Support reboot in non-chroot modes using grub and an init script

We use grub-2.06 as 2.12 has some packaging issues, and can't be
built in live-bootstrap for now.

steps/grub-2.06/import-gnulib.sh

@@ -0,0 +1,39 @@
+#!/bin/sh
+
+# SPDX-FileCopyrightText: 2021 Melg Eight <public.melg8@gmail.com>
+# SPDX-FileCopyrightText: 2023 fosslinux <fosslinux@aussies.space>
+# SPDX-FileCopyrightText: 2024 Gábor Stefanik <netrolller.3d@gmail.com>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# Regenerate unicode files
+pushd ../gnulib-d271f86/lib
+gcc -Iunictype -o gen-uni-tables gen-uni-tables.c
+mv ../../*.txt .
+./gen-uni-tables UnicodeData-9.0.0.txt PropList-9.0.0.txt DerivedCoreProperties-9.0.0.txt ArabicShaping-9.0.0.txt Scripts-9.0.0.txt Blocks-9.0.0.txt PropList-3.0.1.txt EastAsianWidth-9.0.0.txt LineBreak-9.0.0.txt WordBreakProperty-9.0.0.txt GraphemeBreakProperty-9.0.0.txt CompositionExclusions-9.0.0.txt SpecialCasing-9.0.0.txt CaseFolding-9.0.0.txt 9.0
+popd
+
+../gnulib-d271f86/gnulib-tool --import --local-dir=gl \
+  --lib=libgnu \
+  --source-base=grub-core/lib/gnulib \
+  --m4-base=m4 \
+  --doc-base=doc \
+  --tests-base=tests \
+  --aux-dir=build-aux \
+  --no-conditional-dependencies \
+  --no-libtool \
+  --macro-prefix=gl \
+  --no-vc-files \
+  argp \
+  base64 \
+  error \
+  fnmatch \
+  getdelim \
+  getline \
+  gettext-h \
+  gitlog-to-changelog \
+  mbswidth \
+  progname \
+  realloc-gnu \
+  regex \
+  save-cwd

steps/grub-2.06/pass1.sh

@@ -0,0 +1,35 @@
+# SPDX-FileCopyrightText: 2024 Gábor Stefanik <netrolller.3d@gmail.com>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+src_prepare() {
+    default
+
+    # Remove pregenerated gnulib files
+    pushd ../gnulib-d271f86
+    rm lib/unictype/ctype*.h
+    rm lib/unicase/tolower.h
+    popd
+
+    . ../../import-gnulib.sh
+
+    for patchname in fix-base64 fix-null-deref fix-null-state-deref fix-regcomp-uninit-token \
+        fix-regexec-null-deref fix-uninit-structure fix-unused-value fix-width no-abort; do
+        patch -d grub-core/lib/gnulib -p2 < "grub-core/lib/gnulib-patches/$patchname.patch"
+    done
+
+    ./autogen.sh
+
+    cp -a INSTALL INSTALL.grub
+    autoreconf-2.69 -vif
+    mv INSTALL.grub INSTALL
+}
+
+src_configure() {
+    CFLAGS="-Wno-error" ./configure --prefix="${PREFIX}" --sbindir="${PREFIX}/bin" --build=i686-pc-linux-musl
+}
+
+src_install() {
+    default
+    rm "${DESTDIR}${PREFIX}/share/info/dir"
+}

steps/grub-2.06/sources

@@ -0,0 +1,16 @@
+https://mirrors.kernel.org/gnu/grub/grub-2.06.tar.xz b79ea44af91b93d17cd3fe80bdae6ed43770678a9a5ae192ccea803ebb657ee1
+https://git.savannah.gnu.org/cgit/gnulib.git/snapshot/gnulib-d271f86.tar.gz 31d69d3d251e39135b5194ddc6f897910d344059f7494d96a739aecbf7ac2b66
+http://ftp.unicode.org/Public/9.0.0/ucd/UnicodeData.txt 68dfc414d28257b9b5d6ddbb8b466c768c00ebdf6cbf7784364a9b6cad55ee8f UnicodeData-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/PropList.txt f413ea8dbd3858de72f3148b47dd0586019761357d1481e3b65f3a025bc27f82 PropList-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/DerivedCoreProperties.txt 6662c7e30b572df5d948c092692f52bcc79ab36d49a063a73d6435042db6fb3b DerivedCoreProperties-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/ArabicShaping.txt 47cb62a53beea6d0263e2147331c7e751853c9327225d95bbe2d9e1dc3e1aa44 ArabicShaping-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/Scripts.txt fba415952f5654145acad220dc2b878f815c673474d2bb4928934e3ba6ccca1d Scripts-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/Blocks.txt 612127d4889032e55d82522e4a0c19793bda8aa8da14ecb3c696d17c83e6be13 Blocks-9.0.0.txt
+http://ftp.unicode.org/Public/3.0-Update1/PropList-3.0.1.txt 909eef4adbeddbdddcd9487c856fe8cdbb8912aa8eb315ed7885b6ef65f4dc4c
+http://ftp.unicode.org/Public/9.0.0/ucd/EastAsianWidth.txt 3382cb4980e0021e9d4312f2d099315cfab6100ce0ff63a22d6937bfa720bcb7 EastAsianWidth-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/LineBreak.txt e2698584982ccd96e0c688bbcd4d2c48a23805baa0a0084388ef2e50ebd30aad LineBreak-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/auxiliary/WordBreakProperty.txt cb2db065c77287e0f1d35b8c9b473d848b7566a1670439f67c357ca393084043 WordBreakProperty-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/auxiliary/GraphemeBreakProperty.txt 4bb8931857e0a698fd2ec4a51a84c6de33e48a50d8b4bf0b57d960c41d77a191 GraphemeBreakProperty-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/CompositionExclusions.txt 5623df16856ad4007c60bdfff6f054e087521becd24cb4006be69c3a1d851aee CompositionExclusions-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/SpecialCasing.txt dfc4f159c5c68328114ff17cd520451714a72ff48657287e5fe2f64344980695 SpecialCasing-9.0.0.txt
+http://ftp.unicode.org/Public/9.0.0/ucd/CaseFolding.txt 37d40cf8c2c35637f4a04e746814e1fc4eb764c272bed9238a87ee96a4866857 CaseFolding-9.0.0.txt