cbfstool: add decompression wrappers

... and document the interface.

Change-Id: I86a071a61fd6c1ef842f8ffe51f12f0cefdaf2fe
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/11362
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)

2 files changed, 42 insertions, 1 deletions

diff --git a/util/cbfstool/common.h b/util/cbfstool/common.h
index 5fb19065dfc9..4a97fed6cb45 100644
--- a/util/cbfstool/common.h
+++ b/util/cbfstool/common.h
@@ -146,10 +146,24 @@ void buffer_delete(struct buffer *buffer);
 const char *arch_to_string(uint32_t a);
 uint32_t string_to_arch(const char *arch_string);
 
-typedef int (*comp_func_ptr) (char *, int, char *, int *);
+/* Compress in_len bytes from in, storing the result at out, returning the
+ * resulting length in out_len.
+ * Returns 0 on error,
+ *         != 0 otherwise, depending on the compressing function.
+ */
+typedef int (*comp_func_ptr) (char *in, int in_len, char *out, int *out_len);
+
+/* Decompress in_len bytes from in, storing the result at out, up to out_len
+ * bytes.
+ * Returns 0 on error,
+ *         != 0 otherwise, depending on the decompressing function.
+ */
+typedef int (*decomp_func_ptr) (char *in, int in_len, char *out, int out_len);
+
 enum comp_algo { CBFS_COMPRESS_NONE = 0, CBFS_COMPRESS_LZMA = 1 };
 
 comp_func_ptr compression_function(enum comp_algo algo);
+decomp_func_ptr decompression_function(enum comp_algo algo);
 
 uint64_t intfiletype(const char *name);
 
diff --git a/util/cbfstool/compress.c b/util/cbfstool/compress.c
index ab94b353290c..2bde7df96adb 100644
--- a/util/cbfstool/compress.c
+++ b/util/cbfstool/compress.c
@@ -31,6 +31,10 @@ static int lzma_compress(char *in, int in_len, char *out, int *out_len)
 	return do_lzma_compress(in, in_len, out, out_len);
 }
 
+static int lzma_decompress(char *in, int in_len, char *out, unused int out_len)
+{
+	return do_lzma_uncompress(out, out_len, in, in_len);
+}
 static int none_compress(char *in, int in_len, char *out, int *out_len)
 {
 	memcpy(out, in, in_len);
@@ -38,6 +42,12 @@ static int none_compress(char *in, int in_len, char *out, int *out_len)
 	return 0;
 }
 
+static int none_decompress(char *in, int in_len, char *out, unused int out_len)
+{
+	memcpy(out, in, in_len);
+	return 0;
+}
+
 comp_func_ptr compression_function(enum comp_algo algo)
 {
 	comp_func_ptr compress;
@@ -54,3 +64,20 @@ comp_func_ptr compression_function(enum comp_algo algo)
 	}
 	return compress;
 }
+
+decomp_func_ptr decompression_function(enum comp_algo algo)
+{
+	decomp_func_ptr decompress;
+	switch (algo) {
+	case CBFS_COMPRESS_NONE:
+		decompress = none_decompress;
+		break;
+	case CBFS_COMPRESS_LZMA:
+		decompress = lzma_decompress;
+		break;
+	default:
+		ERROR("Unknown compression algorithm %d!\n", algo);
+		return NULL;
+	}
+	return decompress;
+}