Meeting Pearls 3/Meeting_Pearls_III.iso/Pearls/disk/DiskMon/ded/ded.doc

Text File | 1993-11-02 | 19KB | 680 lines

                 Disk-Editor, Version 1.1, User documentation
                             Edition 3-Nov-1993
                    Copyright 1992,3 Misoftware Computing




1. I'm sorry for my bad English.
--------------------------------

2. Requirements
---------------

   Hardware:

   An  AMIGA, Version 1.2 or higher (tested on 1.3, 2.0 and 3.0, next version
will be 2.0+ only), NTSC or PAL, cca 100KB of memory free, 5 bytes per sector
for  bitmap (for standard floppy format it's about 8800 bytes), 512 bytes for
sector data, some memory for CD, drive, disk...


   Software:

   Arp  library,  Req  or Reqtools library.  If you want nicer design, you need
Reqtools library.  If DED is unable to open it, it will use Req, but the design
has been made for Reqtools.


3. Design
---------

   On  the  screen title, there is the program version and number of sectors in
memory  displayed.   In  the  bottom  of  the  screen,  there  is a status line
containing  type  of  current sector, position in it, its number, its flags and
total free memory.

3.1 Type

   Program recognises 21 types of sectors:  BOOT, ROOT, USERDIR, FHEADER, EXT.,
DATA,  BITMAP,  DIRCACHE,  LDIR, LFILE, LSEG, FSHD, PART., BAD BLK, RIGID, BMAP
EXT,???, SUSPECT, BITMAP?, FREE, DATA?

BOOT     - Bootblock
ROOT     - Rootblock
USERDIR  - User directory
FHEADER  - File header
EXT.     - Extension of file header
DATA     - Data block
BITMAP   - Bitmap block
DIRCACHE - Directory  cache  block (introduced in  OS V39, DED may  handle them
           under any OS version including 1.2)
LDIR     - Linked directory (introduced in  OS V36, DED may  handle  them under
           any OS version including 1.2)
LFILE    - Linked fileheader (introduced in  OS V36, DED may  handle them under
           any OS version including 1.2)
LSEG     - Load segment block
FSHD     - Filesystem header block
PART.    - Partition block
BAD BLK  - Replacement of bad block
RIGID    - Disk rigid block
BMAP EXT - Bitmap extension block

???      - Unknown type, but may be free (use "Load root & bitmap" for correct
           identification)
SUSPECT  - Unknown type, but allocated or something very suspicious
BITMAP?  - Sector can be a bitmap
FREE     - Free block
DATA?    - May be  a  FFS data  block (use "Load  root  &  bitmap" for correct
           identification)

3.2 Position in block

   Format  of  numbers:  there are six numbers, separated by slashes:  pos in
bytes  in  dec/pos  in words in dec/pos in longs in dec space pos in bytes in
hex/pos in words in hex/pos in longs in hex.

   If you edit bitmap block in DOS edit mode, the number of the sector, pointed
to by mouse, is displayed here, instead.

3.3 Block

   Number of block, pointed to by the cursor.

3.4 Sector flags

1st character: Sector is changed   *=changed, #=not changed
2nd character: Sector is selected  +=selected, #=not selected
3rd character: Checksum            G=good, B=bad, Nothing=has no checksum
4th character: Status              B=Busy

3.5 Free memory

   Current amount of total free memory.


4. Control
----------

 DED can be controlled using:

  - menus

  - cursor keys - move the cursor by one position in some way

  - up and down arrows with shift - move the cursor by one screen

  - up and down arrows with alt - move the cursor by 12 lines

  - left and right arrows with alt - move the cursor by one byte

  - TAB key - switches between ASCII and number edit modes

  - CTRL and up/down/left/right - hotkeys for
      Parent/Descendant/Previous object/Next object menu functions

  -  F-key  functions - If you press CTRL + one of the F-keys, you may set your
own  ASCII-code  of  this F-key.  But this code is valid only in the edit mode.
CTRL  +  SHIFT + one of the F-keys => you will have to enter sector number.  If
you  press  SHIFT  and  this F-key, DED will jump on sector you defined before.
You can clear the sector number by entering empty string or -1.


