spl: spl_legacy: Add lzma decompression support for legacy image

This patch adds support for decompressing LZMA compressed u-boot payload
in legacy uImage format.

Using this patch together with u-boot-lzma.img may be useful for some
platforms as they can reduce the size and load time of u-boot payload.

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>

diff --git a/common/spl/spl_legacy.c b/common/spl/spl_legacy.c
index 7f00fc88850998ead78b91e8b82e87d1906ef8c9..29d3ec70734dedefb2253ee39d1ef8732eed3d31 100644 (file)
--- a/common/spl/spl_legacy.c
+++ b/common/spl/spl_legacy.c
@@ -4,8 +4,15 @@
  */
 
 #include <common.h>
+#include <malloc.h>
 #include <spl.h>
 
+#include <lzma/LzmaTypes.h>
+#include <lzma/LzmaDec.h>
+#include <lzma/LzmaTools.h>
+
+#define LZMA_LEN       (1 << 20)
+
 int spl_parse_legacy_header(struct spl_image_info *spl_image,
                            const struct image_header *header)
 {
@@ -52,10 +59,27 @@ int spl_parse_legacy_header(struct spl_image_info *spl_image,
        return 0;
 }
 
+/*
+ * This function is added explicitly to avoid code size increase, when
+ * no compression method is enabled. The compiler will optimize the
+ * following switch/case statement in spl_load_legacy_img() away due to
+ * Dead Code Elimination.
+ */
+static inline int spl_image_get_comp(const struct image_header *hdr)
+{
+       if (IS_ENABLED(CONFIG_SPL_LZMA))
+               return image_get_comp(hdr);
+
+       return IH_COMP_NONE;
+}
+
 int spl_load_legacy_img(struct spl_image_info *spl_image,
                        struct spl_load_info *load, ulong header)
 {
+       __maybe_unused SizeT lzma_len;
+       __maybe_unused void *src;
        struct image_header hdr;
+       ulong dataptr;
        int ret;
 
        /* Read header into local struct */
@@ -65,9 +89,43 @@ int spl_load_legacy_img(struct spl_image_info *spl_image,
        if (ret)
                return ret;
 
+       dataptr = header + sizeof(hdr);
+
        /* Read image */
-       load->read(load, header + sizeof(hdr), spl_image->size,
-                  (void *)(unsigned long)spl_image->load_addr);
+       switch (spl_image_get_comp(&hdr)) {
+       case IH_COMP_NONE:
+               load->read(load, dataptr, spl_image->size,
+                          (void *)(unsigned long)spl_image->load_addr);
+               break;
+
+       case IH_COMP_LZMA:
+               lzma_len = LZMA_LEN;
+
+               debug("LZMA: Decompressing %08lx to %08lx\n",
+                     dataptr, spl_image->load_addr);
+               src = malloc(spl_image->size);
+               if (!src) {
+                       printf("Unable to allocate %d bytes for LZMA\n",
+                              spl_image->size);
+                       return -ENOMEM;
+               }
+
+               load->read(load, dataptr, spl_image->size, src);
+               ret = lzmaBuffToBuffDecompress((void *)spl_image->load_addr,
+                                              &lzma_len, src, spl_image->size);
+               if (ret) {
+                       printf("LZMA decompression error: %d\n", ret);
+                       return ret;
+               }
+
+               spl_image->size = lzma_len;
+               break;
+
+       default:
+               debug("Compression method %s is not supported\n",
+                     genimg_get_comp_short_name(image_get_comp(&hdr)));
+               return -EINVAL;
+       }
 
        return 0;
 }