/*
 *  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, see <http://www.gnu.org/licenses/>.
 */

#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 = set_swi_errno(ts, open(s, open_modeflags[ARG(1)], 0644));
        }
        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, 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 {
                return write(STDERR_FILENO, &c, 1);
          }
        }
    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 = write(STDERR_FILENO, s, len);
        }
        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, 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;
            do
              ret = set_swi_errno(ts, read(ARG(0), s, len));
            while (ret == -1 && errno == EINTR);
            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 *arm_cmdline_buffer;
            const char *host_cmdline_buffer;

            unsigned int i;
            unsigned int arm_cmdline_len = ARG(1);
            unsigned int host_cmdline_len =
                ts->info->arg_end-ts->info->arg_start;

            if (!arm_cmdline_len || host_cmdline_len > arm_cmdline_len) {
                return -1; /* not enough space to store command line */
            }

            if (!host_cmdline_len) {
                /* We special-case the "empty command line" case (argc==0).
                   Just provide the terminating 0. */
                arm_cmdline_buffer = lock_user(VERIFY_WRITE, ARG(0), 1, 0);
                arm_cmdline_buffer[0] = 0;
                unlock_user(arm_cmdline_buffer, ARG(0), 1);

                /* Adjust the commandline length argument. */
                SET_ARG(1, 0);
                return 0;
            }

            /* lock the buffers on the ARM side */
            arm_cmdline_buffer =
                lock_user(VERIFY_WRITE, ARG(0), host_cmdline_len, 0);
            host_cmdline_buffer =
                lock_user(VERIFY_READ, ts->info->arg_start,
                                       host_cmdline_len, 1);

            if (arm_cmdline_buffer && host_cmdline_buffer)
            {
                /* the last argument is zero-terminated;
                   no need for additional termination */
                memcpy(arm_cmdline_buffer, host_cmdline_buffer,
                       host_cmdline_len);

                /* separate arguments by white spaces */
                for (i = 0; i < host_cmdline_len-1; i++) {
                    if (arm_cmdline_buffer[i] == 0) {
                        arm_cmdline_buffer[i] = ' ';
                    }
                }

                /* Adjust the commandline length argument. */
                SET_ARG(1, host_cmdline_len-1);
            }

            /* Unlock the buffers on the ARM side.  */
            unlock_user(arm_cmdline_buffer, ARG(0), host_cmdline_len);
            unlock_user((void*)host_cmdline_buffer, ts->info->arg_start, 0);

            /* Return success if we could return a commandline.  */
            return (arm_cmdline_buffer && host_cmdline_buffer) ? 0 : -1;
        }
#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:
        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();
    }
}
