CBFS: Change the signature of cbfs_decompress.

Instead of returning 0 on success and -1 on error, return the decompressed
size of the data on success and 0 on error. The decompressed size is useful
information to have that was being thrown away in that function.

Change-Id: If787201aa61456b1e47feaf3a0071c753fa299a3
Signed-off-by: Gabe Black <gabeblack@chromium.org>
Reviewed-on: http://review.coreboot.org/3578
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

4 files changed, 18 insertions, 19 deletions

diff --git a/src/include/cbfs_core.h b/src/include/cbfs_core.h
index 54e2f60d87..08fe8150ed 100644
--- a/src/include/cbfs_core.h
+++ b/src/include/cbfs_core.h
@@ -218,7 +218,7 @@ struct cbfs_file *cbfs_get_file(struct cbfs_media *media, const char *name);
 void *cbfs_get_file_content(struct cbfs_media *media, const char *name,
 			    int type);
 
-/* returns 0 on success, -1 on failure */
+/* returns decompressed size on success, 0 on failure */
 int cbfs_decompress(int algo, void *src, void *dst, int len);
 
 /* returns a pointer to CBFS master header, or CBFS_HEADER_INVALID_ADDRESS
diff --git a/src/lib/cbfs.c b/src/lib/cbfs.c
index aba1bcccf0..400b8a5f9d 100644
--- a/src/lib/cbfs.c
+++ b/src/lib/cbfs.c
@@ -112,7 +112,7 @@ void *cbfs_load_optionrom(struct cbfs_media *media, uint16_t vendor,
 	if (! dest)
 		return src;
 
-	if (cbfs_decompress(ntohl(orom->compression),
+	if (!cbfs_decompress(ntohl(orom->compression),
 			     src,
 			     dest,
 			     ntohl(orom->len)))
@@ -204,8 +204,8 @@ static void *load_stage_from_cbfs(struct cbfs_media *media, const char *name,
 	LOG("Decompressing stage %s @ 0x%p (%d bytes)\n",
 	    name, &ramstage_region[rmodule_offset], stage->memlen);
 
-	if (cbfs_decompress(stage->compression, &stage[1],
-	                    &ramstage_region[rmodule_offset], stage->len))
+	if (!cbfs_decompress(stage->compression, &stage[1],
+	                     &ramstage_region[rmodule_offset], stage->len))
 		return (void *) -1;
 
 	if (rmodule_parse(&ramstage_region[rmodule_offset], &ramstage))
@@ -259,6 +259,7 @@ void * cbfs_load_stage(struct cbfs_media *media, const char *name)
 	/* this is a mess. There is no ntohll. */
 	/* for now, assume compatible byte order until we solve this. */
 	uint32_t entry;
+	uint32_t final_size;
 
 	if (stage == NULL)
 		return (void *) -1;
@@ -270,11 +271,12 @@ void * cbfs_load_stage(struct cbfs_media *media, const char *name)
 	/* Stages rely the below clearing so that the bss is initialized. */
 	memset((void *) (uint32_t) stage->load, 0, stage->memlen);
 
-	if (cbfs_decompress(stage->compression,
-			     ((unsigned char *) stage) +
-			     sizeof(struct cbfs_stage),
-			     (void *) (uint32_t) stage->load,
-			     stage->len))
+	final_size = cbfs_decompress(stage->compression,
+				     ((unsigned char *) stage) +
+				     sizeof(struct cbfs_stage),
+				     (void *) (uint32_t) stage->load,
+				     stage->len);
+	if (!final_size)
 		return (void *) -1;
 
 	DEBUG("stage loaded.\n");
diff --git a/src/lib/cbfs_core.c b/src/lib/cbfs_core.c
index 39c1ff6008..612fef2a6f 100644
--- a/src/lib/cbfs_core.c
+++ b/src/lib/cbfs_core.c
@@ -196,19 +196,16 @@ int cbfs_decompress(int algo, void *src, void *dst, int len)
 	switch (algo) {
 		case CBFS_COMPRESS_NONE:
 			memmove(dst, src, len);
-			return 0;
+			return len;
 #ifdef CBFS_CORE_WITH_LZMA
 		case CBFS_COMPRESS_LZMA:
-			if (ulzma(src, dst) != 0) {
-				return 0;
-			}
-			return -1;
+			return ulzma(src, dst);
 #endif
 		default:
 			ERROR("tried to decompress %d bytes with algorithm #%x,"
 			      "but that algorithm id is unsupported.\n", len,
 			      algo);
-			return -1;
+			return 0;
 	}
 }
 
diff --git a/src/vendorcode/google/chromeos/vboot_loader.c b/src/vendorcode/google/chromeos/vboot_loader.c
index 10fa52d698..b627af6d3f 100644
--- a/src/vendorcode/google/chromeos/vboot_loader.c
+++ b/src/vendorcode/google/chromeos/vboot_loader.c
@@ -66,8 +66,8 @@ static void vboot_run_stub(struct vboot_context *context)
 
 	vboot_region = cbmem_entry_start(vboot_entry);
 
-	if (cbfs_decompress(stage->compression, &stage[1],
-	                    &vboot_region[rmodule_offset], stage->len)) {
+	if (!cbfs_decompress(stage->compression, &stage[1],
+	                     &vboot_region[rmodule_offset], stage->len)) {
 		printk(BIOS_DEBUG, "Couldn't decompress vboot stub.\n");
 		goto out;
 	}
@@ -221,8 +221,8 @@ static void vboot_load_ramstage(struct vboot_handoff *vboot_handoff,
 	printk(BIOS_DEBUG, "Decompressing ramstage @ 0x%p (%d bytes)\n",
 	       &ramstage_region[rmodule_offset], stage->memlen);
 
-	if (cbfs_decompress(stage->compression, &stage[1],
-	                    &ramstage_region[rmodule_offset], stage->len))
+	if (!cbfs_decompress(stage->compression, &stage[1],
+	                     &ramstage_region[rmodule_offset], stage->len))
 		return;
 
 	if (rmodule_parse(&ramstage_region[rmodule_offset], &ramstage))