   In  number  gadgets,  you can enter an expression.  Expressions can contain
numbers,  operators  (see  the  table  below),  variables (a-z), $ followed by
hexadecimal  number,  <  (means:   minimal  allowed value), > (maximal allowed
value).   If  you want to set a variable, you must use the calculator function
to do it.

   Operators: (sorted by priority)

    *,/        multiplication, division
    +,-        addition, subtraction
    &          logical AND
    ^,|        logical XOR and OR

   Control in DOS edit mode:

    - CTRL and up/down/left/right - hotkeys for
        Parent/Descendant/Previous object/Next object menu functions

    - up or left - same as menuitem "Previous sector"

    - down or right - same as menuitem "Next sector"

    - menuitem "Jump to byte ..." is changed to "Jump to bitmap flag of sector
      ..."

    - You may change any information (including sector type) by clicking on it.
      You  cannot change BOOT, BITMAP, FREE and DATA? sector types and the ROOT
      type can be switched only between ROOT and SUSPECT types.

    - SHIFT + F-key functions (see above)

    - up and down arrows with shift - scroll the display

5. Testing
----------

   This  version  has  been written on AMIGA 500 with 2MB of RAM, one external
disk drive and system 1.3.

 Tested on:

     My AMIGA
     AMIGA 500+ with 6 MB of RAM, 50MB hard disk and kickstart 2.0
     AMIGA 500 with 1MB of chip and 1MB of fast RAM, one external drive
        and a 45 MB hard-disk.
     AMIGA 1200 with 2 MB of CHIP-RAM, 80MB hard disk


6. Miscellaneous
----------------

   This  program  is freely distributable, but the copyright remains with the
author at all times.  It's provided "as is"; no warranties are made.  All use
Is at your own risk, and no liability or responsibility is assumed.

   This  is a first public released version.  Here are still some unknown bugs,
but I don't know where.  If you know some, please write to:

     Internet E-mail:
            [e-mail]

         or Michal Kara
            Krosenska 543
            Praha 8-Troja
            181 00
            Czech republic


   If  you  call DED from CLI, you can also specify mounted device by giving it
as an argument - for example "ded df0:".


7. Thanks
---------

   Thanks  to  Martin Mares of MJSoft System Software for testing, critics and
some information about AMIGA system,

   Pavel Troller of SinSoft for language censoring,

   Honza Kratochvil ("LACE") for testing and some ideas

   and Petr Cisar (PCSoft) & "mr. Zub" for risking integrity of their hards.


   No thanks to PC for its existency.


8. History
----------

   History is stored in the ded.history file.


9. Plans for future
-------------------

 - Check and repair disk (The Re-hash function in this version has some
   repairing effects...)

 - Recover actions

 - User selectable screen mode

 - Wildcards in search

 - Optimize the code

 - Dynamic bitmap of sectors (less than 5 bytes for every sector)

 - Variable length of block

 - The next release will be probably 2.0+ only (some 2.0+ features will be
   added)

 - Use only reqtools.library, no req

10. Appendixes
--------------

                                APPENDIX A
                              DOS STRUCTURES

(Thanks to Martin Mares for most of these structures)

Here  are  dos  structures  for  the  Old  File  System (OFS), offsets are in
longs:

ROOT BLOCK:

This block is in the middle of the medium. It's the root directory.

0 T.SHORT (=2)
1 0
2 0
3 HASH TABLE SIZE
4 0
5 CHECKSUM
6 HASH TABLE
...
SIZE-50 BITMAP FLAG (TRUE=BITMAP IS VALID)
SIZE-49 BITMAPBLOCKS
...
SIZE-24 BITMAP EXTENSION BLOCK
SIZE-23 DAYS LAST ACCESS
SIZE-22 MINS LAST ACCESS
SIZE-21 TICKS LAST ACCESS
SIZE-20 DISK NAME
...
SIZE-7 CREATE DAYS
SIZE-6 CREATE MINS
SIZE-5 CREATE TICKS
SIZE-4 0
SIZE-3 0
SIZE-2 FIRST DIRECTORY CACHE BLOCK
SIZE-1 ST.ROOT (=1)


USER DIR:

