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//==========================================================================

//

//      syscall.c

//

//      Minimal generic syscall support.

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos 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 or (at your option) any later version.

//

// eCos 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 eCos; if not, write to the Free Software Foundation, Inc.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

// License. However the source code for this file must still be made available

// in accordance with section (3) of the GNU General Public License.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    

// Contributors: gthomas

// Date:         1999-10-20

// Purpose:      Minimal generic syscall support.

// Description:  

//               

//

//####DESCRIPTIONEND####

//

//=========================================================================

#include <errno.h>

#include <bsp/cpu.h>

#include <bsp/bsp.h>

#include "bsp_if.h"

#include "syscall.h"

/*

 * read  -- read bytes from the serial port. Ignore fd, since

 *          we only have stdin.

 */

static int

sys_read(int fd, char *buf, int nbytes)

{

    int i = 0;

    for (i = 0; i < nbytes; i++) {

        *(buf + i) = bsp_console_getc();

        if ((*(buf + i) == '\n') || (*(buf + i) == '\r')) {

            (*(buf + i + 1)) = 0;

            break;

        }

    }

    return (i);

}

/*

 * write -- write bytes to the serial port. Ignore fd, since

 *          stdout and stderr are the same. Since we have no filesystem,

 *          open will only return an error.

 */

static int

sys_write(int fd, char *buf, int nbytes)

{

#define WBUFSIZE  256

    char ch, lbuf[WBUFSIZE];

    int  i, tosend;

    tosend = nbytes;

    while (tosend > 0) {

        for (i = 0; tosend > 0 && i < (WBUFSIZE-2); tosend--) {

            ch = *buf++;

            if (ch == '\n')

                lbuf[i++] = '\r';

            lbuf[i++] = ch;

        }

        bsp_console_write(lbuf, i);

    }

    return (nbytes);

}

/*

 * open -- open a file descriptor. We don't have a filesystem, so

 *         we return an error.

 */

static int

sys_open (const char *buf, int flags, int mode)

{

    return (-EIO);

}

/*

 * close -- We don't need to do anything, but pretend we did.

 */

static int

sys_close(int fd)

{

    return (0);

}

/*

 * lseek --  Since a serial port is non-seekable, we return an error.

 */

static int

sys_lseek(int fd,  int offset, int whence)

{

#ifdef ESPIPE

    return (-ESPIPE);

#else

    return (-EIO);

#endif

}

/*

 *  Generic syscall handler.

 *

 *  Returns 0 if syscall number is not handled by this

 *  module, 1 otherwise. This allows applications to

 *  extend the syscall handler by using exception chaining.

 */

int

_bsp_do_syscall(int func,               /* syscall function number */

                long arg1, long arg2,   /* up to four args.        */

                long arg3, long arg4,

                int *retval)            /* syscall return value    */

{

    int err = 0;

    switch (func) {

      case SYS_read:

        err = sys_read((int)arg1, (char *)arg2, (int)arg3);

        break;

      case SYS_write:

        err = sys_write((int)arg1, (char *)arg2, (int)arg3);

        break;

      case SYS_open:

        err = sys_open((const char *)arg1, (int)arg2, (int)arg3);

        break;

      case SYS_close:

        err = sys_close((int)arg1);

        break;

      case SYS_lseek:

        err = sys_lseek((int)arg1, (int)arg2, (int)arg3);

        break;

      case BSP_GET_SHARED:

        *(bsp_shared_t **)arg1 = bsp_shared_data;

        break;

      case SYS_meminfo:

        {

          // Return the top and size of memory.

          struct bsp_mem_info      mem;

          int                      i;

          unsigned long            u, totmem, topmem, numbanks;

          i = totmem = topmem = numbanks = 0;

          while (bsp_sysinfo(BSP_INFO_MEMORY, i++, &mem) == 0)

            {

              if (mem.kind == BSP_MEM_RAM)

                {

                  numbanks++;

                  totmem += mem.nbytes;

                  u = (unsigned long)mem.virt_start + mem.nbytes;

                  if (u > topmem)

                    topmem = u;

                }

            }

          *(unsigned long *)arg1 = totmem;

          *(unsigned long *)arg2 = topmem;

          *retval = numbanks;

        }

        return 1;

        break;

      default:

        return 0;

    }

    *retval = err;

    return 1;

}