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/*
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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 any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <gpxe/blockdev.h>
#include <gpxe/ramdisk.h>
/**
* @file
*
* RAM disks
*
*/
static inline __attribute__ (( always_inline )) struct ramdisk *
block_to_ramdisk ( struct block_device *blockdev ) {
return container_of ( blockdev, struct ramdisk, blockdev );
}
/**
* Read block
*
* @v blockdev Block device
* @v block Block number
* @v count Block count
* @v buffer Data buffer
* @ret rc Return status code
*/
static int ramdisk_read ( struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
struct ramdisk *ramdisk = block_to_ramdisk ( blockdev );
unsigned long offset = ( block * blockdev->blksize );
unsigned long length = ( count * blockdev->blksize );
DBGC ( ramdisk, "RAMDISK %p reading [%lx,%lx)\n",
ramdisk, offset, length );
memcpy_user ( buffer, 0, ramdisk->data, offset, length );
return 0;
}
/**
* Write block
*
* @v blockdev Block device
* @v block Block number
* @v count Block count
* @v buffer Data buffer
* @ret rc Return status code
*/
static int ramdisk_write ( struct block_device *blockdev, uint64_t block,
unsigned long count, userptr_t buffer ) {
struct ramdisk *ramdisk = block_to_ramdisk ( blockdev );
unsigned long offset = ( block * blockdev->blksize );
unsigned long length = ( count * blockdev->blksize );
DBGC ( ramdisk, "RAMDISK %p writing [%lx,%lx)\n",
ramdisk, offset, length );
memcpy_user ( ramdisk->data, offset, buffer, 0, length );
return 0;
}
int init_ramdisk ( struct ramdisk *ramdisk, userptr_t data, size_t len,
unsigned int blksize ) {
if ( ! blksize )
blksize = 512;
ramdisk->data = data;
ramdisk->blockdev.read = ramdisk_read;
ramdisk->blockdev.write = ramdisk_write;
ramdisk->blockdev.blksize = blksize;
ramdisk->blockdev.blocks = ( len / blksize );
return 0;
}
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