0 T.SHORT (=2)
1 POINTER TO SELF
2 0
3 0
4 0
5 CHECKSUM
6 HASH TABLE
...
SIZE-50 NOT USED
SIZE-48 PROTECTION BITS
SIZE-47 0
SIZE-46 COMMENT
...
SIZE-23 DAYS LAST ACCES
SIZE-22 MINS LAST ACCES
SIZE-21 TICKS LAST ACCES
SIZE-20 DIRECTORY NAME
...
SIZE-11 PREVIOUS BLOCK IN LINK-LIST - This value is always NULL.
SIZE-10 NEXT BLOCK IN LINK-LIST
SIZE-4 HASH CHAIN (NEXT ENTRY WITH SAME HASH VALUE)
SIZE-3 PARENT DIRECTORY
SIZE-2 FIRST DIRECTORY CACHE BLOCK
SIZE-1 ST.USERDIR (=2)


FILE HEADER:

0 T.SHORT (=2)
1 POINTER TO SELF
2 # OF DATA BLOCKS IN THIS PART
3 0
4 1.ST DATA BLOCK
5 CHECKSUM
6 ...

DATABLOCKS-
SIZE-52 2nd DATA BLOCK
SIZE-51 1ST DATA BLOCK
SIZE-50 NOT USED
SIZE-48 PROTECTION BITS
SIZE-47 BYTE SIZE
SIZE-46 COMMENT
...
SIZE-23 DAYS LAST ACCES
SIZE-22 MINS LAST ACCES
SIZE-21 TICKS LAST ACCES
SIZE-20 FILE NAME
...
SIZE-11 PREVIOUS BLOCK IN LINK-LIST - This value is always NULL.
SIZE-10 NEXT BLOCK IN LINK-LIST
SIZE-4 NEXT ENTRY WITH SAME HASH VALUE
SIZE-3 PARENT DIRECTORY
SIZE-2 POINTER TO EXTENSION OR NULL
SIZE-1 ST.FILE (=-3)


EXTENSION OF FILE HEADER:

0 T.LIST (=16)
1 POINTER TO SELF
2 # OF DATA BLOCKS IN THIS PART
3 0
4 0
5 CHECKSUM
6 ...

DATABLOCKS-
SIZE-52 2nd DATA BLOCK
SIZE-51 1ST DATA BLOCK
SIZE-50 NOT USED
SIZE-4 0
SIZE-3 FILE HEADER
SIZE-2 POINTER TO EXTENSION OR NULL
SIZE-1 ST.FILE (=-3)


DATA BLOCK:

0 T.DATA (8)
1 POINTER TO FILE HEADER
2 NUMBER IN FILE (1ST,2ND,20TH DATA BLOCK)
3 DATA SIZE
4 NEXT DATA BLOCK OR NULL
5 CHECKSUM
6 DATA
...

BITMAP EXTENSION BLOCK:

   If  there's  more than 25 bitmap sectors, pointers to next bitmap blocks are
stored  in this block.  All longs (except the last one) are used as pointers to
the  bitmap blocks.  Last long points to the next BITMAP EXTENSION BLOCK (if it
exists).

   0 BITMAP BLOCK POINTERS
   ...
   SIZE-1 NEXT BITMAP EXTENSION BLOCK


BITMAP:

   Bitmap is stored in longs.  The bootblocks are not stored in the bitmap.  If
there  are  two bootblocks, the first bit (Bit #0) of the first long of data is
for  sector #2.  The second bit (bit #1) of the third long is for sector #67...
If  the bit is clear, sector is allocated.  In dos edit mode, DED converts this
user  unfriendly  defined  rule  so  sectors are displayed consecutively on the
screen.

0 CHECKSUM
1 DATA
...


For  Fast  File  System  (FFS) it's the same, but data block contain only data
(512 bytes).

DIRECTORY CACHE BLOCK:
0 (21)
1 SELFPOINTER
2 POINTER TO DIRECTORY
3 NUMBER ITEMS STORED IN THIS BLOCK
4 NEXT DIRECTORY CACHE BLOCK
5 CHECKSUM
6 - FIRST RECORD

  RECORD STRUCTURE: ( !!! OFFSETS ARE IN BYTES !!! )

0 POINTER TO FILEHEADER OR USERDIR OF THIS RECORD
4 SIZE OF FILE
8 PROTECTION BITS
12 0
16 DAYS LAST ACCES
18 MINS LAST ACCES
20 TICKS LAST ACCES
22 RECORD TYPE ($FD=FILE, $FC=LINKED FILE, $02=DIR, $04=LINKED DIR)
23 NAME (BSTR)
   COMMENT (BSTR)
   THERE MAY BE NULL BYTE (FOR WORD-ALIGNMENT)


