Firmware format

Overview

The firmware file is made up of the following components:

Component	Size description	Example	Description
Firmware header	Defined at offset 0x0050	0x00000080 (128 bytes)
Module headers	Module header size (defined at offset 0x0054), multiplied by number of modules (defined at offset 0x007C)	0x00000040 (64 bytes) * 0x0000004F (79 modules) = 0x000013C0 (5056 bytes)
Data	TBC

Firmware header

The firmware header is located at the very beginning of the file. Its length is defined by the 32 bit unsigned integer (big endian) located at offset 0x0050. For example: 0x00000080 (128 bytes).

The format for the firmware header is described below:

Size (byte)	Type	Description	Example
16	Byte array	Identifier	SkOsMo5 fIrMwArE
32	Byte array	Signature	Not used
16	Byte array	MD5 of firmware header + module headers	90 2D F5 21 17 F8 1F E7 8B 4D 68 27 CC B1 87 A4
16	Byte array	A random sequence	8C 6C D4 ED 19 B2 74 E9 3E 49 AD EB F6 55 01 A3
4	Unsigned BE Int	Length of the entire firmware header	0x00000080 (128 bytes)
4	Unsigned BE Int	Length of each module header	0x00000040 (64 bytes)
4	Unsigned BE Int	Length of entire file	0x0043153D (4396349 bytes)
32	Byte array	Firmware viersion number	7.6.2f
4	Unsigned BE Int	Number of modules present in the firmware	0x0000004F (79 modules)

Module headers

There are likely multiple modules in the firmware file. The number of modules is defined at offset 0x007C in the firmware header. For example: 0x0000004F (79 modules).

Each module has a module header. These are of a length defined at offset 0x0054 in the firmware header. For example: 0x00000040 (64 bytes). Each module header is concatenated in order, directly after the firmware header (in this case, from offset 0x0080).