From 09f2921b5dacaf79b391652cecd606be4dd69f50 Mon Sep 17 00:00:00 2001 From: Julius Werner <jwerner@chromium.org> Date: Tue, 29 Sep 2015 13:51:35 -0700 Subject: cbfs: Add LZ4 in-place decompression support for pre-RAM stages This patch ports the LZ4 decompression code that debuted in libpayload last year to coreboot for use in CBFS stages (upgrading the base algorithm to LZ4's dev branch to access the new in-place decompression checks). This is especially useful for pre-RAM stages in constrained SRAM-based systems, which previously could not be compressed due to the size requirements of the LZMA scratchpad and bounce buffer. The LZ4 algorithm offers a very lean decompressor function and in-place decompression support to achieve roughly the same boot speed gains (trading compression ratio for decompression time) with nearly no memory overhead. For now we only activate it for the stages that had previously not been compressed at all on non-XIP (read: non-x86) boards. In the future we may also consider replacing LZMA completely for certain boards, since which algorithm wins out on boot speed depends on board-specific parameters (architecture, processor speed, SPI transfer rate, etc.). BRANCH=None BUG=None TEST=Built and booted Oak, Jerry, Nyan and Falco. Measured boot time on Oak to be about ~20ms faster (cutting load times for affected stages almost in half). Change-Id: Iec256c0e6d585d1b69985461939884a54e3ab900 Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://review.coreboot.org/13638 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin <adurbin@chromium.org> --- src/vendorcode/google/chromeos/vboot2/Makefile.inc | 1 + 1 file changed, 1 insertion(+) (limited to 'src/vendorcode/google/chromeos') diff --git a/src/vendorcode/google/chromeos/vboot2/Makefile.inc b/src/vendorcode/google/chromeos/vboot2/Makefile.inc index 61cf71df5a..2ca8a1adc3 100644 --- a/src/vendorcode/google/chromeos/vboot2/Makefile.inc +++ b/src/vendorcode/google/chromeos/vboot2/Makefile.inc @@ -72,6 +72,7 @@ ifeq ($(CONFIG_SEPARATE_VERSTAGE),y) cbfs-files-$(CONFIG_SEPARATE_VERSTAGE) += $(CONFIG_CBFS_PREFIX)/verstage $(CONFIG_CBFS_PREFIX)/verstage-file := $(objcbfs)/verstage.elf $(CONFIG_CBFS_PREFIX)/verstage-type := stage +$(CONFIG_CBFS_PREFIX)/verstage-compression := $(CBFS_PRERAM_COMPRESS_FLAG) # Verstage on x86 expected to be xip. ifeq ($(CONFIG_ARCH_VERSTAGE_X86_32)$(CONFIG_ARCH_VERSTAGE_X86_64),y) $(CONFIG_CBFS_PREFIX)/verstage-options := -a 64 --xip -S ".car.data" -- cgit v1.2.3