From 09f2921b5dacaf79b391652cecd606be4dd69f50 Mon Sep 17 00:00:00 2001 From: Julius Werner 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 Reviewed-on: https://review.coreboot.org/13638 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin --- util/cbfstool/compress.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'util/cbfstool/compress.c') diff --git a/util/cbfstool/compress.c b/util/cbfstool/compress.c index 51353317f4..a6a0df4dd1 100644 --- a/util/cbfstool/compress.c +++ b/util/cbfstool/compress.c @@ -20,7 +20,42 @@ #include #include +#include #include "common.h" +#include "lz4/lib/lz4frame.h" +#include + +static int lz4_compress(char *in, int in_len, char *out, int *out_len) +{ + LZ4F_preferences_t prefs = { + .compressionLevel = 20, + .frameInfo = { + .blockSizeID = max4MB, + .blockMode = blockIndependent, + .contentChecksumFlag = noContentChecksum, + }, + }; + size_t worst_size = LZ4F_compressFrameBound(in_len, &prefs); + void *bounce = malloc(worst_size); + if (!bounce) + return -1; + *out_len = LZ4F_compressFrame(bounce, worst_size, in, in_len, &prefs); + if (LZ4F_isError(*out_len) || *out_len >= in_len) + return -1; + memcpy(out, bounce, *out_len); + return 0; +} + +static int lz4_decompress(char *in, int in_len, char *out, int out_len, + size_t *actual_size) +{ + size_t result = ulz4fn(in, in_len, out, out_len); + if (result == 0) + return -1; + if (actual_size != NULL) + *actual_size = result; + return 0; +} static int lzma_compress(char *in, int in_len, char *out, int *out_len) { @@ -58,6 +93,9 @@ comp_func_ptr compression_function(enum comp_algo algo) case CBFS_COMPRESS_LZMA: compress = lzma_compress; break; + case CBFS_COMPRESS_LZ4: + compress = lz4_compress; + break; default: ERROR("Unknown compression algorithm %d!\n", algo); return NULL; @@ -75,6 +113,9 @@ decomp_func_ptr decompression_function(enum comp_algo algo) case CBFS_COMPRESS_LZMA: decompress = lzma_decompress; break; + case CBFS_COMPRESS_LZ4: + decompress = lz4_decompress; + break; default: ERROR("Unknown compression algorithm %d!\n", algo); return NULL; -- cgit v1.2.3