[int13] Refactor to use centralised SAN device abstraction

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 264 insertions, 685 deletions

diff --git a/src/arch/x86/interface/pcbios/int13.c b/src/arch/x86/interface/pcbios/int13.c
index 283e5be7..23cfefca 100644
--- a/src/arch/x86/interface/pcbios/int13.c
+++ b/src/arch/x86/interface/pcbios/int13.c
@@ -29,20 +29,12 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <byteswap.h>
 #include <errno.h>
 #include <assert.h>
-#include <ipxe/list.h>
 #include <ipxe/blockdev.h>
 #include <ipxe/io.h>
-#include <ipxe/open.h>
-#include <ipxe/uri.h>
-#include <ipxe/process.h>
-#include <ipxe/xfer.h>
-#include <ipxe/retry.h>
-#include <ipxe/timer.h>
 #include <ipxe/acpi.h>
 #include <ipxe/sanboot.h>
 #include <ipxe/device.h>
 #include <ipxe/pci.h>
-#include <ipxe/iso9660.h>
 #include <ipxe/eltorito.h>
 #include <realmode.h>
 #include <bios.h>
@@ -59,31 +51,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  *
  */
 
-/**
- * Overall timeout for INT 13 commands (independent of underlying device
- *
- * Underlying devices should ideally never become totally stuck.
- * However, if they do, then the INT 13 mechanism provides no means
- * for the caller to cancel the operation, and the machine appears to
- * hang.  Use an overall timeout for all commands to avoid this
- * problem and bounce timeout failures to the caller.
- */
-#define INT13_COMMAND_TIMEOUT ( 15 * TICKS_PER_SEC )
-
-/** An INT 13 emulated drive */
-struct int13_drive {
-	/** Reference count */
-	struct refcnt refcnt;
-	/** List of all registered drives */
-	struct list_head list;
-
-	/** Block device URI */
-	struct uri *uri;
-	/** Underlying block device interface */
-	struct interface block;
-
-	/** BIOS in-use drive number (0x00-0xff) */
-	unsigned int drive;
+/** INT 13 SAN device private data */
+struct int13_data {
 	/** BIOS natural drive number (0x00-0xff)
 	 *
 	 * This is the drive number that would have been assigned by
@@ -96,16 +65,6 @@ struct int13_drive {
 	 */
 	unsigned int natural_drive;
 
-	/** Block device capacity */
-	struct block_device_capacity capacity;
-	/** INT 13 emulated blocksize shift
-	 *
-	 * To allow for emulation of CD-ROM access, this represents
-	 * the left-shift required to translate from INT 13 blocks to
-	 * underlying blocks.
-	 */
-	unsigned int blksize_shift;
-
 	/** Number of cylinders
 	 *
 	 * The cylinder number field in an INT 13 call is ten bits
@@ -131,13 +90,8 @@ struct int13_drive {
 	 */
 	unsigned int sectors_per_track;
 
-	/** Drive is a CD-ROM */
-	int is_cdrom;
 	/** Address of El Torito boot catalog (if any) */
 	unsigned int boot_catalog;
-
-	/** Underlying device status, if in error */
-	int block_rc;
 	/** Status of last operation */
 	int last_status;
 };
@@ -158,9 +112,6 @@ static struct int13_fdd_parameters __data16 ( int13_fdd_params ) = {
 };
 #define int13_fdd_params __use_data16 ( int13_fdd_params )
 
-/** List of registered emulated drives */
-static LIST_HEAD ( int13s );
-
 /**
  * Equipment word
  *
@@ -189,293 +140,37 @@ static uint8_t __text16 ( num_drives );
 #define num_drives __use_text16 ( num_drives )
 
 /**
- * Calculate INT 13 drive sector size
- *
- * @v int13		Emulated drive
- * @ret blksize		Sector size
- */
-static inline size_t int13_blksize ( struct int13_drive *int13 ) {
-	return ( int13->capacity.blksize << int13->blksize_shift );
-}
-
-/**
- * Calculate INT 13 drive capacity
+ * Calculate SAN device capacity (limited to 32 bits)
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @ret blocks		Number of blocks
  */
-static inline uint64_t int13_capacity ( struct int13_drive *int13 ) {
-	return ( int13->capacity.blocks >> int13->blksize_shift );
-}
-
-/**
- * Calculate INT 13 drive capacity (limited to 32 bits)
- *
- * @v int13		Emulated drive
- * @ret blocks		Number of blocks
- */
-static inline uint32_t int13_capacity32 ( struct int13_drive *int13 ) {
-	uint64_t capacity = int13_capacity ( int13 );
+static inline uint32_t int13_capacity32 ( struct san_device *sandev ) {
+	uint64_t capacity = sandev_capacity ( sandev );
 	return ( ( capacity <= 0xffffffffUL ) ? capacity : 0xffffffff );
 }
 
 /**
- * Test if INT 13 drive is a floppy disk drive
- *
- * @v int13		Emulated drive
- * @ret is_fdd		Emulated drive is a floppy disk
- */
-static inline int int13_is_fdd ( struct int13_drive *int13 ) {
-	return ( ! ( int13->drive & 0x80 ) );
-}
-
-/** An INT 13 command */
-struct int13_command {
-	/** Status */
-	int rc;
-	/** INT 13 drive */
-	struct int13_drive *int13;
-	/** Underlying block device interface */
-	struct interface block;
-	/** Command timeout timer */
-	struct retry_timer timer;
-};
-
-/**
- * Record INT 13 drive capacity
- *
- * @v command		INT 13 command
- * @v capacity		Block device capacity
- */
-static void int13_command_capacity ( struct int13_command *command,
-				     struct block_device_capacity *capacity ) {
-	memcpy ( &command->int13->capacity, capacity,
-		 sizeof ( command->int13->capacity ) );
-}
-
-/**
- * Close INT 13 command
- *
- * @v command		INT 13 command
- * @v rc		Reason for close
- */
-static void int13_command_close ( struct int13_command *command, int rc ) {
-	intf_restart ( &command->block, rc );
-	stop_timer ( &command->timer );
-	command->rc = rc;
-}
-
-/**
- * Handle INT 13 command timer expiry
+ * Test if SAN device is a floppy disk drive
  *
- * @v timer		Timer
+ * @v sandev		SAN device
+ * @ret is_fdd		SAN device is a floppy disk drive
  */
-static void int13_command_expired ( struct retry_timer *timer,
-				    int over __unused ) {
-	struct int13_command *command =
-		container_of ( timer, struct int13_command, timer );
-
-	int13_command_close ( command, -ETIMEDOUT );
+static inline int int13_is_fdd ( struct san_device *sandev ) {
+	return ( ! ( sandev->drive & 0x80 ) );
 }
 
