flash_lock_block.c

来自「eCos操作系统源码」· C语言 代码 · 共 89 行

//==========================================================================
//
//      flash_lock_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:         2000-12-07
// Purpose:      
// Description:  
//              
//####DESCRIPTIONEND####
//
//==========================================================================

#include "flash.h"
#include <cyg/hal/hal_arch.h>


int
flash_lock_block(volatile unsigned long *block)
	__attribute__ ((section (".2ram.flash_lock_block")));
int
flash_lock_block(volatile unsigned long *block)
{
    volatile unsigned long *ROM;
    unsigned long stat;
    int timeout = 5000000;

    FLASH_WRITE_ENABLE();

    block = (volatile unsigned long *)CYGARC_UNCACHED_ADDRESS((unsigned long)block);
    ROM = (volatile unsigned long *)((unsigned long)block & FLASH_BASE_MASK);

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

    // Set lock bit
    block[0] = FLASH_Set_Lock;
    block[0] = FLASH_Set_Lock_Confirm;  // Confirmation
    while(((stat = ROM[0]) & FLASH_Status_Ready) != FLASH_Status_Ready) {
        if (--timeout == 0) break;
    }

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

    FLASH_WRITE_DISABLE();

    return stat;
}