From e069fe2480c871c649b83f6278564a553cc3dd58 Mon Sep 17 00:00:00 2001 From: Lamine REHAHLIA Date: Thu, 31 Jul 2025 17:33:10 +0200 Subject: [PATCH] runqemu: Add support for running compressed .zst rootfs images Enhance runqemu to detect and decompress .zst-compressed rootfs images (e.g. ext4.zst, wic.zst) automatically. If a decompressed image already exists in the original directory, it will be reused to avoid overwriting build artifacts. Otherwise, the image is decompressed and removed after the QEMU session ends. This allows runqemu to be used seamlessly with compressed image formats generated by the build system or during releases. Note: support for .zst images is only available when snapshot mode is enabled IMPORTANT: This patch assumes that the original directory of the .zst-compressed image is writable. If, for some reason, the path passed from CI or another system to the script is read-only, the decompression step will fail when trying to write the uncompressed image to the same directory. Signed-off-by: Lamine REHAHLIA Signed-off-by: Yoann Congal Signed-off-by: Richard Purdie --- scripts/runqemu | 45 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 44 insertions(+), 1 deletion(-) 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() -- 2.47.2