-/** INT 13 command interface operations */
-static struct interface_operation int13_command_op[] = {
-	INTF_OP ( intf_close, struct int13_command *, int13_command_close ),
-	INTF_OP ( block_capacity, struct int13_command *,
-		  int13_command_capacity ),
-};
-
-/** INT 13 command interface descriptor */
-static struct interface_descriptor int13_command_desc =
-	INTF_DESC ( struct int13_command, block, int13_command_op );
-
 /**
- * Open (or reopen) INT 13 emulated drive underlying block device
+ * Parse El Torito parameters
  *
- * @v int13		Emulated drive
- * @ret rc		Return status code
- */
-static int int13_reopen_block ( struct int13_drive *int13 ) {
-	int rc;
-
-	/* Close any existing block device */
-	intf_restart ( &int13->block, -ECONNRESET );
-
-	/* Open block device */
-	if ( ( rc = xfer_open_uri ( &int13->block, int13->uri ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x could not reopen block "
-		       "device: %s\n", int13->drive, strerror ( rc ) );
-		int13->block_rc = rc;
-		return rc;
-	}
-
-	/* Clear block device error status */
-	int13->block_rc = 0;
-
-	return 0;
-}
-
-/**
- * Prepare to issue INT 13 command
- *
- * @v command		INT 13 command
- * @v int13		Emulated drive
- * @ret rc		Return status code
- */
-static int int13_command_start ( struct int13_command *command,
-				 struct int13_drive *int13 ) {
-	int rc;
-
-	/* Sanity check */
-	assert ( command->int13 == NULL );
-	assert ( ! timer_running ( &command->timer ) );
-
-	/* Reopen block device if necessary */
-	if ( ( int13->block_rc != 0 ) &&
-	     ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) )
-		return rc;
-
-	/* Initialise command */
-	command->rc = -EINPROGRESS;
-	command->int13 = int13;
-	start_timer_fixed ( &command->timer, INT13_COMMAND_TIMEOUT );
-
-	/* Wait for block control interface to become ready */
-	while ( ( command->rc == -EINPROGRESS ) &&
-		( xfer_window ( &int13->block ) == 0 ) ) {
-		step();
-	}
-
-	return ( ( command->rc == -EINPROGRESS ) ?
-		 int13->block_rc : command->rc );
-}
-
-/**
- * Wait for INT 13 command to complete
- *
- * @v command		INT 13 command
- * @ret rc		Return status code
- */
-static int int13_command_wait ( struct int13_command *command ) {
-
-	/* Sanity check */
-	assert ( timer_running ( &command->timer ) );
-
-	/* Wait for command to complete */
-	while ( command->rc == -EINPROGRESS )
-		step();
-
-	assert ( ! timer_running ( &command->timer ) );
-	return command->rc;
-}
-
-/**
- * Terminate INT 13 command
- *
- * @v command		INT 13 command
- */
-static void int13_command_stop ( struct int13_command *command ) {
-	stop_timer ( &command->timer );
-	command->int13 = NULL;
-}
-
-/** The single active INT 13 command */
-static struct int13_command int13_command = {
-	.block = INTF_INIT ( int13_command_desc ),
-	.timer = TIMER_INIT ( int13_command_expired ),
-};
-
-/**
- * Read from or write to INT 13 drive
- *
- * @v int13		Emulated drive
- * @v lba		Starting logical block address
- * @v count		Number of logical blocks
- * @v buffer		Data buffer
- * @v block_rw		Block read/write method
- * @ret rc		Return status code
- */
-static int int13_rw ( struct int13_drive *int13, uint64_t lba,
-		      unsigned int count, userptr_t buffer,
-		      int ( * block_rw ) ( struct interface *control,
-					   struct interface *data,
-					   uint64_t lba, unsigned int count,
-					   userptr_t buffer, size_t len ) ) {
-	struct int13_command *command = &int13_command;
-	unsigned int frag_count;
-	size_t frag_len;
-	int rc;
-
-	/* Translate to underlying blocksize */
-	lba <<= int13->blksize_shift;
-	count <<= int13->blksize_shift;
-
-	while ( count ) {
-
-		/* Determine fragment length */
-		frag_count = count;
-		if ( frag_count > int13->capacity.max_count )
-			frag_count = int13->capacity.max_count;
-		frag_len = ( int13->capacity.blksize * frag_count );
-
-		/* Issue command */
-		if ( ( ( rc = int13_command_start ( command, int13 ) ) != 0 ) ||
-		     ( ( rc = block_rw ( &int13->block, &command->block, lba,
-					 frag_count, buffer,
-					 frag_len ) ) != 0 ) ||
-		     ( ( rc = int13_command_wait ( command ) ) != 0 ) ) {
-			int13_command_stop ( command );
-			return rc;
-		}
-		int13_command_stop ( command );
-
-		/* Move to next fragment */
-		lba += frag_count;
-		count -= frag_count;
-		buffer = userptr_add ( buffer, frag_len );
-	}
-
-	return 0;
-}
-
-/**
- * Read INT 13 drive capacity
- *
- * @v int13		Emulated drive
- * @ret rc		Return status code
- */
-static int int13_read_capacity ( struct int13_drive *int13 ) {
-	struct int13_command *command = &int13_command;
-	int rc;
-
-	/* Issue command */
-	if ( ( ( rc = int13_command_start ( command, int13 ) ) != 0 ) ||
-	     ( ( rc = block_read_capacity ( &int13->block,
-					    &command->block ) ) != 0 ) ||
-	     ( ( rc = int13_command_wait ( command ) ) != 0 ) ) {
-		int13_command_stop ( command );
-		return rc;
-	}
-
-	int13_command_stop ( command );
-	return 0;
-}
-
-/**
- * Parse ISO9660 parameters
- *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v scratch		Scratch area for single-sector reads
  * @ret rc		Return status code
  *
- * Reads and parses ISO9660 parameters, if present.
+ * Reads and parses El Torito parameters, if present.
  */
-static int int13_parse_iso9660 ( struct int13_drive *int13, void *scratch ) {
-	static const struct iso9660_primary_descriptor_fixed primary_check = {
-		.type = ISO9660_TYPE_PRIMARY,
-		.id = ISO9660_ID,
-	};
-	struct iso9660_primary_descriptor *primary = scratch;
+static int int13_parse_eltorito ( struct san_device *sandev, void *scratch ) {
+	struct int13_data *int13 = sandev->priv;
 	static const struct eltorito_descriptor_fixed boot_check = {
 		.type = ISO9660_TYPE_BOOT,
 		.id = ISO9660_ID,
@@ -483,69 +178,34 @@ static int int13_parse_iso9660 ( struct int13_drive *int13, void *scratch ) {
 		.system_id = "EL TORITO SPECIFICATION",
 	};
 	struct eltorito_descriptor *boot = scratch;
-	unsigned int blksize;
-	unsigned int blksize_shift;
 	int rc;
 
-	/* Calculate required blocksize shift */
-	blksize = int13_blksize ( int13 );
-	blksize_shift = 0;
-	while ( blksize < ISO9660_BLKSIZE ) {
-		blksize <<= 1;
-		blksize_shift++;
-	}
-	if ( blksize > ISO9660_BLKSIZE ) {
-		/* Do nothing if the blksize is invalid for CD-ROM access */
-		return 0;
-	}
-
-	/* Read primary volume descriptor */
-	if ( ( rc = int13_rw ( int13,
-			       ( ISO9660_PRIMARY_LBA << blksize_shift ), 1,
-			       virt_to_user ( primary ), block_read ) ) != 0 ){
-		DBGC ( int13, "INT13 drive %02x could not read ISO9660 "
-		       "primary volume descriptor: %s\n",
-		       int13->drive, strerror ( rc ) );
-		return rc;
-	}
-
-	/* Do nothing unless this is an ISO image */
-	if ( memcmp ( primary, &primary_check, sizeof ( primary_check ) ) != 0 )
-		return 0;
-	DBGC ( int13, "INT13 drive %02x contains an ISO9660 filesystem; "
-	       "treating as CD-ROM\n", int13->drive );
-	int13->is_cdrom = 1;
-
 	/* Read boot record volume descriptor */
-	if ( ( rc = int13_rw ( int13,
-			       ( ELTORITO_LBA << blksize_shift ), 1,
-			       virt_to_user ( boot ), block_read ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x could not read El Torito boot "
+	if ( ( rc = sandev_rw ( sandev, ELTORITO_LBA, 1,
+				virt_to_user ( boot ), block_read ) ) != 0 ) {
+		DBGC ( sandev, "INT13 drive %02x could not read El Torito boot "
 		       "record volume descriptor: %s\n",
-		       int13->drive, strerror ( rc ) );
+		       sandev->drive, strerror ( rc ) );
 		return rc;
 	}
 
 	/* Check for an El Torito boot catalog */
 	if ( memcmp ( boot, &boot_check, sizeof ( boot_check ) ) == 0 ) {
 		int13->boot_catalog = boot->sector;
-		DBGC ( int13, "INT13 drive %02x has an El Torito boot catalog "
-		       "at LBA %08x\n", int13->drive, int13->boot_catalog );
+		DBGC ( sandev, "INT13 drive %02x has an El Torito boot catalog "
+		       "at LBA %08x\n", sandev->drive, int13->boot_catalog );
 	} else {
-		DBGC ( int13, "INT13 drive %02x has no El Torito boot "
-		       "catalog\n", int13->drive );
+		DBGC ( sandev, "INT13 drive %02x has no El Torito boot "
+		       "catalog\n", sandev->drive );
 	}
 
-	/* Configure drive for no-emulation CD-ROM access */
-	int13->blksize_shift += blksize_shift;
-
 	return 0;
 }
 
 /**
  * Guess INT 13 hard disk drive geometry
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v scratch		Scratch area for single-sector reads
  * @ret heads		Guessed number of heads
  * @ret sectors		Guessed number of sectors per track
@@ -553,7 +213,7 @@ static int int13_parse_iso9660 ( struct int13_drive *int13, void *scratch ) {
  *
  * Guesses the drive geometry by inspecting the partition table.
  */
-static int int13_guess_geometry_hdd ( struct int13_drive *int13, void *scratch,
+static int int13_guess_geometry_hdd ( struct san_device *sandev, void *scratch,
 				      unsigned int *heads,
 				      unsigned int *sectors ) {
 	struct master_boot_record *mbr = scratch;
@@ -568,17 +228,17 @@ static int int13_guess_geometry_hdd ( struct int13_drive *int13, void *scratch,
 	*sectors = 63;
 
