Packing_lgapp_partition - openlgtv/wiki GitHub Wiki

LGAPP partition is CramFS Linear XIP (eXecuted In Place) image packed with modified LZO.

LZO

LZO algorythm modification made by LG quite simple. They extended magic from 1 byte with 0x00 and following 32 bits is size of uncompressed image. Thus making the famous 5 bytes differing from standard lzo.

Arno moded lzo-2.03 lzopack example and it now decompress and recompress the "LG way". Sources and binary can be found at http://lgmod.free.fr/tools/lgapp/

CramFS Linear XIP

Patched mkcramfs utility to make linear zip images: source, binary, original patch

Before make cramfs, XIP files in Linear XIP CramFS image should be marked with +t, to store it uncompressed and page-aligned.