[U-Boot] [PATCH v2 1/2] image: android: allow booting lz4-compressed kernels

[Eugeniu Rosca]

Hello,

I've got some valuable feedback from Roman (cc:) that the magic numbers
of the legacy and the newer LZ4 formats do not match, hence with the
current patch U-Boot would try to handle the legacy "lz4 -l"-compressed
kernel as a raw/uncompressed image.

Since U-Boot itself supports only the newer lz4 format [1], apparently
the best we can do is detect the legacy lz4 format and report it is
unsupported. If no comments, this will be taken care of in v3.

[1] Quote from https://github.com/trini/u-boot/commit/027b728d4aafb5cf97abc804944a77b837b0f07f#diff-df7190887ae0d38ba3f64a4c494d25c0R113
    NOTE: This implements the release version of the LZ4 frame
    format as generated by default by the 'lz4' command line tool.
    This is not the same as the outdated, less efficient legacy
    frame format currently (2015) implemented in the Linux kernel
    (generated by 'lz4 -l'). The two formats are incompatible.

Best regards,
Eugeniu.