 	/* Read partition table */
-	if ( ( rc = int13_rw ( int13, 0, 1, virt_to_user ( mbr ),
-			       block_read ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x could not read "
+	if ( ( rc = sandev_rw ( sandev, 0, 1, virt_to_user ( mbr ),
+				block_read ) ) != 0 ) {
+		DBGC ( sandev, "INT13 drive %02x could not read "
 		       "partition table to guess geometry: %s\n",
-		       int13->drive, strerror ( rc ) );
+		       sandev->drive, strerror ( rc ) );
 		return rc;
 	}
-	DBGC2 ( int13, "INT13 drive %02x has MBR:\n", int13->drive );
-	DBGC2_HDA ( int13, 0, mbr, sizeof ( *mbr ) );
-	DBGC ( int13, "INT13 drive %02x has signature %08x\n",
-	       int13->drive, mbr->signature );
+	DBGC2 ( sandev, "INT13 drive %02x has MBR:\n", sandev->drive );
+	DBGC2_HDA ( sandev, 0, mbr, sizeof ( *mbr ) );
+	DBGC ( sandev, "INT13 drive %02x has signature %08x\n",
+	       sandev->drive, mbr->signature );
 
 	/* Scan through partition table and modify guesses for
 	 * heads and sectors_per_track if we find any used
@@ -592,9 +252,9 @@ static int int13_guess_geometry_hdd ( struct int13_drive *int13, void *scratch,
 			continue;
 		*heads = ( end_head + 1 );
 		*sectors = end_sector;
-		DBGC ( int13, "INT13 drive %02x guessing C/H/S xx/%d/%d based "
+		DBGC ( sandev, "INT13 drive %02x guessing C/H/S xx/%d/%d based "
 		       "on partition %d\n",
-		       int13->drive, *heads, *sectors, ( i + 1 ) );
+		       sandev->drive, *heads, *sectors, ( i + 1 ) );
 	}
 
 	return 0;
@@ -627,17 +287,17 @@ static const struct int13_fdd_geometry int13_fdd_geometries[] = {
 /**
  * Guess INT 13 floppy disk drive geometry
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @ret heads		Guessed number of heads
  * @ret sectors		Guessed number of sectors per track
  * @ret rc		Return status code
  *
  * Guesses the drive geometry by inspecting the disk size.
  */
-static int int13_guess_geometry_fdd ( struct int13_drive *int13,
+static int int13_guess_geometry_fdd ( struct san_device *sandev,
 				      unsigned int *heads,
 				      unsigned int *sectors ) {
-	unsigned int blocks = int13_capacity ( int13 );
+	unsigned int blocks = sandev_capacity ( sandev );
 	const struct int13_fdd_geometry *geometry;
 	unsigned int cylinders;
 	unsigned int i;
@@ -650,8 +310,8 @@ static int int13_guess_geometry_fdd ( struct int13_drive *int13,
 		*heads = INT13_FDD_HEADS ( geometry );
 		*sectors = INT13_FDD_SECTORS ( geometry );
 		if ( ( cylinders * (*heads) * (*sectors) ) == blocks ) {
-			DBGC ( int13, "INT13 drive %02x guessing C/H/S "
-			       "%d/%d/%d based on size %dK\n", int13->drive,
+			DBGC ( sandev, "INT13 drive %02x guessing C/H/S "
+			       "%d/%d/%d based on size %dK\n", sandev->drive,
 			       cylinders, *heads, *sectors, ( blocks / 2 ) );
 			return 0;
 		}
@@ -662,36 +322,33 @@ static int int13_guess_geometry_fdd ( struct int13_drive *int13,
 	 */
 	*heads = 2;
 	*sectors = 18;
-	DBGC ( int13, "INT13 drive %02x guessing C/H/S xx/%d/%d based on size "
-	       "%dK\n", int13->drive, *heads, *sectors, ( blocks / 2 ) );
+	DBGC ( sandev, "INT13 drive %02x guessing C/H/S xx/%d/%d based on size "
+	       "%dK\n", sandev->drive, *heads, *sectors, ( blocks / 2 ) );
 	return 0;
 }
 
 /**
  * Guess INT 13 drive geometry
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v scratch		Scratch area for single-sector reads
  * @ret rc		Return status code
  */
-static int int13_guess_geometry ( struct int13_drive *int13, void *scratch ) {
+static int int13_guess_geometry ( struct san_device *sandev, void *scratch ) {
+	struct int13_data *int13 = sandev->priv;
 	unsigned int guessed_heads;
 	unsigned int guessed_sectors;
 	unsigned int blocks;
 	unsigned int blocks_per_cyl;
 	int rc;
 
-	/* Don't even try when the blksize is invalid for C/H/S access */
-	if ( int13_blksize ( int13 ) != INT13_BLKSIZE )
-		return 0;
-
 	/* Guess geometry according to drive type */
-	if ( int13_is_fdd ( int13 ) ) {
-		if ( ( rc = int13_guess_geometry_fdd ( int13, &guessed_heads,
+	if ( int13_is_fdd ( sandev ) ) {
+		if ( ( rc = int13_guess_geometry_fdd ( sandev, &guessed_heads,
 						       &guessed_sectors )) != 0)
 			return rc;
 	} else {
-		if ( ( rc = int13_guess_geometry_hdd ( int13, scratch,
+		if ( ( rc = int13_guess_geometry_hdd ( sandev, scratch,
 						       &guessed_heads,
 						       &guessed_sectors )) != 0)
 			return rc;
@@ -704,7 +361,7 @@ static int int13_guess_geometry ( struct int13_drive *int13, void *scratch ) {
 		int13->sectors_per_track = guessed_sectors;
 	if ( ! int13->cylinders ) {
 		/* Avoid attempting a 64-bit divide on a 32-bit system */
-		blocks = int13_capacity32 ( int13 );
+		blocks = int13_capacity32 ( sandev );
 		blocks_per_cyl = ( int13->heads * int13->sectors_per_track );
 		assert ( blocks_per_cyl != 0 );
 		int13->cylinders = ( blocks / blocks_per_cyl );
@@ -719,7 +376,8 @@ static int int13_guess_geometry ( struct int13_drive *int13, void *scratch ) {
  * Update BIOS drive count
  */
 static void int13_sync_num_drives ( void ) {
-	struct int13_drive *int13;
+	struct san_device *sandev;
+	struct int13_data *int13;
 	uint8_t *counter;
 	uint8_t max_drive;
 	uint8_t required;
@@ -730,18 +388,19 @@ static void int13_sync_num_drives ( void ) {
 	num_fdds = ( ( equipment_word & 0x0001 ) ?
 		     ( ( ( equipment_word >> 6 ) & 0x3 ) + 1 ) : 0 );
 
-	/* Ensure count is large enough to cover all of our emulated drives */
-	list_for_each_entry ( int13, &int13s, list ) {
-		counter = ( int13_is_fdd ( int13 ) ? &num_fdds : &num_drives );
-		max_drive = int13->drive;
+	/* Ensure count is large enough to cover all of our SAN devices */
+	for_each_sandev ( sandev ) {
+		int13 = sandev->priv;
+		counter = ( int13_is_fdd ( sandev ) ? &num_fdds : &num_drives );
+		max_drive = sandev->drive;
 		if ( max_drive < int13->natural_drive )
 			max_drive = int13->natural_drive;
 		required = ( ( max_drive & 0x7f ) + 1 );
 		if ( *counter < required ) {
 			*counter = required;
-			DBGC ( int13, "INT13 drive %02x added to drive count: "
+			DBGC ( sandev, "INT13 drive %02x added to drive count: "
 			       "%d HDDs, %d FDDs\n",
-			       int13->drive, num_drives, num_fdds );
+			       sandev->drive, num_drives, num_fdds );
 		}
 	}
 
@@ -773,21 +432,17 @@ static void int13_check_num_drives ( void ) {
 /**
  * INT 13, 00 - Reset disk system
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @ret status		Status code
  */
-static int int13_reset ( struct int13_drive *int13,
+static int int13_reset ( struct san_device *sandev,
 			 struct i386_all_regs *ix86 __unused ) {
 	int rc;
 
-	DBGC2 ( int13, "Reset drive\n" );
-
-	/* Reopen underlying block device */
-	if ( ( rc = int13_reopen_block ( int13 ) ) != 0 )
-		return -INT13_STATUS_RESET_FAILED;
+	DBGC2 ( sandev, "Reset drive\n" );
 
