build a commandline from the original argv.  */

        {

            char **arg = ts->info->host_argv;

            int len = ARG(1);

            /* lock the buffer on the ARM side */

            char *cmdline_buffer = (char*)lock_user(VERIFY_WRITE, ARG(0), len, 0);

            if (!cmdline_buffer)

                /* FIXME - should this error code be -TARGET_EFAULT ? */

                return (uint32_t)-1;

            s = cmdline_buffer;

            while (*arg && len > 2) {

                int n = strlen(*arg);

                if (s != cmdline_buffer) {

                    *(s++) = ' ';

                    len--;

                }

                if (n >= len)

                    n = len - 1;

                memcpy(s, *arg, n);

                s += n;

                len -= n;

                arg++;

            }

            /* Null terminate the string.  */

            *s = 0;

            len = s - cmdline_buffer;

            /* Unlock the buffer on the ARM side.  */

            unlock_user(cmdline_buffer, ARG(0), len);

            /* Adjust the commandline length argument.  */

            SET_ARG(1, len);

            /* Return success if commandline fit into buffer.  */

            return *arg ? -1 : 0;

        }

#else

      return -1;

#endif

    case SYS_HEAPINFO:

        {

            uint32_t *ptr;

            uint32_t limit;

#ifdef CONFIG_USER_ONLY

            /* Some C libraries assume the heap immediately follows .bss, so

               allocate it using sbrk.  */

            if (!ts->heap_limit) {

                long ret;

                ts->heap_base = do_brk(0);

                limit = ts->heap_base + ARM_ANGEL_HEAP_SIZE;

                /* Try a big heap, and reduce the size if that fails.  */

                for (;;) {

                    ret = do_brk(limit);

                    if (ret != -1)

                        break;

                    limit = (ts->heap_base >> 1) + (limit >> 1);

                }

                ts->heap_limit = limit;

            }

            if (!(ptr = lock_user(VERIFY_WRITE, ARG(0), 16, 0)))

                /* FIXME - should this error code be -TARGET_EFAULT ? */

                return (uint32_t)-1;

            ptr[0] = tswap32(ts->heap_base);

            ptr[1] = tswap32(ts->heap_limit);

            ptr[2] = tswap32(ts->stack_base);

            ptr[3] = tswap32(0); /* Stack limit.  */

            unlock_user(ptr, ARG(0), 16);

#else

            limit = ram_size;

            if (!(ptr = lock_user(VERIFY_WRITE, ARG(0), 16, 0)))

                /* FIXME - should this error code be -TARGET_EFAULT ? */

                return (uint32_t)-1;

            /* TODO: Make this use the limit of the loaded application.  */

            ptr[0] = tswap32(limit / 2);

            ptr[1] = tswap32(limit);

            ptr[2] = tswap32(limit); /* Stack base */

            ptr[3] = tswap32(0); /* Stack limit.  */

            unlock_user(ptr, ARG(0), 16);

#endif

            return 0;

        }

    case SYS_EXIT:

        /* FIXME: ideally we want to inform gdb about program

	   exit whenever gdb is connected, even if syscalls

	   are not handled by gdb.  */

        if (use_gdb_syscalls())

            gdb_exit(env, 0);

        exit(0);

    default:

        fprintf(stderr, "qemu: Unsupported SemiHosting SWI 0x%02x\n", nr);

        cpu_dump_state(env, stderr, fprintf, 0);

        abort();

    }

}