syscall.c

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/*==========================================================================
//
//      syscall.c
//
//      Redboot syscall handling for GNUPro bsp support
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
// This file is part of eCos, the Embedded Configurable Operating System.
// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003 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):    msalter
// Contributors: msalter
// Date:         1999-02-20
// Purpose:      Temporary support for gnupro bsp
//
//####DESCRIPTIONEND####
//
//=========================================================================*/

#include <redboot.h>
#include <cyg/hal/hal_intr.h>
#include <cyg/hal/drv_api.h>
#include <cyg/hal/hal_stub.h>

#ifdef CYGSEM_REDBOOT_BSP_SYSCALLS

#define NEWLIB_EIO 5              /* I/O error */
#define NEWLIB_ENOSYS 88          /* Syscall not supported */

/*
 * Clients of this BSP will need to have access to BSP functions and
 * data structures. Because, the client and the BSP may not be linked
 * together, a structure of vectors is used to gain this access. A
 * pointer to this structure can be gotten via a syscall. This syscall
 * is made automatically from within the crt0.o file.
 */
typedef struct {
    int         version;        /* version number for future expansion */
    const void **__ictrl_table;
    void **__exc_table;
    void *__dbg_vector;
    void *__kill_vector;
    void *__console_procs;
    void *__debug_procs;
    void (*__flush_dcache)(void *__p, int __nbytes);
    void (*__flush_icache)(void *__p, int __nbytes);
    void *__cpu_data;
    void *__board_data;
    void *__sysinfo;
    int  (*__set_debug_comm)(int __comm_id);
    int  (*__set_console_comm)(int __comm_id);
    int  (*__set_serial_baud)(int __comm_id, int baud);
    void *__dbg_data;
    void (*__reset)(void);
    int  __console_interrupt_flag;
} __shared_t;

static __shared_t __shared_data = { 2 };

// this is used by newlib's mode_t so we should match it
#ifdef __GNUC__
#define _ST_INT32 __attribute__ ((__mode__ (__SI__)))
#else
#define _ST_INT32
#endif
typedef unsigned int    newlib_mode_t _ST_INT32;
typedef short           newlib_dev_t;
typedef unsigned short  newlib_ino_t;
typedef unsigned short  newlib_nlink_t;
typedef long            newlib_off_t;
typedef unsigned short  newlib_uid_t;
typedef unsigned short  newlib_gid_t;
typedef long            newlib_time_t;
typedef long            newlib_long_t;

struct newlib_stat 
{
    newlib_dev_t     st_dev;
    newlib_ino_t     st_ino;
    newlib_mode_t    st_mode;
    newlib_nlink_t   st_nlink;
    newlib_uid_t     st_uid;
    newlib_gid_t     st_gid;
    newlib_dev_t     st_rdev;
    newlib_off_t     st_size;
    // We assume we've been compiled with the same flags as newlib here
#if defined(__svr4__) && !defined(__PPC__) && !defined(__sun__)
    newlib_time_t    st_atime;
    newlib_time_t    st_mtime;
    newlib_time_t    st_ctime;
#else
    newlib_time_t    st_atime;
    newlib_long_t    st_spare1;
    newlib_time_t    st_mtime;
    newlib_long_t    st_spare2;
    newlib_time_t    st_ctime;
    newlib_long_t    st_spare3;
    newlib_long_t    st_blksize;
    newlib_long_t    st_blocks;
    newlib_long_t    st_spare4[2];
#endif
};
#define NEWLIB_S_IFCHR 0020000 // character special file

static inline char __getc(void)
{
    char c;
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_CONSOLE_PROCS();
    
    if (__chan)
        c = CYGACC_COMM_IF_GETC(*__chan);
    else {
        __chan = CYGACC_CALL_IF_DEBUG_PROCS();
        c = CYGACC_COMM_IF_GETC(*__chan);
    }
    return c;
}

static inline void __putc(char c)
{
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_CONSOLE_PROCS();
    if (__chan)
        CYGACC_COMM_IF_PUTC(*__chan, c);
    else {
        __chan = CYGACC_CALL_IF_DEBUG_PROCS();
        CYGACC_COMM_IF_PUTC(*__chan, c);
    }
}


static inline void __flush(void)
{
    hal_virtual_comm_table_t* __chan = CYGACC_CALL_IF_CONSOLE_PROCS();

    if (__chan == NULL)
        __chan = CYGACC_CALL_IF_DEBUG_PROCS();