-	/* Check that block device is functional */
-	if ( ( rc = int13_read_capacity ( int13 ) ) != 0 )
+	/* Reset SAN device */
+	if ( ( rc = sandev_reset ( sandev ) ) != 0 )
 		return -INT13_STATUS_RESET_FAILED;
 
 	return 0;
@@ -796,19 +451,21 @@ static int int13_reset ( struct int13_drive *int13,
 /**
  * INT 13, 01 - Get status of last operation
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @ret status		Status code
  */
-static int int13_get_last_status ( struct int13_drive *int13,
+static int int13_get_last_status ( struct san_device *sandev,
 				   struct i386_all_regs *ix86 __unused ) {
-	DBGC2 ( int13, "Get status of last operation\n" );
+	struct int13_data *int13 = sandev->priv;
+
+	DBGC2 ( sandev, "Get status of last operation\n" );
 	return int13->last_status;
 }
 
 /**
  * Read / write sectors
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v al		Number of sectors to read or write (must be nonzero)
  * @v ch		Low bits of cylinder number
  * @v cl (bits 7:6)	High bits of cylinder number
@@ -819,7 +476,7 @@ static int int13_get_last_status ( struct int13_drive *int13,
  * @ret status		Status code
  * @ret al		Number of sectors read or written
  */
-static int int13_rw_sectors ( struct int13_drive *int13,
+static int int13_rw_sectors ( struct san_device *sandev,
 			      struct i386_all_regs *ix86,
 			      int ( * block_rw ) ( struct interface *control,
 						   struct interface *data,
@@ -827,6 +484,7 @@ static int int13_rw_sectors ( struct int13_drive *int13,
 						   unsigned int count,
 						   userptr_t buffer,
 						   size_t len ) ) {
+	struct int13_data *int13 = sandev->priv;
 	unsigned int cylinder, head, sector;
 	unsigned long lba;
 	unsigned int count;
@@ -834,10 +492,10 @@ static int int13_rw_sectors ( struct int13_drive *int13,
 	int rc;
 
 	/* Validate blocksize */
-	if ( int13_blksize ( int13 ) != INT13_BLKSIZE ) {
-		DBGC ( int13, "\nINT 13 drive %02x invalid blocksize (%zd) "
+	if ( sandev_blksize ( sandev ) != INT13_BLKSIZE ) {
+		DBGC ( sandev, "\nINT 13 drive %02x invalid blocksize (%zd) "
 		       "for non-extended read/write\n",
-		       int13->drive, int13_blksize ( int13 ) );
+		       sandev->drive, sandev_blksize ( sandev ) );
 		return -INT13_STATUS_INVALID;
 	}
 
@@ -848,7 +506,7 @@ static int int13_rw_sectors ( struct int13_drive *int13,
 	if ( ( cylinder >= int13->cylinders ) ||
 	     ( head >= int13->heads ) ||
 	     ( sector < 1 ) || ( sector > int13->sectors_per_track ) ) {
-		DBGC ( int13, "C/H/S %d/%d/%d out of range for geometry "
+		DBGC ( sandev, "C/H/S %d/%d/%d out of range for geometry "
 		       "%d/%d/%d\n", cylinder, head, sector, int13->cylinders,
 		       int13->heads, int13->sectors_per_track );
 		return -INT13_STATUS_INVALID;
@@ -858,14 +516,14 @@ static int int13_rw_sectors ( struct int13_drive *int13,
 	count = ix86->regs.al;
 	buffer = real_to_user ( ix86->segs.es, ix86->regs.bx );
 
-	DBGC2 ( int13, "C/H/S %d/%d/%d = LBA %08lx <-> %04x:%04x (count %d)\n",
+	DBGC2 ( sandev, "C/H/S %d/%d/%d = LBA %08lx <-> %04x:%04x (count %d)\n",
 		cylinder, head, sector, lba, ix86->segs.es, ix86->regs.bx,
 		count );
 
 	/* Read from / write to block device */
-	if ( ( rc = int13_rw ( int13, lba, count, buffer, block_rw ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x I/O failed: %s\n",
-		       int13->drive, strerror ( rc ) );
+	if ( ( rc = sandev_rw ( sandev, lba, count, buffer, block_rw ) ) != 0 ){
+		DBGC ( sandev, "INT13 drive %02x I/O failed: %s\n",
+		       sandev->drive, strerror ( rc ) );
 		return -INT13_STATUS_READ_ERROR;
 	}
 
@@ -875,7 +533,7 @@ static int int13_rw_sectors ( struct int13_drive *int13,
 /**
  * INT 13, 02 - Read sectors
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v al		Number of sectors to read (must be nonzero)
  * @v ch		Low bits of cylinder number
  * @v cl (bits 7:6)	High bits of cylinder number
@@ -885,16 +543,17 @@ static int int13_rw_sectors ( struct int13_drive *int13,
  * @ret status		Status code
  * @ret al		Number of sectors read
  */
-static int int13_read_sectors ( struct int13_drive *int13,
+static int int13_read_sectors ( struct san_device *sandev,
 				struct i386_all_regs *ix86 ) {
-	DBGC2 ( int13, "Read: " );
-	return int13_rw_sectors ( int13, ix86, block_read );
+
+	DBGC2 ( sandev, "Read: " );
+	return int13_rw_sectors ( sandev, ix86, block_read );
 }
 
 /**
  * INT 13, 03 - Write sectors
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v al		Number of sectors to write (must be nonzero)
  * @v ch		Low bits of cylinder number
  * @v cl (bits 7:6)	High bits of cylinder number
@@ -904,16 +563,17 @@ static int int13_read_sectors ( struct int13_drive *int13,
  * @ret status		Status code
  * @ret al		Number of sectors written
  */
-static int int13_write_sectors ( struct int13_drive *int13,
+static int int13_write_sectors ( struct san_device *sandev,
 				 struct i386_all_regs *ix86 ) {
-	DBGC2 ( int13, "Write: " );
-	return int13_rw_sectors ( int13, ix86, block_write );
+
+	DBGC2 ( sandev, "Write: " );
+	return int13_rw_sectors ( sandev, ix86, block_write );
 }
 
 /**
  * INT 13, 08 - Get drive parameters
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @ret status		Status code
  * @ret ch		Low bits of maximum cylinder number
  * @ret cl (bits 7:6)	High bits of maximum cylinder number
@@ -921,19 +581,20 @@ static int int13_write_sectors ( struct int13_drive *int13,
  * @ret dh		Maximum head number
  * @ret dl		Number of drives
  */
-static int int13_get_parameters ( struct int13_drive *int13,
+static int int13_get_parameters ( struct san_device *sandev,
 				  struct i386_all_regs *ix86 ) {
+	struct int13_data *int13 = sandev->priv;
 	unsigned int max_cylinder = int13->cylinders - 1;
 	unsigned int max_head = int13->heads - 1;
 	unsigned int max_sector = int13->sectors_per_track; /* sic */
 
-	DBGC2 ( int13, "Get drive parameters\n" );
+	DBGC2 ( sandev, "Get drive parameters\n" );
 
 	/* Validate blocksize */
-	if ( int13_blksize ( int13 ) != INT13_BLKSIZE ) {
-		DBGC ( int13, "\nINT 13 drive %02x invalid blocksize (%zd) "
+	if ( sandev_blksize ( sandev ) != INT13_BLKSIZE ) {
+		DBGC ( sandev, "\nINT 13 drive %02x invalid blocksize (%zd) "
 		       "for non-extended parameters\n",
-		       int13->drive, int13_blksize ( int13 ) );
+		       sandev->drive, sandev_blksize ( sandev ) );
 		return -INT13_STATUS_INVALID;
 	}
 
@@ -941,10 +602,10 @@ static int int13_get_parameters ( struct int13_drive *int13,
 	ix86->regs.ch = ( max_cylinder & 0xff );
 	ix86->regs.cl = ( ( ( max_cylinder >> 8 ) << 6 ) | max_sector );
 	ix86->regs.dh = max_head;
-	ix86->regs.dl = ( int13_is_fdd ( int13 ) ? num_fdds : num_drives );
+	ix86->regs.dl = ( int13_is_fdd ( sandev ) ? num_fdds : num_drives );
 
 	/* Floppy-specific parameters */
-	if ( int13_is_fdd ( int13 ) ) {
+	if ( int13_is_fdd ( sandev ) ) {
 		ix86->regs.bl = INT13_FDD_TYPE_1M44;
 		ix86->segs.es = rm_ds;
 		ix86->regs.di = __from_data16 ( &int13_fdd_params );
@@ -956,21 +617,21 @@ static int int13_get_parameters ( struct int13_drive *int13,
 /**
  * INT 13, 15 - Get disk type
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @ret ah		Type code
  * @ret cx:dx		Sector count
  * @ret status		Status code / disk type
  */
-static int int13_get_disk_type ( struct int13_drive *int13,
+static int int13_get_disk_type ( struct san_device *sandev,
 				 struct i386_all_regs *ix86 ) {
 	uint32_t blocks;
 
