flash_erase_block.c

基于ecos的redboot

//==========================================================================
//
//      flash_erase_block.c
//
//      Flash programming
//
//==========================================================================
//####COPYRIGHTBEGIN####
//                                                                          
// -------------------------------------------                              
// The contents of this file are subject to the Red Hat eCos Public License 
// Version 1.1 (the "License"); you may not use this file except in         
// compliance with the License.  You may obtain a copy of the License at    
// http://www.redhat.com/                                                   
//                                                                          
// Software distributed under the License is distributed on an "AS IS"      
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
// License for the specific language governing rights and limitations under 
// the License.                                                             
//                                                                          
// The Original Code is eCos - Embedded Configurable Operating System,      
// released September 30, 1998.                                             
//                                                                          
// The Initial Developer of the Original Code is Red Hat.                   
// Portions created by Red Hat are                                          
// Copyright (C) 1998, 1999, 2000, 2001 Red Hat, Inc.
// All Rights Reserved.                                                     
// -------------------------------------------                              
//                                                                          
//####COPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    gthomas, hmt
// Contributors: gthomas
// Date:         2001-02-14
// Purpose:      
// Description:  
//              
//####DESCRIPTIONEND####
//
//==========================================================================

#include "strata.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 flash_t *block, unsigned int block_size)
{
    volatile flash_t *ROM;
    flash_t stat = 0;
    int timeout = 50000;
    int cache_on;
    int len, block_len, erase_block_size;
    volatile flash_t *eb;

    HAL_DCACHE_IS_ENABLED(cache_on);
    if (cache_on) {
        HAL_DCACHE_SYNC();
        HAL_DCACHE_DISABLE();
    }

    // Get base address and map addresses to virtual addresses
    ROM = FLASH_P2V(CYGNUM_FLASH_BASE_MASK & (unsigned int)block);
    eb = block = FLASH_P2V(block);
    block_len = block_size;

#ifdef CYGOPT_FLASH_IS_BOOTBLOCK
#define BLOCKSIZE (0x10000*CYGNUM_FLASH_DEVICES)
#define ERASE_BLOCKSIZE (0x2000*CYGNUM_FLASH_DEVICES)
    if ((eb - ROM) < BLOCKSIZE) {
// FIXME - Handle 'boot' blocks
        erase_block_size = ERASE_BLOCKSIZE;
    } else {
        erase_block_size = block_size;
    }
#else
    erase_block_size = block_size;
#endif

    // Clear any error conditions
    ROM[0] = FLASH_Clear_Status;

    // Erase block
    while (block_len > 0) {
        ROM[0] = FLASH_Block_Erase;
        *eb = FLASH_Confirm;
        timeout = 5000000;
        while(((stat = ROM[0]) & FLASH_Status_Ready) != FLASH_Status_Ready) {
            if (--timeout == 0) break;
        }
        block_len -= erase_block_size;
        eb = FLASH_P2V((unsigned int)eb + erase_block_size);
    }

    // Restore ROM to "normal" mode
    ROM[0] = FLASH_Reset;

    // If an error was reported, see if the block erased anyway
    if (stat & FLASH_ErrorMask ) {
        len = block_size;
        while (len > 0) {
            if (*block++ != FLASH_BlankValue ) break;
            len -= sizeof(*block);
        }
        if (len == 0) stat = 0;
    }

    if (cache_on) {
        HAL_DCACHE_ENABLE();
    }

    return stat;
}