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The RigidDiskBlock (RDB) standard was borne out of the same development
effort as HD_SCSICMD and as a result has a heavy bias towards SCSI.
However, there is nothing in the RDB specification that makes it unusable
for devices using other bus protocols. The XT style disks used in the
A590 also support the RDB standard.
The RDB scheme was designed to allow the automatic mounting of all
partitions on a hard drive and subsequent booting from the highest
priority partition even if it has a soft loaded filing system. Disks can
be removed from one controller and plugged into another (supporting the
RDB scheme) and will carry with it all the necessary information for
mounting and booting with them.
The preferred method of creating RigidDiskBlocks is with the HDToolBox
program supplied by Commodore. Most controllers include an RDB editor or
utility.
When a driver is initialized, it uses the information contained in the RDB
to mount the required partitions and mark them as bootable if needed. The
driver is also responsible for loading any filing systems that are
required if they are not already available on the filesystem.resource
list. File- systems are added to the resource according to DosType and
version number.
The following is a listing of devices/hardblocks.h that describes all the
fields in the RDB specification.
/*--------------------------------------------------------------------
*
* This file describes blocks of data that exist on a hard disk
* to describe that disk. They are not generically accessable to
* the user as they do not appear on any DOS drive. The blocks
* are tagged with a unique identifier, checksummed, and linked
* together. The root of these blocks is the RigidDiskBlock.
*
* The RigidDiskBlock must exist on the disk within the first
* RDB_LOCATION_LIMIT blocks. This inhibits the use of the zero
* cylinder in an AmigaDOS partition: although it is strictly
* possible to store the RigidDiskBlock data in the reserved
* area of a partition, this practice is discouraged since the
* reserved blocks of a partition are overwritten by "Format",
* "Install", "DiskCopy", etc. The recommended disk layout,
* then, is to use the first cylinder(s) to store all the drive
* data specified by these blocks: i.e. partition descriptions,
* file system load images, drive bad block maps, spare blocks,
* etc.
*
* Though only 512 byte blocks are currently supported by the
* file system, this proposal tries to be forward-looking by
* making the block size explicit, and by using only the first
* 256 bytes for all blocks but the LoadSeg data.
*
*------------------------------------------------------------------*/
/*
* NOTE
* optional block addresses below contain $ffffffff to indicate
* a NULL address, as zero is a valid address
*/
struct RigidDiskBlock {
ULONG rdb_ID; /* 4 character identifier */
ULONG rdb_SummedLongs; /* size of this checksummed structure */
LONG rdb_ChkSum; /* block checksum (longword sum to zero) */
ULONG rdb_HostID; /* SCSI Target ID of host */
ULONG rdb_BlockBytes; /* size of disk blocks */
ULONG rdb_Flags; /* see below for defines */
/* block list heads */
ULONG rdb_BadBlockList; /* optional bad block list */
ULONG rdb_PartitionList; /* optional first partition block */
ULONG rdb_FileSysHeaderList; /* optional file system header block */
ULONG rdb_DriveInit; /* optional drive-specific init code */
/* DriveInit(lun,rdb,ior): */
/* "C" stk & d0/a0/a1 */
ULONG rdb_Reserved1[6]; /* set to $ffffffff */
/* physical drive characteristics */
ULONG rdb_Cylinders; /* number of drive cylinders */
ULONG rdb_Sectors; /* sectors per track */
ULONG rdb_Heads; /* number of drive heads */
ULONG rdb_Interleave; /* interleave */
ULONG rdb_Park; /* landing zone cylinder */
ULONG rdb_Reserved2[3];
ULONG rdb_WritePreComp; /* starting cylinder: write precompensation */
ULONG rdb_ReducedWrite; /* starting cylinder: reduced write current */
ULONG rdb_StepRate; /* drive step rate */
ULONG rdb_Reserved3[5];
/* logical drive characteristics */
ULONG rdb_RDBBlocksLo; /* low block of range reserved for
/* hardblocks */
ULONG rdb_RDBBlocksHi; /* high block of range for these hardblocks */
ULONG rdb_LoCylinder; /* low cylinder of partitionable disk area */
ULONG rdb_HiCylinder; /* high cylinder of partitionable data area */
ULONG rdb_CylBlocks; /* number of blocks available per cylinder */
ULONG rdb_AutoParkSeconds; /* zero for no auto park */
ULONG rdb_HighRDSKBlock; /* highest block used by RDSK */
/* (not including replacement bad blocks) */
ULONG rdb_Reserved4;
/* drive identification */
char rdb_DiskVendor[8];
char rdb_DiskProduct[16];
char rdb_DiskRevision[4];
char rdb_ControllerVendor[8];
char rdb_ControllerProduct[16];
char rdb_ControllerRevision[4];
ULONG rdb_Reserved5[10];
};
#define IDNAME_RIGIDDISK 0x5244534B /* 'RDSK' */