-	DBGC2 ( int13, "Get disk type\n" );
+	DBGC2 ( sandev, "Get disk type\n" );
 
-	if ( int13_is_fdd ( int13 ) ) {
+	if ( int13_is_fdd ( sandev ) ) {
 		return INT13_DISK_TYPE_FDD;
 	} else {
-		blocks = int13_capacity32 ( int13 );
+		blocks = int13_capacity32 ( sandev );
 		ix86->regs.cx = ( blocks >> 16 );
 		ix86->regs.dx = ( blocks & 0xffff );
 		return INT13_DISK_TYPE_HDD;
@@ -980,16 +641,17 @@ static int int13_get_disk_type ( struct int13_drive *int13,
 /**
  * INT 13, 41 - Extensions installation check
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v bx		0x55aa
  * @ret bx		0xaa55
  * @ret cx		Extensions API support bitmap
  * @ret status		Status code / API version
  */
-static int int13_extension_check ( struct int13_drive *int13 __unused,
+static int int13_extension_check ( struct san_device *sandev __unused,
 				   struct i386_all_regs *ix86 ) {
+
 	if ( ix86->regs.bx == 0x55aa ) {
-		DBGC2 ( int13, "INT13 extensions installation check\n" );
+		DBGC2 ( sandev, "INT13 extensions installation check\n" );
 		ix86->regs.bx = 0xaa55;
 		ix86->regs.cx = ( INT13_EXTENSION_LINEAR |
 				  INT13_EXTENSION_EDD |
@@ -1003,12 +665,12 @@ static int int13_extension_check ( struct int13_drive *int13 __unused,
 /**
  * Extended read / write
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v ds:si		Disk address packet
  * @v block_rw		Block read/write method
  * @ret status		Status code
  */
-static int int13_extended_rw ( struct int13_drive *int13,
+static int int13_extended_rw ( struct san_device *sandev,
 			       struct i386_all_regs *ix86,
 			       int ( * block_rw ) ( struct interface *control,
 						    struct interface *data,
@@ -1027,14 +689,14 @@ static int int13_extended_rw ( struct int13_drive *int13,
 	 * ELTORITO.SYS seems to assume that we are really a CD-ROM if
 	 * we support extended reads for a floppy drive.
 	 */
-	if ( int13_is_fdd ( int13 ) )
+	if ( int13_is_fdd ( sandev ) )
 		return -INT13_STATUS_INVALID;
 
 	/* Get buffer size */
 	get_real ( bufsize, ix86->segs.ds,
 		   ( ix86->regs.si + offsetof ( typeof ( addr ), bufsize ) ) );
 	if ( bufsize < offsetof ( typeof ( addr ), buffer_phys ) ) {
-		DBGC2 ( int13, "<invalid buffer size %#02x\n>\n", bufsize );
+		DBGC2 ( sandev, "<invalid buffer size %#02x\n>\n", bufsize );
 		return -INT13_STATUS_INVALID;
 	}
 
@@ -1042,17 +704,17 @@ static int int13_extended_rw ( struct int13_drive *int13,
 	memset ( &addr, 0, sizeof ( addr ) );
 	copy_from_real ( &addr, ix86->segs.ds, ix86->regs.si, bufsize );
 	lba = addr.lba;
-	DBGC2 ( int13, "LBA %08llx <-> ", ( ( unsigned long long ) lba ) );
+	DBGC2 ( sandev, "LBA %08llx <-> ", ( ( unsigned long long ) lba ) );
 	if ( ( addr.count == 0xff ) ||
 	     ( ( addr.buffer.segment == 0xffff ) &&
 	       ( addr.buffer.offset == 0xffff ) ) ) {
 		buffer = phys_to_user ( addr.buffer_phys );
-		DBGC2 ( int13, "%08llx",
+		DBGC2 ( sandev, "%08llx",
 			( ( unsigned long long ) addr.buffer_phys ) );
 	} else {
 		buffer = real_to_user ( addr.buffer.segment,
 					addr.buffer.offset );
-		DBGC2 ( int13, "%04x:%04x", addr.buffer.segment,
+		DBGC2 ( sandev, "%04x:%04x", addr.buffer.segment,
 			addr.buffer.offset );
 	}
 	if ( addr.count <= 0x7f ) {
@@ -1060,15 +722,15 @@ static int int13_extended_rw ( struct int13_drive *int13,
 	} else if ( addr.count == 0xff ) {
 		count = addr.long_count;
 	} else {
-		DBGC2 ( int13, " <invalid count %#02x>\n", addr.count );
+		DBGC2 ( sandev, " <invalid count %#02x>\n", addr.count );
 		return -INT13_STATUS_INVALID;
 	}
-	DBGC2 ( int13, " (count %ld)\n", count );
+	DBGC2 ( sandev, " (count %ld)\n", count );
 
 	/* Read from / write to block device */
-	if ( ( rc = int13_rw ( int13, lba, count, buffer, block_rw ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x extended I/O failed: %s\n",
-		       int13->drive, strerror ( rc ) );
+	if ( ( rc = sandev_rw ( sandev, lba, count, buffer, block_rw ) ) != 0 ){
+		DBGC ( sandev, "INT13 drive %02x extended I/O failed: %s\n",
+		       sandev->drive, strerror ( rc ) );
 		/* Record that no blocks were transferred successfully */
 		addr.count = 0;
 		put_real ( addr.count, ix86->segs.ds,
@@ -1083,37 +745,39 @@ static int int13_extended_rw ( struct int13_drive *int13,
 /**
  * INT 13, 42 - Extended read
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v ds:si		Disk address packet
  * @ret status		Status code
  */
-static int int13_extended_read ( struct int13_drive *int13,
+static int int13_extended_read ( struct san_device *sandev,
 				 struct i386_all_regs *ix86 ) {
-	DBGC2 ( int13, "Extended read: " );
-	return int13_extended_rw ( int13, ix86, block_read );
+
+	DBGC2 ( sandev, "Extended read: " );
+	return int13_extended_rw ( sandev, ix86, block_read );
 }
 
 /**
  * INT 13, 43 - Extended write
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v ds:si		Disk address packet
  * @ret status		Status code
  */
-static int int13_extended_write ( struct int13_drive *int13,
+static int int13_extended_write ( struct san_device *sandev,
 				  struct i386_all_regs *ix86 ) {
-	DBGC2 ( int13, "Extended write: " );
-	return int13_extended_rw ( int13, ix86, block_write );
+
+	DBGC2 ( sandev, "Extended write: " );
+	return int13_extended_rw ( sandev, ix86, block_write );
 }
 
 /**
  * INT 13, 44 - Verify sectors
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v ds:si		Disk address packet
  * @ret status		Status code
  */
-static int int13_extended_verify ( struct int13_drive *int13,
+static int int13_extended_verify ( struct san_device *sandev,
 				   struct i386_all_regs *ix86 ) {
 	struct int13_disk_address addr;
 	uint64_t lba;
@@ -1125,7 +789,7 @@ static int int13_extended_verify ( struct int13_drive *int13,
 				 sizeof ( addr ));
 		lba = addr.lba;
 		count = addr.count;
-		DBGC2 ( int13, "Verify: LBA %08llx (count %ld)\n",
+		DBGC2 ( sandev, "Verify: LBA %08llx (count %ld)\n",
 			( ( unsigned long long ) lba ), count );
 	}
 
@@ -1136,11 +800,11 @@ static int int13_extended_verify ( struct int13_drive *int13,
 /**
  * INT 13, 44 - Extended seek
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v ds:si		Disk address packet
  * @ret status		Status code
  */
-static int int13_extended_seek ( struct int13_drive *int13,
+static int int13_extended_seek ( struct san_device *sandev,
 				 struct i386_all_regs *ix86 ) {
 	struct int13_disk_address addr;
 	uint64_t lba;
@@ -1152,7 +816,7 @@ static int int13_extended_seek ( struct int13_drive *int13,
 				 sizeof ( addr ));
 		lba = addr.lba;
 		count = addr.count;
-		DBGC2 ( int13, "Seek: LBA %08llx (count %ld)\n",
+		DBGC2 ( sandev, "Seek: LBA %08llx (count %ld)\n",
 			( ( unsigned long long ) lba ), count );
 	}
 
@@ -1163,11 +827,11 @@ static int int13_extended_seek ( struct int13_drive *int13,
 /**
  * Build device path information
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v dpi		Device path information
  * @ret rc		Return status code
  */
-static int int13_device_path_info ( struct int13_drive *int13,
+static int int13_device_path_info ( struct san_device *sandev,
 				    struct edd_device_path_information *dpi ) {
 	struct device *device;
 	struct device_description *desc;
@@ -1176,15 +840,15 @@ static int int13_device_path_info ( struct int13_drive *int13,
 	int rc;
 
