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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.
- */
-
- FILE_LICENCE ( GPL2_OR_LATER );
-
- #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;
- }
-
- static struct block_device_operations ramdisk_operations = {
- .read = ramdisk_read,
- .write = ramdisk_write
- };
-
- int init_ramdisk ( struct ramdisk *ramdisk, userptr_t data, size_t len,
- unsigned int blksize ) {
-
- if ( ! blksize )
- blksize = 512;
-
- ramdisk->data = data;
- ramdisk->blockdev.op = &ramdisk_operations;
- ramdisk->blockdev.blksize = blksize;
- ramdisk->blockdev.blocks = ( len / blksize );
-
- return 0;
- }
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