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

//

//      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, msalter

// 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 char *block)

{

    volatile unsigned char *ROM;

    unsigned short stat;

    int timeout = 50000;

    int cache_on;

    int len;

    HAL_DCACHE_IS_ENABLED(cache_on);

    if (cache_on) {

        HAL_DCACHE_SYNC();

        HAL_DCACHE_DISABLE();

    }

    // First 4K page of flash at physcial address zero is

    // virtually mapped to address 0xa0000000.

    ROM = FLASH_P2V((unsigned)block & 0xFF800000);

    // Clear any error conditions

    ROM[0] = FLASH_Clear_Status;

    // Erase block

    ROM[0] = FLASH_Block_Erase;

    *FLASH_P2V(block) = FLASH_Confirm;

    timeout = 5000000;

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

        if (--timeout == 0) break;

    }

    // Restore ROM to "normal" mode

    ROM[0] = FLASH_Reset;

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

    if (stat & 0x7E) {

        len = FLASH_BLOCK_SIZE;

        while (len > 0) {

            if (*FLASH_P2V(block) != 0xFF)

                break;

            block++;

            len -= sizeof(*block);

        }

        if (len == 0) stat = 0;

    }

    if (cache_on) {

        HAL_DCACHE_ENABLE();

    }

    return stat;

}