ExeFS

Overview

ExeFS or Executable Filesystem, is the part of the CXI, which is executed when the CXI is run.

The ExeFS usually contains one or more of the following files:

• .code Contains the code binary, which can be optionally reverse-LZSS compressed via an exheader flag.
• .logo Contains distribution licensing Binary data.
• .banner Contains the banner which homemenu uses for this CXI.
• .icon Contains the icon which homemenu displays for this CXI.

Format

The ExeFS header is 0x200 bytes long and follows this simple structure:

START	SIZE	DESCRIPTION
0x00	0x80	File headers (8 headers maximum, 16 bytes each)
0x80	0x80	Reserved
0x100	0x100	File hashes (8 hashes maximum, 32 bytes each, one for each header)

File headers

There are a maximum of 8 file headers in the ExeFS format, which have the following structure:

START	SIZE	DESCRIPTION
0x0	0x8	File name
0x8	0x4	File offset
0xC	0x4	File size

File hashes

Each file header has a corresponding file hash, which is the SHA256 hash calculated over the entire file contents.

* Offsets are non-inclusive of the header's size(0x200 bytes).

** The 'Logo' is not a compulsory part of ExeFS, so an ExeFS without a 'Logo', will have these entries of the header filled with zeros. .