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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.c97
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;
+}