    CYGACC_COMM_IF_CONTROL(*__chan, __COMMCTL_FLUSH_OUTPUT);
}

// Timer support

static cyg_handle_t  sys_timer_handle;
static cyg_interrupt sys_timer_interrupt;
static cyg_uint64    sys_timer_ticks = 0;

#ifdef CYGSEM_REDBOOT_BSP_SYSCALLS_GPROF

static unsigned int set_period = CYGNUM_HAL_RTC_PERIOD; // The default

typedef void *callback_func( char *pc, char *sp );
static callback_func *timer_callback = 0;

#endif // CYGSEM_REDBOOT_BSP_SYSCALLS_GPROF

static void
sys_timer_dsr(cyg_vector_t vector, cyg_ucount32 count, cyg_addrword_t data)
{
    // do nothing
}


static cyg_uint32
sys_timer_isr(cyg_vector_t vector, cyg_addrword_t data)
{
    ++sys_timer_ticks;

#ifdef CYGSEM_REDBOOT_BSP_SYSCALLS_GPROF
    HAL_CLOCK_RESET(CYGNUM_HAL_INTERRUPT_RTC, set_period);
#else
    HAL_CLOCK_RESET(CYGNUM_HAL_INTERRUPT_RTC, CYGNUM_HAL_RTC_PERIOD);
#endif // CYGSEM_REDBOOT_BSP_SYSCALLS_GPROF

    cyg_drv_interrupt_acknowledge(CYGNUM_HAL_INTERRUPT_RTC);

#ifdef CYGSEM_REDBOOT_BSP_SYSCALLS_GPROF
    if ( timer_callback ) {
        char *intrpc = (char *)0;
        char *intrsp = (char *)0;

        // There may be a number of ways to get the PC and (optional) SP
        // information out of the HAL.  Hence this is conditioned.  In some
        // configurations, a register-set pointer is available as
        // (invisible) argument 3 to this ISR call.

#ifdef HAL_GET_PROFILE_INFO
        HAL_GET_PROFILE_INFO( intrpc, intrsp );
#endif // HAL_GET_PROFILE_INFO available

        CYGARC_HAL_SAVE_GP();
        timer_callback( intrpc, intrsp );
        CYGARC_HAL_RESTORE_GP();
    }
#endif // CYGSEM_REDBOOT_BSP_SYSCALLS_GPROF
    return CYG_ISR_HANDLED;
}


static void sys_timer_init(void)
{
#ifdef CYGSEM_REDBOOT_BSP_SYSCALLS_GPROF
    HAL_CLOCK_INITIALIZE(set_period);
#else
    HAL_CLOCK_INITIALIZE(CYGNUM_HAL_RTC_PERIOD);
#endif // CYGSEM_REDBOOT_BSP_SYSCALLS_GPROF
    
    cyg_drv_interrupt_create(
        CYGNUM_HAL_INTERRUPT_RTC,
        0,                      // Priority - unused
        (CYG_ADDRWORD)0,        // Data item passed to ISR & DSR
        sys_timer_isr,          // ISR
        sys_timer_dsr,          // DSR
        &sys_timer_handle,      // handle to intr obj
        &sys_timer_interrupt ); // space for int obj

    cyg_drv_interrupt_attach(sys_timer_handle);

    cyg_drv_interrupt_unmask(CYGNUM_HAL_INTERRUPT_RTC);
}


//
// 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) = __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
    int  tosend;

    tosend = nbytes;

    while (tosend > 0) {
        if (*buf == '\n')
            __putc('\r');
        __putc(*buf++);
        tosend--;
    }
    __flush();

    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 (-NEWLIB_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)
{
    return (-NEWLIB_EIO);
}