flash.h

针对德州仪器DM270开发板的bootloader,其实现了内核的下载以及文件系统的下载

/*
 * File: flash.h
 *
 * This is an interface to a utility which allows the caller to read and
 * write to non-volatile flash memory. This is an abstraction of generic
 * flash and the functionality presented by this interface is independent
 * of the actual device utilized. The module which is implemented to expose
 * this generic interface will handle the specifics of the physical flash
 * components utilized.
 *
 * See Also
 *   flash_intel.c   -- An implementation exposing a flash.h interface.
 *   flash_toshiba.c -- An implementation exposing a flash.h interface.
 *
 * Copyright (C) 2002 RidgeRun, Inc.
 * Author: RidgeRun, Inc  <[e-mail]>
 *
 *  This program 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 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS  PROVIDED  ``AS  IS''  AND   ANY  EXPRESS  OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT,  INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Please report all bugs/problems to the author or <[e-mail]>
 *
 * key: RRGPLCR (do not remove)
 *
 */

#ifndef FLASH_H
#define FLASH_H

#include "memconfig.h"

/* Common Flash Interface - see www.amd/com/products/nvd/overview/cfi.html */

#define CFI_START_ADDR 0x10
#define CFI_END_ADDR 0x4F

typedef unsigned char (*GetByteCallBack_t)(void);
typedef void (*GetValAtAddrCallBack_t)(unsigned short *vaddr, unsigned short *val);
typedef void (*PutValAtAddrCallBack_t)(unsigned short *vaddr, unsigned short val);

#ifdef BSPCONF_BTLDR_MEMMAP_DEBUG
extern int read_device_codes(unsigned long *Code);
extern int read_cfi_array(unsigned short array[], int array_size);
extern int build_sector_map(unsigned int sector_map[], int sector_map_size);
#endif

extern void flash_read(unsigned int offset,   // Of flash.
                       unsigned short *dest,  // Destination buffer
                       unsigned int num_bytes,
                       PutValAtAddrCallBack_t CBack); // NULL okay

  // --flash_read-- 
  //   Think of the flash part as starting at address
  //   zero (the first read/writable location in the flash
  //   device). The specified dest buffer is filled with flash
  //   data found starting at the specified flash memory range
  //   offset. Unless num_bytes == 0, a minimum of 2 bytes
  //   will always be read into the supplied buffer. If
  //   a CBack is supplied then it will be used to write the
  //   the 16bit flash values, otherwise the supplied *dest
  //   buffers is written to.
  

extern int flash_write(unsigned int offset,    // Of flash.
                        unsigned short *src,    // source buffer.
                        unsigned int num_bytes,
                        GetValAtAddrCallBack_t CBack); // NULL okay

  // --flash_write-- 
  //   The src pointer indicates the start of the data block
  //   which is to be copied to the flash memory range starting
  //   at the specified offset. Note: unless num_bytes == 0, a
  //   minimum of 2 bytes is always written. If a CBack is
  //   supplied then it will be use to acquire each 16bit val
  //   which is to be written to flash, otherwise the supplied
  //   *src buffer is used for the copy.
  //   Returns zero on success and non-zero on flash write failure

extern int flash_flush(void);

  // --flash_flush--
  //   Similiar to the `fflush()` of standard Linux.
  //   Use this after you have completed your set of
  //   flash_write() calls to insure that any internally
  //   buffered data has been written to flash.
  //   returns -1 on success, otherwise returns the flash
  //   offset for which a write error occured.

extern void flash_erase(void);

  // --flash_erase--
  //   Erases the board's entire flash range.

extern void flash_erase_range(int start_addr, int end_addr);

  // --flash_erase_range--
  //   Erases the indicated portion of the flash.
  //   Note: the whole block containing the start_addr as well as
  //   the whole block containing the end_addr, and all blocks
  //   in-between, are erased. Keep this in mind when forming
  //   your range request -- if not careful you will get more
  //   erased than your range defines due to the erase constraints
  //   of flash chips. They can only erase whole blocks.
  //   +--- NOTE! ----
  //   |  *revisit-skranz* This routine is an intermediate solution.
  //   |  How does the client know which addresses fall on which
  //   |  flash blocks without knowing the details of the underlying
  //   |  flash chips used? Unfortunatley, at the moment, they will
  //   |  just have to know. And in fact the areas of the flash map
  //   |  which have been choosen to hold the various components
  //   |  (bootloader, params, kernel, filesystem) have been defined
  //   |  in the comp_flash_info[] array of btldr_pi.c in a way that
  //   |  places them convieniently on flash block boundaries that
  //   |  allow each component to be erased without effecting the
  //   |  surrounding components. There is a coupling here that we
  //   |  hope to remove in the future since ideally the client
  //   |  shouldn't need to know anything about the underlying chips.
  //   +--------------

extern int flash_init(void);

  // --flash_init--
  //   Called once at bootloader init to initialize the module and make
  //   it ready for client use.
  //   +--- NOTE! ----
  //   |  *revisit-skranz* At the moment this function has a return value
  //   |  indicating to the caller the type of chips located on the
  //   |  board so that the client can later make the correct type of
  //   |  calls to the flash_erase_range() routine (see comments above).
  //   |  Again, this exists only as part of the intermediate solution.
  //   |  There is a coupling here that we hope to remove in the future. The
  //   |  client shouldn't need to know anything about the underlying chips.
  //   |  Current valid return values are: 128, 160, 320
  //   +--------------

#endif