Subversion Repositories openrisc_2011-10-31

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

//

//      flash_erase_block.c

//

//      Flash programming

//

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

//####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):    gthomas

// Contributors: gthomas

// Date:         2000-07-14

// Purpose:      

// Description:  

//              

//####DESCRIPTIONEND####

//

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

#include "flash.h"

#include <pkgconf/hal.h>

#include <cyg/hal/hal_arch.h>

#include <cyg/hal/hal_cache.h>

//

// CAUTION!  This code must be copied to RAM before execution.  Therefore,

// it must not contain any code which might be position dependent!

//

int flash_erase_block(volatile unsigned short *block)

{

    volatile unsigned short *ROM, *sb;

    unsigned long stat;

    int timeout = 50000;

    int len, block_size;

    GO_SLOW

    ROM = (volatile unsigned short *)((unsigned long)block & 0xFF800000);

    // Clear any error conditions

    ROM[0] = FLASH_Clear_Status;

    len = FLASH_BLOCK_SIZE;

    if (((unsigned long)block - (unsigned long)ROM) < FLASH_BLOCK_SIZE) {

        block_size = FLASH_BOOT_BLOCK_SIZE;  // First 8 blocks are only 8Kx2 each

    } else {

        block_size = FLASH_BLOCK_SIZE;

    }

    sb = block;

    while (len > 0) {

        // Erase block

        ROM[0] = FLASH_Block_Erase;

        *block = FLASH_Confirm;

        timeout = 5000000;

        while(((stat = ROM[0]) & FLASH_Status_Ready) != FLASH_Status_Ready) {

            if (--timeout == 0) break;

        }

        len -= block_size;

        block += block_size / sizeof(*block);

    }

    // Restore ROM to "normal" mode

    ROM[0] = FLASH_Reset;

    // If an error was reported, see if the block erased anyway

    if (stat & 0x007E007E) {

        len = FLASH_BLOCK_SIZE;

        block = sb;

        while (len > 0) {

            if (*block++ != 0xFFFFFFFF) break;

            len -= sizeof(*block);

        }

        if (len == 0) stat = 0;

    }

    GO_FAST

    return stat;

}