LINKED FILE:
0 T.SHORT (=2)
1 SELFPOINTER
2 0
3 0
4 0
5 CHECKSUM
SIZE-23 DAYS LAST ACCESS
SIZE-22 MINS LAST ACCESS
SIZE-21 TICKS LAST ACCESS
SIZE-20 FILE NAME
...
SIZE-11 PREVIOUS BLOCK IN LINK-LIST
SIZE-10 NEXT BLOCK IN LINK-LIST
SIZE-4 NEXT ENTRY WITH SAME HASH VALUE
SIZE-3 PARENT DIRECTORY
SIZE-1 ST.LINKED FILE (=-4)


LINKED DIRECTORY:
0 T.SHORT (=2)
1 POINTER TO SELF
2 0
3 0
4 0
5 CHECKSUM
...
SIZE-23 DAYS LAST ACCESS
SIZE-22 MINS LAST ACCESS
SIZE-21 TICKS LAST ACCESS
SIZE-20 DIRECTORY NAME
...
SIZE-11 PREVIOUS BLOCK IN LINK-LIST
SIZE-10 NEXT BLOCK IN LINK-LIST
SIZE-4 NEXT ENTRY WITH SAME HASH VALUE
SIZE-3 PARENT DIRECTORY
SIZE-1 ST.LINKED USERDIR (=4)


The  following  structures  and  texts were taken from the devices/hardblocks.i
include file.

   Next  types  are  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.

   NOTE:   Optional  block addresses below contain $FFFFFFFF to indicate a NULL
address.


Rigid disk block:

0  ID - text "RDSK"
1  Size of this checksummed structure (in longs)
2  Block checksum
3  SCSI Target ID of host
4  Size of disk blocks (in bytes)
5  Flags  -  Bit  0  =  no  disks exist to be configured after this one on this
                        controller
             Bit  1  =  no LUNs exist to be configured greater than this one at
                        this SCSI Target ID
             Bit 2 = no Target IDs exist to be configured greater than this one
                     on this SCSI bus
             Bit 3 = don't bother trying to perform reselection when talking to
                     this drive
             Bit 4 = Disk identification valid
             Bit 5 = Controller identification valid
             Bit 6 = Drive supports scsi synchronous mode - CAN BE DANGEROUS TO
                     USE IF IT DOESN'T! (added 20-Jul-89)

6  Optional bad block list
7  Optional first partition block (PART)
8  Optional fule system header block (FSHD)
9  Optional  drive-specific  init  code  *DriveInit(lun,rdb,ior):   "C"  stk  &
   d0/a0/a1)
10 Six longs sets to -1
15 Number of drive cylinders
17 Sectors per track
18 Number of drive heads
19 Interleave
20 Landing zone cylinder (would be negative number)
21 Three unused longs
24 Starting cylinder: write precompensation
25 Starting cylinder: reduced write current
26 Drive step rate
27 Five unused longs
32 Low block of range reserved for hardblocks
33 High block of range for these hardblocks
34 Low cylinder of partitionable disk area
35 High cylinder of partitionable data area
36 Number of blocks available per cylinder
37 Seconds needed for autopark - zero for no auto park
38 Highest block used by RDSK (Not including replacement bad blocks)
39 One unused long
40 Two longs for disk vendor
42 Four longs for disk product
45 One long for disk revision
47 Two longs for controller vendor
49 Four longs for controller product
53 One long for controller revision
54 Ten unused longs


Bad block(s) block:

0 ID - text "BADB"
1 Size of this checksummed structure (in longs)
2 Block checksum
3 SCSI Target ID of host
4 Block number of the next Bad block(s) block (link)
5 One unused long
6 There are block pairs - First long  - pointer to bad block to replace to
                          Second long - pointer to good block which replaces it


Partition block:

0  ID - text "PART"
1  Size of this checksummed structure (in longs)
2  Block checksum
3  SCSI Target ID of host
4  Block number of the next Partition block (or -1)
5  Flags - Bit 0 = This partition is bootable
           Bit 1 = Do not automount this partition (e.g.  manually mounted, but
                   space reserved here)
6  Two reserved longs
8  Preferred flags for OpenDevice
9  Eight longs for BSRT device name (e.g. DH0)
17 Fiveteen unused longs

   The   following   structure   (dos   environment)   was   taken   from   the
dos/filehandler.i include file (but Partition block structure continuing!).