 	/* Reopen block device if necessary */
-	if ( ( int13->block_rc != 0 ) &&
-	     ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) )
+	if ( sandev_needs_reopen ( sandev ) &&
+	     ( ( rc = sandev_reopen ( sandev ) ) != 0 ) )
 		return rc;
 
 	/* Get underlying hardware device */
-	device = identify_device ( &int13->block );
+	device = identify_device ( &sandev->block );
 	if ( ! device ) {
-		DBGC ( int13, "INT13 drive %02x cannot identify hardware "
-		       "device\n", int13->drive );
+		DBGC ( sandev, "INT13 drive %02x cannot identify hardware "
+		       "device\n", sandev->drive );
 		return -ENODEV;
 	}
 
@@ -1199,16 +863,16 @@ static int int13_device_path_info ( struct int13_drive *int13,
 		dpi->interface_path.pci.channel = 0xff; /* unused */
 		break;
 	default:
-		DBGC ( int13, "INT13 drive %02x unrecognised bus type %d\n",
-		       int13->drive, desc->bus_type );
+		DBGC ( sandev, "INT13 drive %02x unrecognised bus type %d\n",
+		       sandev->drive, desc->bus_type );
 		return -ENOTSUP;
 	}
 
 	/* Get EDD block device description */
-	if ( ( rc = edd_describe ( &int13->block, &dpi->interface_type,
+	if ( ( rc = edd_describe ( &sandev->block, &dpi->interface_type,
 				   &dpi->device_path ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x cannot identify block device: "
-		       "%s\n", int13->drive, strerror ( rc ) );
+		DBGC ( sandev, "INT13 drive %02x cannot identify block device: "
+		       "%s\n", sandev->drive, strerror ( rc ) );
 		return rc;
 	}
 
@@ -1225,12 +889,13 @@ static int int13_device_path_info ( struct int13_drive *int13,
 /**
  * INT 13, 48 - Get extended parameters
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v ds:si		Drive parameter table
  * @ret status		Status code
  */
-static int int13_get_extended_parameters ( struct int13_drive *int13,
+static int int13_get_extended_parameters ( struct san_device *sandev,
 					   struct i386_all_regs *ix86 ) {
+	struct int13_data *int13 = sandev->priv;
 	struct int13_disk_parameters params;
 	struct segoff address;
 	size_t len = sizeof ( params );
@@ -1241,26 +906,26 @@ static int int13_get_extended_parameters ( struct int13_drive *int13,
 	get_real ( bufsize, ix86->segs.ds,
 		   ( ix86->regs.si + offsetof ( typeof ( params ), bufsize )));
 
-	DBGC2 ( int13, "Get extended drive parameters to %04x:%04x+%02x\n",
+	DBGC2 ( sandev, "Get extended drive parameters to %04x:%04x+%02x\n",
 		ix86->segs.ds, ix86->regs.si, bufsize );
 
 	/* Build drive parameters */
 	memset ( &params, 0, sizeof ( params ) );
 	params.flags = INT13_FL_DMA_TRANSPARENT;
 	if ( ( int13->cylinders < 1024 ) &&
-	     ( int13_capacity ( int13 ) <= INT13_MAX_CHS_SECTORS ) ) {
+	     ( sandev_capacity ( sandev ) <= INT13_MAX_CHS_SECTORS ) ) {
 		params.flags |= INT13_FL_CHS_VALID;
 	}
 	params.cylinders = int13->cylinders;
 	params.heads = int13->heads;
 	params.sectors_per_track = int13->sectors_per_track;
-	params.sectors = int13_capacity ( int13 );
-	params.sector_size = int13_blksize ( int13 );
+	params.sectors = sandev_capacity ( sandev );
+	params.sector_size = sandev_blksize ( sandev );
 	memset ( &params.dpte, 0xff, sizeof ( params.dpte ) );
-	if ( ( rc = int13_device_path_info ( int13, &params.dpi ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x could not provide device "
+	if ( ( rc = int13_device_path_info ( sandev, &params.dpi ) ) != 0 ) {
+		DBGC ( sandev, "INT13 drive %02x could not provide device "
 		       "path information: %s\n",
-		       int13->drive, strerror ( rc ) );
+		       sandev->drive, strerror ( rc ) );
 		len = offsetof ( typeof ( params ), dpi );
 	}
 
@@ -1276,11 +941,11 @@ static int int13_get_extended_parameters ( struct int13_drive *int13,
 		params.bufsize = offsetof ( typeof ( params ), dpi );
 	}
 
-	DBGC ( int13, "INT 13 drive %02x described using extended "
-	       "parameters:\n", int13->drive );
+	DBGC ( sandev, "INT 13 drive %02x described using extended "
+	       "parameters:\n", sandev->drive );
 	address.segment = ix86->segs.ds;
 	address.offset = ix86->regs.si;
-	DBGC_HDA ( int13, address, &params, len );
+	DBGC_HDA ( sandev, address, &params, len );
 
 	/* Return drive parameters */
 	if ( len > bufsize )
@@ -1293,29 +958,29 @@ static int int13_get_extended_parameters ( struct int13_drive *int13,
 /**
  * INT 13, 4b - Get status or terminate CD-ROM emulation
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v ds:si		Specification packet
  * @ret status		Status code
  */
-static int int13_cdrom_status_terminate ( struct int13_drive *int13,
+static int int13_cdrom_status_terminate ( struct san_device *sandev,
 					  struct i386_all_regs *ix86 ) {
 	struct int13_cdrom_specification specification;
 
-	DBGC2 ( int13, "Get CD-ROM emulation status to %04x:%04x%s\n",
+	DBGC2 ( sandev, "Get CD-ROM emulation status to %04x:%04x%s\n",
 		ix86->segs.ds, ix86->regs.si,
 		( ix86->regs.al ? "" : " and terminate" ) );
 
 	/* Fail if we are not a CD-ROM */
-	if ( ! int13->is_cdrom ) {
-		DBGC ( int13, "INT13 drive %02x is not a CD-ROM\n",
-		       int13->drive );
+	if ( ! sandev->is_cdrom ) {
+		DBGC ( sandev, "INT13 drive %02x is not a CD-ROM\n",
+		       sandev->drive );
 		return -INT13_STATUS_INVALID;
 	}
 
 	/* Build specification packet */
 	memset ( &specification, 0, sizeof ( specification ) );
 	specification.size = sizeof ( specification );
-	specification.drive = int13->drive;
+	specification.drive = sandev->drive;
 
 	/* Return specification packet */
 	copy_to_real ( ix86->segs.ds, ix86->regs.si, &specification,
@@ -1328,33 +993,34 @@ static int int13_cdrom_status_terminate ( struct int13_drive *int13,
 /**
  * INT 13, 4d - Read CD-ROM boot catalog
  *
- * @v int13		Emulated drive
+ * @v sandev		SAN device
  * @v ds:si		Command packet
  * @ret status		Status code
  */
-static int int13_cdrom_read_boot_catalog ( struct int13_drive *int13,
+static int int13_cdrom_read_boot_catalog ( struct san_device *sandev,
 					   struct i386_all_regs *ix86 ) {
+	struct int13_data *int13 = sandev->priv;
 	struct int13_cdrom_boot_catalog_command command;
 	int rc;
 
 	/* Read parameters from command packet */
 	copy_from_real ( &command, ix86->segs.ds, ix86->regs.si,
 			 sizeof ( command ) );
-	DBGC2 ( int13, "Read CD-ROM boot catalog to %08x\n", command.buffer );
+	DBGC2 ( sandev, "Read CD-ROM boot catalog to %08x\n", command.buffer );
 
 	/* Fail if we have no boot catalog */
 	if ( ! int13->boot_catalog ) {
-		DBGC ( int13, "INT13 drive %02x has no boot catalog\n",
-		       int13->drive );
+		DBGC ( sandev, "INT13 drive %02x has no boot catalog\n",
+		       sandev->drive );
 		return -INT13_STATUS_INVALID;
 	}
 
 	/* Read from boot catalog */
-	if ( ( rc = int13_rw ( int13, ( int13->boot_catalog + command.start ),
-			       command.count, phys_to_user ( command.buffer ),
-			       block_read ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x could not read boot catalog: "
-		       "%s\n", int13->drive, strerror ( rc ) );
+	if ( ( rc = sandev_rw ( sandev, ( int13->boot_catalog + command.start ),
+				command.count, phys_to_user ( command.buffer ),
+				block_read ) ) != 0 ) {
+		DBGC ( sandev, "INT13 drive %02x could not read boot catalog: "
+		       "%s\n", sandev->drive, strerror ( rc ) );
 		return -INT13_STATUS_READ_ERROR;
 	}
 
