flash_program_buf.c

Intel XScale PXA255 引导Linux的Redboot 版bootloader源代码！

//==========================================================================
//
//      flash_program_buf.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 Red Hat, Inc.                             
// All Rights Reserved.                                                     
// -------------------------------------------                              
//                                                                          
//####COPYRIGHTEND####
//==========================================================================
//#####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_program_buf(volatile unsigned short *addr, unsigned short *data, int len)
{
    volatile unsigned short *ROM;
    unsigned short stat = 0;
    int timeout = 50000;

    GO_SLOW

    ROM = (volatile unsigned short *)((unsigned long)addr & 0xFF800000);
    // Clear any error conditions
    ROM[0] = FLASH_Clear_Status;

    while (len > 0) {
        ROM[0] = FLASH_Program;
        *addr = *data;
        timeout = 5000000;
        while(((stat = ROM[0]) & FLASH_Status_Ready) != FLASH_Status_Ready) {
            if (--timeout == 0) {
                goto bad;
            }
        }
        if (stat & 0x007E) {
            break;
        }
        ROM[0] = FLASH_Reset;            
        if (*addr++ != *data++) {
            stat = 0x9910;
            break;
        }
        len -= 2;
    }

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

    GO_FAST

    return stat;
}