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/improve/finalize_fhs.sh

@@ -16,6 +16,11 @@ mount | grep '/sys' &> /dev/null || (mkdir -p /sys; mount -t sysfs sysfs /sys)
 mount | grep '/tmp' &> /dev/null || (mkdir -p /tmp; mount -t tmpfs tmpfs /tmp)
 mount | grep '/dev/shm' &> /dev/null || (mkdir -p /dev/shm; mount -t tmpfs tmpfs /dev/shm)
 
+if [ "${CHROOT}" = False ]; then
+    rm /etc/mtab
+    ln -s /proc/mounts /etc/mtab
+fi
+
 # Add /etc/resolv.conf
 if [ ! -e "/etc/resolv.conf" ]; then
     echo 'nameserver 1.1.1.1' > /etc/resolv.conf

steps/improve/make_bootable.sh

@@ -0,0 +1,68 @@
+#!/bin/sh
+
+# SPDX-FileCopyrightText: 2024 Gábor Stefanik <netrolller.3d@gmail.com>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# find the physical disk name
+PHYSICAL=${DISK}
+
+# take care of e.g. "sda1"
+if echo "${DISK}" | grep -Eq '^[a-z]{3}[0-9]+$'
+then
+    PHYSICAL=$(echo "${DISK}" | sed -E 's/^([a-z]{3})[0-9]+$/\1/')
+fi
+
+# take care of e.g. "mmcblk0p1"
+if echo "${DISK}" | grep -Eq '^[a-z0-9]{3,}p[0-9]+$'
+then
+    PHYSICAL=$(echo "${DISK}" | sed -E 's/^([a-z0-9]{3,})p[0-9]+$/\1/')
+fi
+
+grub-install "/dev/${PHYSICAL}"
+
+cat > /boot/grub/grub.cfg <<- EOF
+set timeout=5
+set default=0
+menuentry 'Linux live-bootstrap (4.9.10)' {
+    insmod part_msdos
+    set root='grub-probe -d /dev/${DISK} -t bios_hints | sed -e 's/ //g')'
+    linux /boot/linux-4.9.10 root=/dev/${DISK} rw $(cat /proc/cmdline)
+}
+EOF
+
+cat > /init <<- 'EOF'
+#!/usr/bin/bash
+cd /steps
+. ./bootstrap.cfg
+. ./env
+. ./helpers.sh
+trap 'env PATH=${PREFIX}/bin PS1="[TRAP] \w # " bash -i' ERR
+# /dev is automounted by the kernel at this point
+mount | grep '/proc' &> /dev/null || (mkdir -p /proc; mount -t proc proc /proc)
+mount | grep '/sys' &> /dev/null || (mkdir -p /sys; mount -t sysfs sysfs /sys)
+# Make /tmp a ramdisk (speeds up configure etc significantly)
+mount | grep '/tmp' &> /dev/null || (mkdir -p /tmp; mount -t tmpfs tmpfs /tmp)
+mount | grep '/dev/shm' &> /dev/null || (mkdir -p /dev/shm; mount -t tmpfs tmpfs /dev/shm)
+
+if test -f /swapfile; then
+    swapon /swapfile
+fi
+
+if [ "${CHROOT}" = False ]; then
+    dhcpcd --waitip=4
+fi
+
+env - PATH=${PREFIX}/bin PS1="\w # " setsid openvt -fec1 -- bash -i
+
+# ignore errors due to fstab or swapfile not existing
+swapoff -a &> /dev/null || true
+sync
+# sysrq to avoid device busy; then mount to wait for it to finish
+echo u > /proc/sysrq-trigger
+mount -o remount,ro /
+echo o > /proc/sysrq-trigger # power off
+while true; do sleep 1; done
+EOF
+
+chmod +x /init

steps/improve/swap.sh

@@ -1,4 +1,3 @@
-
 #!/bin/sh
 #
 # SPDX-FileCopyrightText: 2024 Gábor Stefanik <netrolller.3d@gmail.com>