mirror of
https://github.com/DarkFlippers/unleashed-firmware.git
synced 2024-12-23 21:34:35 +03:00
41c35cd59e
* Developers Docs editing * Logo underline removed The underline has been removed when hovering over the logo. * proofread docs * application -> app in several files --------- Co-authored-by: knrn64 <25254561+knrn64@users.noreply.github.com> Co-authored-by: あく <alleteam@gmail.com>
20 lines
1.0 KiB
Markdown
20 lines
1.0 KiB
Markdown
# Heatshrink-compressed Tarball Format {#heatshrink_file_format}
|
|
|
|
Flipper supports the use of Heatshrink compression library for `.tar` archives. This allows for smaller file sizes and faster OTA updates.
|
|
|
|
Heatshrink specification does not define a container format for storing compression parameters. This document describes the format used by Flipper to store Heatshrink-compressed data streams.
|
|
|
|
## Header
|
|
|
|
Header begins with a magic value, followed by a version number and compression parameters - window size and lookahead size.
|
|
|
|
Magic value consists of 4 bytes: `0x48 0x53 0x44 0x53` (ASCII "HSDS", HeatShrink DataStream).
|
|
|
|
Version number is a single byte, currently set to `0x01`.
|
|
|
|
Window size is a single byte, representing the size of the sliding window used by the compressor. It corresponds to `-w` parameter in Heatshrink CLI.
|
|
|
|
Lookahead size is a single byte, representing the size of the lookahead buffer used by the compressor. It corresponds to `-l` parameter in Heatshrink CLI.
|
|
|
|
Total header size is 7 bytes. Header is followed by compressed data.
|