@@ -1368,79 +1034,81 @@ static int int13_cdrom_read_boot_catalog ( struct int13_drive *int13,
 static __asmcall void int13 ( struct i386_all_regs *ix86 ) {
 	int command = ix86->regs.ah;
 	unsigned int bios_drive = ix86->regs.dl;
-	struct int13_drive *int13;
+	struct san_device *sandev;
+	struct int13_data *int13;
 	int status;
 
 	/* Check BIOS hasn't killed off our drive */
 	int13_check_num_drives();
 
-	list_for_each_entry ( int13, &int13s, list ) {
+	for_each_sandev ( sandev ) {
 
-		if ( bios_drive != int13->drive ) {
+		int13 = sandev->priv;
+		if ( bios_drive != sandev->drive ) {
 			/* Remap any accesses to this drive's natural number */
 			if ( bios_drive == int13->natural_drive ) {
-				DBGC2 ( int13, "INT13,%02x (%02x) remapped to "
+				DBGC2 ( sandev, "INT13,%02x (%02x) remapped to "
 					"(%02x)\n", ix86->regs.ah,
-					bios_drive, int13->drive );
-				ix86->regs.dl = int13->drive;
+					bios_drive, sandev->drive );
+				ix86->regs.dl = sandev->drive;
 				return;
 			} else if ( ( ( bios_drive & 0x7f ) == 0x7f ) &&
 				    ( command == INT13_CDROM_STATUS_TERMINATE )
-				    && int13->is_cdrom ) {
+				    && sandev->is_cdrom ) {
 				/* Catch non-drive-specific CD-ROM calls */
 			} else {
 				continue;
 			}
 		}
 		
-		DBGC2 ( int13, "INT13,%02x (%02x): ",
+		DBGC2 ( sandev, "INT13,%02x (%02x): ",
 			ix86->regs.ah, bios_drive );
 
 		switch ( command ) {
 		case INT13_RESET:
-			status = int13_reset ( int13, ix86 );
+			status = int13_reset ( sandev, ix86 );
 			break;
 		case INT13_GET_LAST_STATUS:
-			status = int13_get_last_status ( int13, ix86 );
+			status = int13_get_last_status ( sandev, ix86 );
 			break;
 		case INT13_READ_SECTORS:
-			status = int13_read_sectors ( int13, ix86 );
+			status = int13_read_sectors ( sandev, ix86 );
 			break;
 		case INT13_WRITE_SECTORS:
-			status = int13_write_sectors ( int13, ix86 );
+			status = int13_write_sectors ( sandev, ix86 );
 			break;
 		case INT13_GET_PARAMETERS:
-			status = int13_get_parameters ( int13, ix86 );
+			status = int13_get_parameters ( sandev, ix86 );
 			break;
 		case INT13_GET_DISK_TYPE:
-			status = int13_get_disk_type ( int13, ix86 );
+			status = int13_get_disk_type ( sandev, ix86 );
 			break;
 		case INT13_EXTENSION_CHECK:
-			status = int13_extension_check ( int13, ix86 );
+			status = int13_extension_check ( sandev, ix86 );
 			break;
 		case INT13_EXTENDED_READ:
-			status = int13_extended_read ( int13, ix86 );
+			status = int13_extended_read ( sandev, ix86 );
 			break;
 		case INT13_EXTENDED_WRITE:
-			status = int13_extended_write ( int13, ix86 );
+			status = int13_extended_write ( sandev, ix86 );
 			break;
 		case INT13_EXTENDED_VERIFY:
-			status = int13_extended_verify ( int13, ix86 );
+			status = int13_extended_verify ( sandev, ix86 );
 			break;
 		case INT13_EXTENDED_SEEK:
-			status = int13_extended_seek ( int13, ix86 );
+			status = int13_extended_seek ( sandev, ix86 );
 			break;
 		case INT13_GET_EXTENDED_PARAMETERS:
-			status = int13_get_extended_parameters ( int13, ix86 );
+			status = int13_get_extended_parameters ( sandev, ix86 );
 			break;
 		case INT13_CDROM_STATUS_TERMINATE:
-			status = int13_cdrom_status_terminate ( int13, ix86 );
+			status = int13_cdrom_status_terminate ( sandev, ix86 );
 			break;
 		case INT13_CDROM_READ_BOOT_CATALOG:
-			status = int13_cdrom_read_boot_catalog ( int13, ix86 );
+			status = int13_cdrom_read_boot_catalog ( sandev, ix86 );
 			break;
 		default:
-			DBGC2 ( int13, "*** Unrecognised INT13 ***\n" );
+			DBGC2 ( sandev, "*** Unrecognised INT13 ***\n" );
 			status = -INT13_STATUS_INVALID;
 			break;
 		}
@@ -1451,8 +1119,8 @@ static __asmcall void int13 ( struct i386_all_regs *ix86 ) {
 		/* Negative status indicates an error */
 		if ( status < 0 ) {
 			status = -status;
-			DBGC ( int13, "INT13,%02x (%02x) failed with status "
-			       "%02x\n", ix86->regs.ah, int13->drive, status );
+			DBGC ( sandev, "INT13,%02x (%02x) failed with status "
+			       "%02x\n", ix86->regs.ah, sandev->drive, status );
 		} else {
 			ix86->flags &= ~CF;
 		}
@@ -1529,66 +1197,7 @@ static void int13_unhook_vector ( void ) {
 }
 
 /**
- * Check INT13 emulated drive flow control window
- *
- * @v int13		Emulated drive
- */
-static size_t int13_block_window ( struct int13_drive *int13 __unused ) {
-
-	/* We are never ready to receive data via this interface.
-	 * This prevents objects that support both block and stream
-	 * interfaces from attempting to send us stream data.
-	 */
-	return 0;
-}
-
-/**
- * Handle INT 13 emulated drive underlying block device closing
- *
- * @v int13		Emulated drive
- * @v rc		Reason for close
- */
-static void int13_block_close ( struct int13_drive *int13, int rc ) {
-
-	/* Any closing is an error from our point of view */
-	if ( rc == 0 )
-		rc = -ENOTCONN;
-
-	DBGC ( int13, "INT13 drive %02x went away: %s\n",
-	       int13->drive, strerror ( rc ) );
-
-	/* Record block device error code */
-	int13->block_rc = rc;
-
-	/* Shut down interfaces */
-	intf_restart ( &int13->block, rc );
-}
-
-/** INT 13 drive interface operations */
-static struct interface_operation int13_block_op[] = {
-	INTF_OP ( xfer_window, struct int13_drive *, int13_block_window ),
-	INTF_OP ( intf_close, struct int13_drive *, int13_block_close ),
-};
-
-/** INT 13 drive interface descriptor */
-static struct interface_descriptor int13_block_desc =
-	INTF_DESC ( struct int13_drive, block, int13_block_op );
-
-/**
- * Free INT 13 emulated drive
- *
- * @v refcnt		Reference count
- */
-static void int13_free ( struct refcnt *refcnt ) {
-	struct int13_drive *int13 =
-		container_of ( refcnt, struct int13_drive, refcnt );
-
-	uri_put ( int13->uri );
-	free ( int13 );
-}
-
-/**
- * Hook INT 13 emulated drive
+ * Hook INT 13 SAN device
  *
  * @v uri		URI
  * @v drive		Drive number
@@ -1598,9 +1207,11 @@ static void int13_free ( struct refcnt *refcnt ) {
  * the INT 13 interrupt vector (if not already hooked).
  */
 static int int13_hook ( struct uri *uri, unsigned int drive ) {
-	struct int13_drive *int13;
+	struct san_device *sandev;
+	struct int13_data *int13;
 	unsigned int natural_drive;
 	void *scratch;
+	int need_hook = ( ! have_sandevs() );
 	int rc;
 
 	/* Calculate natural drive number */
@@ -1611,60 +1222,49 @@ static int int13_hook ( struct uri *uri, unsigned int drive ) {
 	if ( ( drive & 0x7f ) == 0x7f )
 		drive = natural_drive;
 