#define RDB_LOCATION_LIMIT 16
#define RDBFB_LAST 0 /* no disks exist to be configured after */
#define RDBFF_LAST 0x01L /* this one on this controller */
#define RDBFB_LASTLUN 1 /* no LUNs exist to be configured */
#define RDBFF_LASTLUN 0x02L /* greater than this one at this SCSI */
/* Target ID */
#define RDBFB_LASTTID 2 /* no Target IDs exist to be configured */
#define RDBFF_LASTTID 0x04L /* greater than this one on this */
/* SCSI bus */
#define RDBFB_NORESELECT 3 /* don't bother trying to perform */
/* reselection when talking */
#define RDBFF_NORESELECT 0x08L /* to this drive */
#define RDBFB_DISKID 4 /* rdb_Disk... identification valid */
#define RDBFF_DISKID 0x10L
#define RDBFB_CTRLRID 5 /* rdb_Controller...identification valid */
#define RDBFF_CTRLRID 0x20L
/* added 7/20/89 by commodore: */
#define RDBFB_SYNCH 6 /* drive supports scsi synchronous mode */
#define RDBFF_SYNCH 0x40L /* DANGEROUS TO USE IF IT DOESN'T! */
/*------------------------------------------------------------------*/
struct BadBlockEntry {
ULONG bbe_BadBlock; /* block number of bad block */
ULONG bbe_GoodBlock; /* block number of replacement block */
};
struct BadBlockBlock {
ULONG bbb_ID; /* 4 character identifier */
ULONG bbb_SummedLongs; /* size of this checksummed structure */
LONG bbb_ChkSum; /* block checksum (longword sum to zero) */
ULONG bbb_HostID; /* SCSI Target ID of host */
ULONG bbb_Next; /* block number of the next BadBlockBlock */
ULONG bbb_Reserved;
struct BadBlockEntry bbb_BlockPairs[61]; /* bad block entry pairs */
/* note [61] assumes 512 byte blocks */
};
#define IDNAME_BADBLOCK 0x42414442 /* 'BADB' */
/*------------------------------------------------------------------*/
struct PartitionBlock {
ULONG pb_ID; /* 4 character identifier */
ULONG pb_SummedLongs; /* size of this checksummed structure */
LONG pb_ChkSum; /* block checksum (longword sum to zero) */
ULONG pb_HostID; /* SCSI Target ID of host */
ULONG pb_Next; /* block number of the next PartitionBlock */
ULONG pb_Flags; /* see below for defines */
ULONG pb_Reserved1[2];
ULONG pb_DevFlags; /* preferred flags for OpenDevice */
UBYTE pb_DriveName[32]; /* preferred DOS device name: BSTR form */
/* (not used if this name is in use) */
ULONG pb_Reserved2[15]; /* filler to 32 longwords */
ULONG pb_Environment[17]; /* environment vector for this partition */
ULONG pb_EReserved[15]; /* reserved for future environment vector */
};
#define IDNAME_PARTITION 0x50415254 /* 'PART' */
#define PBFB_BOOTABLE 0 /* this partition intended to be bootable */
#define PBFF_BOOTABLE 1L /* (expected directories and files exist) */
#define PBFB_NOMOUNT 1 /* do not mount this partition (manually */
#define PBFF_NOMOUNT 2L /* mounted, but space reserved here) */
/*------------------------------------------------------------------*/
struct FileSysHeaderBlock {
ULONG fhb_ID; /* 4 character identifier */
ULONG fhb_SummedLongs; /* size of this checksummed structure */
LONG fhb_ChkSum; /* block checksum (longword sum to zero) */
ULONG fhb_HostID; /* SCSI Target ID of host */
ULONG fhb_Next; /* block number of next FileSysHeaderBlock */
ULONG fhb_Flags; /* see below for defines */
ULONG fhb_Reserved1[2];
ULONG fhb_DosType; /* file system description: match this with */
/* partition environment's DE_DOSTYPE entry */
ULONG fhb_Version; /* release version of this code */
ULONG fhb_PatchFlags; /* bits set for those of the following that */
/* need to be substituted into a standard */
/* device node for this file system: e.g. */
/* 0x180 to substitute SegList & GlobalVec */
ULONG fhb_Type; /* device node type: zero */
ULONG fhb_Task; /* standard dos "task" field: zero */
ULONG fhb_Lock; /* not used for devices: zero */
ULONG fhb_Handler; /* filename to loadseg: zero placeholder */
ULONG fhb_StackSize; /* stacksize to use when starting task */
LONG fhb_Priority; /* task priority when starting task */
LONG fhb_Startup; /* startup msg: zero placeholder */
LONG fhb_SegListBlocks; /* first of linked list of LoadSegBlocks: */
/* note that this entry requires some */
/* processing before substitution */
LONG fhb_GlobalVec; /* BCPL global vector when starting task */
ULONG fhb_Reserved2[23];/* (those reserved by PatchFlags) */
ULONG fhb_Reserved3[21];
};
#define IDNAME_FILESYSHEADER 0x46534844 /* 'FSHD' */
/*------------------------------------------------------------------*/
struct LoadSegBlock {
ULONG lsb_ID; /* 4 character identifier */
ULONG lsb_SummedLongs; /* size of this checksummed structure */
LONG lsb_ChkSum; /* block checksum (longword sum to zero) */
ULONG lsb_HostID; /* SCSI Target ID of host */
ULONG lsb_Next; /* block number of the next LoadSegBlock */
ULONG lsb_LoadData[123]; /* data for "loadseg" */
/* note [123] assumes 512 byte blocks */
};
#define IDNAME_LOADSEG
how a driver uses rdb
alien filing systems