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authorJulius Werner <jwerner@chromium.org>2015-09-29 13:51:35 -0700
committerJulius Werner <jwerner@chromium.org>2016-02-22 21:38:37 +0100
commit09f2921b5dacaf79b391652cecd606be4dd69f50 (patch)
tree581236de48a22240cb1b823195a79493f037fb64 /src/include
parent0e3d7de7410c4ff7c9465261b58524675a0329e2 (diff)
downloadcoreboot-09f2921b5dacaf79b391652cecd606be4dd69f50.tar.xz
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>
Diffstat (limited to 'src/include')
-rw-r--r--src/include/cbfs.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/src/include/cbfs.h b/src/include/cbfs.h
index 0d95387940..2d1921898a 100644
--- a/src/include/cbfs.h
+++ b/src/include/cbfs.h
@@ -35,6 +35,14 @@ int cbfs_boot_locate(struct cbfsf *fh, const char *name, uint32_t *type);
* the mapping and sets the size of the file. */
void *cbfs_boot_map_with_leak(const char *name, uint32_t type, size_t *size);
+/* Load |in_size| bytes from |rdev| at |offset| to the |buffer_size| bytes
+ * large |buffer|, decompressing it according to |compression| in the process.
+ * Returns the decompressed file size, or 0 on error.
+ * LZMA files will be mapped for decompression. LZ4 files will be decompressed
+ * in-place with the buffer size requirements outlined in compression.h. */
+size_t cbfs_load_and_decompress(const struct region_device *rdev, size_t offset,
+ size_t in_size, void *buffer, size_t buffer_size, uint32_t compression);
+
/* Load stage into memory filling in prog. Return 0 on success. < 0 on error. */
int cbfs_prog_stage_load(struct prog *prog);