-	/* Check that drive number is not in use */
-	list_for_each_entry ( int13, &int13s, list ) {
-		if ( int13->drive == drive ) {
-			rc = -EADDRINUSE;
-			goto err_in_use;
-		}
-	}
-
-	/* Allocate and initialise structure */
-	int13 = zalloc ( sizeof ( *int13 ) );
-	if ( ! int13 ) {
+	/* Allocate SAN device */
+	sandev = alloc_sandev ( uri, sizeof ( *int13 ) );
+	if ( ! sandev ) {
 		rc = -ENOMEM;
-		goto err_zalloc;
+		goto err_alloc;
 	}
-	ref_init ( &int13->refcnt, int13_free );
-	intf_init ( &int13->block, &int13_block_desc, &int13->refcnt );
-	int13->uri = uri_get ( uri );
-	int13->drive = drive;
+	sandev->drive = drive;
+	int13 = sandev->priv;
 	int13->natural_drive = natural_drive;
 
-	/* Open block device interface */
-	if ( ( rc = int13_reopen_block ( int13 ) ) != 0 )
-		goto err_reopen_block;
-
-	/* Read device capacity */
-	if ( ( rc = int13_read_capacity ( int13 ) ) != 0 )
-		goto err_read_capacity;
+	/* Register SAN device */
+	if ( ( rc = register_sandev ( sandev ) ) != 0 ) {
+		DBGC ( sandev, "INT13 drive %02x could not register: %s\n",
+		       sandev->drive, strerror ( rc ) );
+		goto err_register;
+	}
 
 	/* Allocate scratch area */
-	scratch = malloc ( int13_blksize ( int13 ) );
+	scratch = malloc ( sandev_blksize ( sandev ) );
 	if ( ! scratch )
 		goto err_alloc_scratch;
 
 	/* Parse parameters, if present */
-	if ( ( rc = int13_parse_iso9660 ( int13, scratch ) ) != 0 )
-		goto err_parse_iso9660;
+	if ( sandev->is_cdrom &&
+	     ( ( rc = int13_parse_eltorito ( sandev, scratch ) ) != 0 ) )
+		goto err_parse_eltorito;
 
-	/* Give drive a default geometry */
-	if ( ( rc = int13_guess_geometry ( int13, scratch ) ) != 0 )
+	/* Give drive a default geometry, if applicable */
+	if ( ( sandev_blksize ( sandev ) == INT13_BLKSIZE ) &&
+	     ( ( rc = int13_guess_geometry ( sandev, scratch ) ) != 0 ) )
 		goto err_guess_geometry;
 
-	DBGC ( int13, "INT13 drive %02x (naturally %02x) registered with C/H/S "
-	       "geometry %d/%d/%d\n", int13->drive, int13->natural_drive,
-	       int13->cylinders, int13->heads, int13->sectors_per_track );
+	DBGC ( sandev, "INT13 drive %02x (naturally %02x) registered with "
+	       "C/H/S geometry %d/%d/%d\n",
+	       sandev->drive, int13->natural_drive, int13->cylinders,
+	       int13->heads, int13->sectors_per_track );
 
 	/* Hook INT 13 vector if not already hooked */
-	if ( list_empty ( &int13s ) ) {
+	if ( need_hook ) {
 		int13_hook_vector();
 		devices_get();
 	}
 
-	/* Add to list of emulated drives */
-	list_add ( &int13->list, &int13s );
-
 	/* Update BIOS drive count */
 	int13_sync_num_drives();
 
@@ -1672,73 +1272,52 @@ static int int13_hook ( struct uri *uri, unsigned int drive ) {
 	return drive;
 
  err_guess_geometry:
- err_parse_iso9660:
+ err_parse_eltorito:
 	free ( scratch );
  err_alloc_scratch:
- err_read_capacity:
- err_reopen_block:
-	intf_shutdown ( &int13->block, rc );
-	ref_put ( &int13->refcnt );
- err_zalloc:
- err_in_use:
+	unregister_sandev ( sandev );
+ err_register:
+	sandev_put ( sandev );
+ err_alloc:
 	return rc;
 }
 
 /**
- * Find INT 13 emulated drive by drive number
- *
- * @v drive		Drive number
- * @ret int13		Emulated drive, or NULL
- */
-static struct int13_drive * int13_find ( unsigned int drive ) {
-	struct int13_drive *int13;
-
-	list_for_each_entry ( int13, &int13s, list ) {
-		if ( int13->drive == drive )
-			return int13;
-	}
-	return NULL;
-}
-
-/**
- * Unhook INT 13 emulated drive
+ * Unhook INT 13 SAN device
  *
  * @v drive		Drive number
  *
  * Unregisters the drive from the INT 13 emulation subsystem.  If this
- * is the last emulated drive, the INT 13 vector is unhooked (if
+ * is the last SAN device, the INT 13 vector is unhooked (if
  * possible).
  */
 static void int13_unhook ( unsigned int drive ) {
-	struct int13_drive *int13;
+	struct san_device *sandev;
 
 	/* Find drive */
-	int13 = int13_find ( drive );
-	if ( ! int13 ) {
-		DBG ( "INT13 cannot find emulated drive %02x\n", drive );
+	sandev = sandev_find ( drive );
+	if ( ! sandev ) {
+		DBG ( "INT13 cannot find drive %02x\n", drive );
 		return;
 	}
 
-	/* Shut down interfaces */
-	intf_shutdown ( &int13->block, 0 );
-
-	/* Remove from list of emulated drives */
-	list_del ( &int13->list );
+	/* Unregister SAN device */
+	unregister_sandev ( sandev );
 
 	/* Should adjust BIOS drive count, but it's difficult
 	 * to do so reliably.
 	 */
 
-	DBGC ( int13, "INT13 drive %02x unregistered\n", int13->drive );
+	DBGC ( sandev, "INT13 drive %02x unregistered\n", sandev->drive );
 
 	/* Unhook INT 13 vector if no more drives */
-	if ( list_empty ( &int13s ) ) {
+	if ( ! have_sandevs() ) {
 		devices_put();
 		int13_unhook_vector();
 	}
 
-	/* Drop list's reference to drive */
-	ref_put ( &int13->refcnt );
+	/* Drop reference to drive */
+	sandev_put ( sandev );
 }
 
 /**
@@ -1939,26 +1518,26 @@ static union xbft_table __bss16 ( xbftab ) __attribute__ (( aligned ( 16 ) ));
 #define xbftab __use_data16 ( xbftab )
 
 /**
- * Describe INT 13 emulated drive for SAN-booted operating system
+ * Describe SAN device for SAN-booted operating system
  *
  * @v drive		Drive number
  * @ret rc		Return status code
  */
 static int int13_describe ( unsigned int drive ) {
-	struct int13_drive *int13;
+	struct san_device *sandev;
 	struct segoff xbft_address;
 	int rc;
 
 	/* Find drive */
-	int13 = int13_find ( drive );
-	if ( ! int13 ) {
-		DBG ( "INT13 cannot find emulated drive %02x\n", drive );
+	sandev = sandev_find ( drive );
+	if ( ! sandev ) {
+		DBG ( "INT13 cannot find drive %02x\n", drive );
 		return -ENODEV;
 	}
 
 	/* Reopen block device if necessary */
-	if ( ( int13->block_rc != 0 ) &&
-	     ( ( rc = int13_reopen_block ( int13 ) ) != 0 ) )
+	if ( sandev_needs_reopen ( sandev ) &&
+	     ( ( rc = sandev_reopen ( sandev ) ) != 0 ) )
 		return rc;
 
 	/* Clear table */
@@ -1971,10 +1550,10 @@ static int int13_describe ( unsigned int drive ) {
 		  sizeof ( xbftab.acpi.oem_table_id ) );
 
 	/* Fill in remaining parameters */
-	if ( ( rc = acpi_describe ( &int13->block, &xbftab.acpi,
+	if ( ( rc = acpi_describe ( &sandev->block, &xbftab.acpi,
 				    sizeof ( xbftab ) ) ) != 0 ) {
-		DBGC ( int13, "INT13 drive %02x could not create ACPI "
-		       "description: %s\n", int13->drive, strerror ( rc ) );
+		DBGC ( sandev, "INT13 drive %02x could not create ACPI "
+		       "description: %s\n", sandev->drive, strerror ( rc ) );
 		return rc;
 	}
 
@@ -1982,9 +1561,9 @@ static int int13_describe ( unsigned int drive ) {
 	acpi_fix_checksum ( &xbftab.acpi );
 	xbft_address.segment = rm_ds;
 	xbft_address.offset = __from_data16 ( &xbftab );
-	DBGC ( int13, "INT13 drive %02x described using boot firmware "
-	       "table:\n", int13->drive );
-	DBGC_HDA ( int13, xbft_address, &xbftab,
+	DBGC ( sandev, "INT13 drive %02x described using boot firmware "
+	       "table:\n", sandev->drive );
+	DBGC_HDA ( sandev, xbft_address, &xbftab,
 		   le32_to_cpu ( xbftab.acpi.length ) );
 
 	return 0;