diff options
Diffstat (limited to 'contrib/syslinux-4.02/gpxe/src/drivers/block/ramdisk.c')
-rw-r--r-- | contrib/syslinux-4.02/gpxe/src/drivers/block/ramdisk.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/drivers/block/ramdisk.c b/contrib/syslinux-4.02/gpxe/src/drivers/block/ramdisk.c new file mode 100644 index 0000000..4e6f1bc --- /dev/null +++ b/contrib/syslinux-4.02/gpxe/src/drivers/block/ramdisk.c @@ -0,0 +1,97 @@ +/* + * 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; +} |