1 files changed, 44 insertions, 1 deletions

diff --git a/scripts/runqemu b/scripts/runqemu
index 3d77046972..c668906bdd 100755
--- a/scripts/runqemu
+++ b/scripts/runqemu
@@ -197,7 +197,7 @@ class BaseConfig(object):
         self.portlocks = {}
         self.bitbake_e = ''
         self.snapshot = False
-        self.wictypes = ('wic', 'wic.vmdk', 'wic.qcow2', 'wic.vdi', "wic.vhd", "wic.vhdx")
+        self.wictypes = ('wic.zst', 'wic', 'wic.vmdk', 'wic.qcow2', 'wic.vdi', "wic.vhd", "wic.vhdx")
         self.fstypes = ('ext2', 'ext3', 'ext4', 'jffs2', 'nfs', 'btrfs',
                         'cpio.gz', 'cpio', 'ramfs', 'tar.bz2', 'tar.gz',
                         'squashfs', 'squashfs-xz', 'squashfs-lzo',
@@ -418,6 +418,48 @@ class BaseConfig(object):
         else:
             raise RunQemuError("Unknown path arg %s" % p)
 
+    def uncompress_rootfs(self):
+        """Decompress ZST rootfs image if needed"""
+        if not self.rootfs or not self.fstype.endswith('.zst'):
+            return
+        
+        # Ensure snapshot mode is active before allowing decompression.
+        if not self.snapshot:
+            raise RunQemuError(".zst images are only supported with snapshot mode. " \
+                                "You can either use the \"snapshot\" option or use an uncompressed image.")
+        
+        # Get the real path to the image to avoid issues when a symbolic link is passed.
+        # This ensures we always operate on the actual file.
+        image_path = os.path.realpath(self.rootfs)
+        # Extract target filename by removing .zst
+        image_dir = os.path.dirname(image_path)
+        uncompressed_name = os.path.basename(image_path).replace(".zst", "")
+        uncompressed_path = os.path.join(image_dir, uncompressed_name)
+    
+        # If the decompressed image already exists (e.g., in the deploy directory),
+        # we use it directly to avoid overwriting artifacts generated by the build system.
+        # This prevents redundant decompression and preserves build outputs.
+        if os.path.exists(uncompressed_path):
+            logger.warning(f"Found existing decompressed image: {uncompressed_path}, Using it directly.")
+        else:
+            logger.info(f"Decompressing {self.rootfs} to {uncompressed_path}")
+            # Ensure the 'zstd' tool is installed before attempting to decompress.
+            if not shutil.which('zstd'):
+                raise RunQemuError(f"'zstd' is required to decompress {self.rootfs} but was not found in PATH")
+            try:
+                with open(uncompressed_path, 'wb') as out_file:
+                    subprocess.check_call(['zstd', '-d', '-c', image_path], stdout=out_file)
+            except subprocess.CalledProcessError as e:
+                self.cleanup_files.append(uncompressed_path)
+                raise RunQemuError(f"Failed to decompress {self.rootfs}: {e}")
+    
+            # Mark for deletion at the end
+            self.cleanup_files.append(uncompressed_path)
+    
+        # Use the decompressed image as the rootfs
+        self.rootfs = uncompressed_path
+        self.fstype = self.fstype.removesuffix(".zst")
+
     def check_arg_machine(self, arg):
         """Check whether it is a machine"""
         if self.get('MACHINE') == arg:
@@ -1762,6 +1804,7 @@ def main():
         config.check_args()
         config.read_qemuboot()
         config.check_and_set()
+        config.uncompress_rootfs()
         # Check whether the combos is valid or not
         config.validate_combos()
         config.print_config()