Re: [RFC-PATCH-for-11.0] loader: Add support for U-Boot Zstandard-compressed image

[Philippe Mathieu-Daudé]

On 24/11/25 13:22, Philippe Mathieu-Daudé wrote:

U-Boot is able to decompress Zstandard images since almost
6 years (u-boot commit 8509f22a).

Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
---
Based-on: <20251011081553.4065883-1-daan.j.deme...@gmail.com>

Same patch applies on Daan's v4:
Based-on: <20251124123521.1058183-1-daan.j.deme...@gmail.com>

---
  hw/core/loader.c | 22 ++++++++++++++++++----
  1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index e5904cdafa1..97fa8248ce7 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -635,7 +635,7 @@ static ssize_t load_uboot_image(const char *filename, 
hwaddr *ep,
      uboot_image_header_t *hdr = &h;
      uint8_t *data = NULL;
      int ret = -1;
-    int do_uncompress = 0;
+    bool do_uncompress = false;

fd = open(filename, O_RDONLY | O_BINARY);

      if (fd < 0)
@@ -685,7 +685,8 @@ static ssize_t load_uboot_image(const char *filename, 
hwaddr *ep,
          case IH_COMP_NONE:
              break;
          case IH_COMP_GZIP:
-            do_uncompress = 1;
+        case IH_COMP_ZSTD:
+            do_uncompress = true;
              break;
          default:
              fprintf(stderr,
@@ -747,10 +748,23 @@ static ssize_t load_uboot_image(const char *filename, 
hwaddr *ep,
          max_bytes = UBOOT_MAX_GUNZIP_BYTES;
          data = g_malloc(max_bytes);

- bytes = gunzip(data, max_bytes, compressed_data, hdr->ih_size);

+        switch (hdr->ih_comp) {
+        case IH_COMP_GZIP:
+            bytes = gunzip(data, max_bytes, compressed_data, hdr->ih_size);
+            break;
+#ifdef CONFIG_ZSTD
+        case IH_COMP_ZSTD: {
+            size_t ret = ZSTD_decompress(data, max_bytes,
+                                         compressed_data, hdr->ih_size);
+            bytes = ZSTD_isError(ret) ? -1 : (ssize_t) ret;
+            } break;
+#endif
+        default:
+            g_assert_not_reached();
+        }
          g_free(compressed_data);
          if (bytes < 0) {
-            fprintf(stderr, "Unable to decompress gzipped image!\n");
+            fprintf(stderr, "Unable to decompress image!\n");
              goto out;
          }
          hdr->ih_size = bytes;