Add support for releasing deblobbed u-boot 2020.07 source tarballs

Once the tarball are released, it will enable distributions to use
these tarballs to produce deblobbed u-boot packages.

Note that the produced tarball is not reproducible yet. Because of
that it has to be trusted.

During a release, it's a good idea to sign the uncompressed tarball as
the various compression formats and associated tools make different
tradeoffs.

For instance with xz, xz -9e tends to compress really well with the
the most used xz[1] implementation, and most GNU/Linux users probably
already have it installed, but and the drawbacks is that the format is
very fragile[2].

The lzip format is more suited for long term archiving but its most
packaged implementation[3] is less likely to be already installed by
users than more well known formats like xz, bzip2 or gzip.

Being able to add more compression formats after the release is also
useful, for instance to accommodate different build systems or use
cases (like being able to build u-boot with less dependencies in
distributions like Guix, or building u-boot directly on devices which
don't have enough RAM for xz for instance).

[1]https://tukaani.org/xz/
[2]https://www.nongnu.org/lzip/xz_inadequate.html
[3]https://www.nongnu.org/lzip/

Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>

1 files changed, 123 insertions, 0 deletions

diff --git a/resources/scripts/download/u-boot b/resources/scripts/download/u-boot
new file mode 100755
index 00000000..704d1c3a
--- /dev/null
+++ b/resources/scripts/download/u-boot
@@ -0,0 +1,123 @@
+#!/usr/bin/env bash
+
+#  helper script: download u-boot
+#
+#	Copyright (C) 2014, 2015, 2016, 2020, 2021 Leah Rowe <info@minifree.org>
+#	Copyright (C) 2021 Denis 'GNUtoo' Carikli  <GNUtoo@cyberdimension.org>
+#
+#	This program is free software: you can redistribute it and/or modify
+#	it under the terms of the GNU General Public License as published by
+#	the Free Software Foundation, either version 3 of the License, or
+#	(at your option) any later version.
+#
+#	This program is distributed in the hope that it will be useful,
+#	but WITHOUT ANY WARRANTY; without even the implied warranty of
+#	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#	GNU General Public License for more details.
+#
+#	You should have received a copy of the GNU General Public License
+#	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+[ "x${DEBUG+set}" = 'xset' ] && set -v
+set -u -e
+
+# set this when you want to modify each u-boot tree
+# for example, you want to test custom patches
+# NODELETE= ./download coreboot
+deleteblobs="true"
+[ "x${NODELETE+set}" = 'xset' ] && deleteblobs="false"
+
+# Error handling is extreme in this script.
+# This script handles the internet, and Git. Both are inherently unreliable.
+[[ -f build_error ]] && rm -f build_error
+
+downloadfor() {
+	uboot_revision="v2021.07"
+	uboot_dir="u-boot/u-boot"
+	if [ -d "${uboot_dir}" ]; then
+	    printf \
+		"REMARK: '%s' directory already exists. Skipping setup.\n" \
+		"${uboot_dir}"
+		return 0
+	fi
+
+	if [ ! -d "${uboot_dir}" ]; then
+		mkdir -p "${uboot_dir}"
+	fi
+
+	if [ ! -d "${uboot_dir}" ]; then
+	    printf \
+		"ERROR: '%s' directory not created. Check file system permissions\n" \
+		"${uboot_dir}"
+		return 1
+	fi
+
+	if [ ! -d "${uboot_dir}/.git" ] && [ -d "${uboot_dir}" ]; then
+		rm -Rf "${uboot_dir}"
+	fi
+
+	if [ ! -d "${uboot_dir}" ]; then
+		printf "Download u-boot from upstream:\n"
+		git clone https://source.denx.de/u-boot/u-boot \
+		    "${uboot_dir}" || \
+		    rm -Rf "${uboot_dir}"
+		if [ ! -d "${uboot_dir}" ]; then
+		    printf \
+			"ERROR: %s: Problem with git-clone. Network issue?\n" \
+			"download/u-boot"
+			return 1
+		fi
+	else
+		git -C "${uboot_dir}" pull || touch build_error
+		if [ -f build_error ]; then
+		    printf \
+			"ERROR: %s: Problem with git-pull. Network issue?\n" \
+			"download/u-boot"
+			return 1
+		fi
+	fi
+
+	git -C "${uboot_dir}" reset --hard ${uboot_revision} || \
+	    touch build_error
+	if [ -f build_error ]; then
+	    printf \
+		"ERROR: %s: Unable to reset to commit ID/tag '%s' for board '%s' on tree '%s'\n" \
+		"download/u-boot" "${uboot_revision}" "${1}" "${uboot_dir}"
+		return 1
+	fi
+}
+
+strip_comments()
+{
+	file="$1"
+	# Remove comments
+	sed 's/#.*//' "${file}" | \
+	    # Remove lines composed of whitespaces only
+	    sed '/^\W\+$/d' | \
+		# Remove empty lines
+		sed '/^$/d'
+}
+
+printf "Downloading u-boot and (if exist in build system) applying patches\n"
+downloadfor
+
+rm -f "build_error"
+printf "\n\n"
+
+if [ "${deleteblobs}" = "true" ]; then
+	bloblist="resources/u-boot/default/blobs.list"
+
+	for blob_path in $(strip_comments "${bloblist}"); do
+		if echo "${blob_path}" | grep '/$' 2>&1 >/dev/null ; then
+			printf "Deleting blob directory: '%s/%s'\n" \
+			       "${uboot_dir}" "${blob_path}"
+			rm -rf "${uboot_dir}/${blob_path}"
+		else
+			printf "Deleting blob file: '%s/%s'\n" \
+			       "${uboot_dir}" "${blob_path}"
+			rm -f "${uboot_dir}/${blob_path}"
+		fi
+	done
+fi
+exit 0