haiku/docs/develop/partitioning_systems/sun.rst

Partitioning system for Sun Sparc machines
==========================================

Infos extracted from `File System Forensic Analysis, Brian Carrier <urn:isbn:0-134-43954-6>`_
and in particular the `online copy here <https://books.google.fr/books?id=Zpm9CgAAQBAJ&lpg=PT159&ots=6LIQ6blJCF&dq=solaris%20vtoc%20structure&hl=fr&pg=PT159#v=onepage&q=solaris%20vtoc%20structure&f=false>`_), tables 6.9 and 6.10.

The format is called VTOC (volume table of contents). It is stored at offset 0
on-disk. All values are big endian.

Note that the x86 version of Solaris uses a different layout.

+------------+--------------------------------+
| Byte offset|Description                     |
+============+================================+
| 0-127      |ASCII disk label                |
+------------+--------------------------------+
| 128-261    |VTOC *                          |
+------------+--------------------------------+
| 262-263    |Sectors to skip when writing    |
+------------+--------------------------------+
| 264-265    |Setors to skip when reading     |
+------------+--------------------------------+
| 266-419    |Reserved                        |
+------------+--------------------------------+
| 420-421    |Disk speed                      |
+------------+--------------------------------+
| 422-423    |Number of cylinders             |
+------------+--------------------------------+
| 424-425    |Alternates per cylinder         |
+------------+--------------------------------+
| 426-429    |Reserved                        |
+------------+--------------------------------+
| 430-431    |Interleave                      |
+------------+--------------------------------+
| 432-433    |Number of data cylinders        |
+------------+--------------------------------+
| 434-435    |Number of alternate cylinders   |
+------------+--------------------------------+
| 436-437    |Number of heads                 |
+------------+--------------------------------+
| 438-439    |Number of sectors per track     |
+------------+--------------------------------+
| 440-443    |Reserved                        |
+------------+--------------------------------+
| 444-451    |Partition 1 disk map            |
+------------+--------------------------------+
| ...        |More partition disk maps        |
+------------+--------------------------------+
| 500-507    |Partition 8 disk map            |
+------------+--------------------------------+
| 508-509    |Signature (0xDABE)              |
+------------+--------------------------------+
| 510-511    |Checksum                        |
+------------+--------------------------------+

The VTOC itself:

+---------+-----------------------------------+
| 0-3     | Version                           |
+---------+-----------------------------------+
| 4-11    | Volume name                       |
+---------+-----------------------------------+
| 12-13   | Number of partitions              |
+---------+-----------------------------------+
| 14-15   | Partition 1 type                  |
+---------+-----------------------------------+
| 16-17   | Partition 1 flags                 |
+---------+-----------------------------------+
| ...     | More partition types and flags    |
+---------+-----------------------------------+
| 42-45   | Partition 8 type and flags        |
+---------+-----------------------------------+
| 46-57   | Boot info                         |
+---------+-----------------------------------+
| 58-59   | Reserved                          |
+---------+-----------------------------------+
| 60-63   | Signature 0x600DDEEE              |
+---------+-----------------------------------+
| 64-101  | Reserved                          |
+---------+-----------------------------------+
| 102-105 | Partition 1 timestamp             |
+---------+-----------------------------------+
| ...     | More partition timestamps         |
+---------+-----------------------------------+
| 130-133 | Parittion 8 timestamp             |
+---------+-----------------------------------+

Partition types (informative):

0. unassigned
1. /boot
2. /
3. swap
4. /usr
5. entire disk
6. /stand
7. /var
8. /home
9. alternate sector
10. cachefs

Partition flags:

* 1 - Not mountable
* 128 - read only

Disk maps:

+-----+-------------------+
| 0-3 | Starting cylinder |
+-----+-------------------+
| 4-7 | Size (in sectors) |
+-----+-------------------+