32 Size of table (in long without this, usually 16)
33 Size of block in longs
34 Sector org (??? - doc says that it's unused, set to 0)
35 Surfaces = number of heads
36 Sectors per block (not used, set to 1)
37 Number of blocks per track
38 Number  of  blocks  reserved  by  DOS  at  the start of the  partition (e.g.
   bootblock)
39 Number of blocks reserved by DOS at the end of the partition (mostly zero)
40 Interleave
41 Starting cylinder of the partition
42 Last cylinder of the partition
43 Initial number of DOS buffers
44 Type of memory to allocate for buffers
45 Max number of bytes to transfer at a time
46 Address mask to block out certain memory (usually $FFFFFE)
47 Boot priority
48 Dos  type  ASCII  (HEX) string  showing filesystem type (like in bootblock):
   0x444F5300 is old filesystem
   0x444F5301 is fast file system
49 Fiveteen reserved longs


File system header:

0  ID text "FSHD"
1  Size of this checksummed structure (in longs)
2  Block checksum
3  SCSI Target ID of host
4  Size of disk blocks (in bytes)
5  Flags - No flags defined (???)
6  Two reserved longs
8  Dos  type  ASCII  (HEX) string  showing filesystem type (like in bootblock):
   0x444F5300 is old filesystem
   0x444F5301 is fast file system
9  Two words specifying release version of this code
10 Patching flags for next nine (or in future more) entries specifies, which of
   these have to be patched to the device structure.  Bit 0 = patch Device node
   type,  bit  7  =  patch  Segment list ..., $180 to patch Segment list Global
   vector.

   The  following  (device node) structure was taken from the dos/filehandler.i
include file (but File system header block structure continuing!).

11 Type - always 0 for dos "devices"
12 CPTR  to  task.   If this  is null when the node is accesses, a task will be
   started up
13 BPTR to lock - not used for devices - leave null
14 BSTR Handler - filename to loadseg (if seglist is null)
15 Stacksize to use when starting task
16 Task priority when starting task
17 BPTR to startup msg: FileSysStartupMsg for disks
18 Pointer to first Load file system segment (LSEG) block.
19 BPTR to global vector - BCPL global  vector to use when starting a task.  -1
means that the Segment list (see long 19) is not for a bcpl program, so the dos
won't  try and construct one.  0 tell the dos that you obey BCPL linkage rules,
and that it should construct a global vector for you.
20 Twenty three reserved longs
43 Twenty one reserved longs


Load file system segment (these block contains filesystem):

0 ID - text "LSEG"
1 Size of this checksummed structure (in longs)
2 Block checksum
3 SCSI Target ID of host
4 Block number of the next Load file system segment block (link)
5 There is 123 longs of data
...


                                APPENDIX B
                           THE HASHING FUNCTION

   Hashing  is  a very good way to speed up the disk access.  In AmigaDos, it's
used  in  directories  (including ROOT).  One block contains 72 hashchains.  If
some  items  have  the same hash value, the long in the directory points to the
first  block,  the  entry  'next entry with same hash value' of the first block
points to the second block...

   HASH_VALUE  is number of long, where the number of block is stored in, name
is the name of object and name[n] is the n-th character of the string.

HASH_VALUE=f(STRLEN[name]) MOD 72 + 6

      f(0)=STRLEN(name)
      f(n)=13*f(n-1)+TOUPPER(name[n])

   Here is source of hashing function.
INPUT:  A0 = String to hash value compute to
OUTPUT: D0 = Hash value

hash_fn    move.l    a0,-(a7)
    moveq    #-1,d1
1$    add.l    #1,d1
    tst.b    (a0)+
    bne    1$
    move.l    (a7)+,a0
3$    move.b    (a0)+,d0
    beq    2$
    mulu    #13,d1
    bsr    to_upper
    and.w    #$00FF,d0
    add.w    d0,d1
    and.w    #$7FF,d1
    bra    3$

2$    move.l    d1,d0
    rts