lib/cbfs: add cbfs_stage_load_and_decompress helper
The LZ4 compressed stages assume in-place decompression. The constraints
are validated in cbfstool for _stages_ such that they can be decompressed
in place. However, that is only true for stages. As such, add a wrapper,
cbfs_stage_load_and_decompress(), that handles the LZ4 stage loading case.
BUG=b:155322763,b:150746858,b:152909132
Change-Id: I9525a266250aa6c775283b598c09d4f40692db55
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41755
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/lib/cbfs.c b/src/lib/cbfs.c
index 74df3c5..e05ea80 100644
--- a/src/lib/cbfs.c
+++ b/src/lib/cbfs.c
@@ -116,6 +116,7 @@
size_t in_size, void *buffer, size_t buffer_size, uint32_t compression)
{
size_t out_size;
+ void *map;
switch (compression) {
case CBFS_COMPRESS_NONE:
@@ -129,23 +130,24 @@
if (!cbfs_lz4_enabled())
return 0;
- /* Load the compressed image to the end of the available memory
- * area for in-place decompression. It is the responsibility of
- * the caller to ensure that buffer_size is large enough
- * (see compression.h, guaranteed by cbfstool for stages). */
- void *compr_start = buffer + buffer_size - in_size;
- if (rdev_readat(rdev, compr_start, offset, in_size) != in_size)
+ /* cbfs_stage_load_and_decompress() takes care of in-place
+ lz4 decompression by setting up the rdev to be in memory. */
+ map = rdev_mmap(rdev, offset, in_size);
+ if (map == NULL)
return 0;
timestamp_add_now(TS_START_ULZ4F);
- out_size = ulz4fn(compr_start, in_size, buffer, buffer_size);
+ out_size = ulz4fn(map, in_size, buffer, buffer_size);
timestamp_add_now(TS_END_ULZ4F);
+
+ rdev_munmap(rdev, map);
+
return out_size;
case CBFS_COMPRESS_LZMA:
if (!cbfs_lzma_enabled())
return 0;
- void *map = rdev_mmap(rdev, offset, in_size);
+ map = rdev_mmap(rdev, offset, in_size);
if (map == NULL)
return 0;
@@ -163,6 +165,35 @@
}
}
+static size_t cbfs_stage_load_and_decompress(const struct region_device *rdev,
+ size_t offset, size_t in_size, void *buffer, size_t buffer_size,
+ uint32_t compression)
+{
+ struct region_device rdev_src;
+
+ if (compression == CBFS_COMPRESS_LZ4) {
+ if (!cbfs_lz4_enabled())
+ return 0;
+ /* Load the compressed image to the end of the available memory
+ * area for in-place decompression. It is the responsibility of
+ * the caller to ensure that buffer_size is large enough
+ * (see compression.h, guaranteed by cbfstool for stages). */
+ void *compr_start = buffer + buffer_size - in_size;
+ if (rdev_readat(rdev, compr_start, offset, in_size) != in_size)
+ return 0;
+ /* Create a region device backed by memory. */
+ rdev_chain(&rdev_src, &addrspace_32bit.rdev,
+ (uintptr_t)compr_start, in_size);
+
+ return cbfs_load_and_decompress(&rdev_src, 0, in_size, buffer,
+ buffer_size, compression);
+ }
+
+ /* All other algorithms can use the generic implementation. */
+ return cbfs_load_and_decompress(rdev, offset, in_size, buffer,
+ buffer_size, compression);
+}
+
static inline int tohex4(unsigned int c)
{
return (c <= 9) ? (c + '0') : (c - 10 + 'a');
@@ -257,7 +288,7 @@
goto out;
}
- fsize = cbfs_load_and_decompress(fh, foffset, fsize, load,
+ fsize = cbfs_stage_load_and_decompress(fh, foffset, fsize, load,
stage.memlen, stage.compression);
if (!fsize)
return -1;