Commit graph

2 commits

Author SHA1 Message Date
Arthur Heymans
0421ef2cd8 util/cbfstool: Add zstd support
This adds zstd support to cbfstool. The code is taken from zstd-1.5.7
with modifications:
- renaming bits.h to zstd_bits.h to avoid conflicts with coreboot's
  bits.h used on riscv
- renaming compiler.h to zstd_compiler.h to avoid conflicts with
  coreboot's compiler.h
- Dropped all streaming API functions
- Dropped multithreaded support, since it's now unused
- Dropped local DDict support

zstd offers similar compression ratios to LZMA, but a vastly fast
decompress speed. Typically zstd results in slightly larger binaries
than LZMA. Whether zstd should then be preferred over LZMA depends on
a few things:
- Caching: When loading from memory mapped boot devices, zstd will read
  the boot medium multiple times, while LZMA will not. If the memory
  mapped boot medium is not cached zstd results in much slower
  decompression.
- Boot medium speed: Often, but not always LZMA results in smaller
  binaries. If the boot medium is the bottleneck, than loading smaller
  binaries might actually be faster. On a fast boot medium (high spi
  freq, using quad/dual io), the performance benefits from zstd might be
  more substantial
- zstd decompression code has a much larger footprint than LZMA. If the
  stage (postcar) is loaded in uncached memory the size increase might
  slow things down.
  On QEMU Q35 postcar .text section size doubled, while heap section
  has growen by 50%.
- zstd uses a lot of .bss (CTX is about 32KiB large). This might not be
  available in some environments.

Orignal commit from 2022 was using zstd-1.5.2. Updated to zstd-1.5.7.

Change-Id: I34508268f8767008ef25cb9e466d201345881232
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69753
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2025-12-20 17:35:43 +00:00
Martin Roth
1f30b244b2 util: Rename Makefiles from .inc to .mk
The .inc suffix is confusing to various tools as it's not specific to
Makefiles. This means that editors don't recognize the files, and don't
open them with highlighting and any other specific editor functionality.

This issue is also seen in the release notes generation script where
Makefiles get renamed before running cloc.

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: I434940ebb46853980596f7ad55d27a62c90280fa
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80123
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
2024-01-26 12:43:18 +00:00
Renamed from util/cbfstool/Makefile.inc (Browse further)