the following patch was just integrated into master: commit bf27391da5b12f53444a9e678bcfb912f88e30e4 Author: Julius Werner jwerner@chromium.org Date: Tue Jun 30 10:30:30 2015 -0700
libpayload: Add LZ4 decompression algorithm
This patch adds support for the LZ4 decompression algorithm to libpayload. It's what all the cool kids are using for decompression these days and has many interesting advantages over LZMA (and everything else I know of): blazing fast decompression (20(!) times faster than LZMA, twice as fast as LZO on my Cortex-A72), no memory requirements on decompression, and possibly in-place decompression support. It pays for that with a lower compression ratio (about 50% larger compressed size than LZMA, 10% larger than LZO for an ARM64 Linux kernel binary), but the boot time math still works in its favor for our IO speeds.
This patch only adds the raw decompression functions for use by external payloads, we can later try integrating them in CBFS. It copies the decompression code itself unmodified from the upstream LZ4 library at github.com/Cyan4973/lz4 which will hopefully make it easy to update. The frame format parsing is reimplemented since the upstream version looks unnecessarily complex and unreadable for our needs.
BRANCH=smaug BUG=chrome-os-partner:32184 TEST=With other patches, booted ARM64 kernel that got compressed from 15M to 5.1M and decompresses in 44ms.
Change-Id: I65bdc4b2b19bd51c7b7e17a4e4b79da301a2a014 Signed-off-by: Patrick Georgi pgeorgi@chromium.org Original-Commit-Id: f8a1fc996d5b0234d07f567fa8163d0f802d5144 Original-Change-Id: I15c0620da05561ade2552b15ffdf6bb3afd7eb26 Original-Signed-off-by: Julius Werner jwerner@chromium.org Original-Reviewed-on: https://chromium-review.googlesource.com/282743 Original-Reviewed-by: Stefan Reinauer reinauer@google.com Original-Reviewed-by: Aaron Durbin adurbin@chromium.org Reviewed-on: http://review.coreboot.org/10845 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer stefan.reinauer@coreboot.org
See http://review.coreboot.org/10845 for details.
-gerrit