sd-card.h revision 199767f8919635c4928607450d9e0abb932109ce
/*-
* Copyright (c) 2006 M. Warner Losh. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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.
*
* This software is derived from software provide by Kwikbyte who specifically
* disclaimed copyright on the code.
*
* $FreeBSD$
*/
#ifndef __SD_CARD_H
#define __SD_CARD_H
/* MCI_read() is the original read function, taking a byte offset and byte
* count. It is preserved to support existing customized boot code that still
* refers to it; it will work fine even on SDHC cards as long as the kernel and
* the metadata for locating it all exist within the first 4GB of the card.
*
* MCI_readblocks() is the new read function, taking offset and length in terms
* of block counts (where the SD spec defines a block as 512 bytes), allowing
* the kernel and filesystem metadata to be located anywhere on an SDHC card.
*
* Returns 0 on success, non-zero on failure.
*/
int MCI_read (char* dest, unsigned bytenum, unsigned length);
int MCI_readblocks (char* dest, unsigned blknum, unsigned blkcount);
/* sdcard_init() - get things set up to read from an SD or SDHC card.
*
* Returns 0 on failure, non-zero on success.
*/
int sdcard_init(void);
/* By default sdcard_init() sets things up for a 1-wire interface to the
* SD card. Calling sdcard_4wire(true) after sdcard_init() allows customized
* boot code to change to 4-bit transfers when the hardware supports it.
*
* Returns 0 on failure, non-zero on success.
*/
int sdcard_use4wire(int use4wire);
#endif