FSS0 Extractor

A simple python script to extract the contents out of Fusée Secondary binary file.

Usage

fss0-extractor.py [-h] input output

positional arguments:
  input       Location of the fusee-secondary.bin file.
  output      Location to extract files

optional arguments:
  -h, --help  show this help message and exit

FSS0 File Structure

Offset	Size	Description
0x0	0x4	Instruction to branch to startup code
0x4	0x4	Offset of header
0x8		Startup code

Header

Offset	Size	Description
0x0	0x4	Magicnum "FSS0"
0x4	0x4	Size of the entire file
0x8	0x4	Offset of startup code
0xC	0x4	Offset of content headers
0x10	0x4	Number of content headers
0x14	0x4	Maximum Horizon OS Supported
0x18	0x4	Atmosphere Version
0x1C	0x4	First four bytes of the git revision

Content Header

Offset	Size	Description
0x0	0x4	Offset of content
0x4	0x4	Size of content
0x8	0x1	Type
0x9	0x1	First flag
0xA	0x1	Second flag
0xB	0x1	Third flag
0xC	0x4	Reserved
0x10	0x10	Name

Content Header Types

Value	Description
0x0	Fusee Primary
0x1	Exosphere
0x2	LP0 Firmware
0x3	Reboot Stub
0x4	Sept Primary
0x5	Sept Secondary
0x6	KIP
0x7	Bitmap
0x8	EmuMMC
0x9	Kernel Loader
0xA	Kernel

Content Header Flags

Value	Description
0x0	None
0x1	Experimental