binman: Add gzip bintool

Add gzip bintool to binman to support on-the-fly compression of Linux
kernel images and FPGA bitstreams. The SPL basic fitImage implementation
supports only gzip decompression.

Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Rename the module and support this, since gzip.py is a system module:
Signed-off-by: Simon Glass <sjg@chromium.org>

tools/binman/btool/btool_gzip.py

@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Copyright (C) 2022 Weidmüller Interface GmbH & Co. KG
+# Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
+#
+"""Bintool implementation for gzip
+
+gzip allows compression and decompression of files.
+
+Documentation is available via::
+
+   man gzip
+"""
+
+from binman import bintool
+
+# pylint: disable=C0103
+class Bintoolbtool_gzip(bintool.BintoolPacker):
+    """Compression/decompression using the gzip algorithm
+
+    This bintool supports running `gzip` to compress and decompress data, as
+    used by binman.
+
+    It is also possible to fetch the tool, which uses `apt` to install it.
+
+    Documentation is available via::
+
+        man gzip
+    """
+    def __init__(self, name):
+        super().__init__(name, compress_args=[],
+                         version_regex=r'gzip ([0-9.]+)')