diff options
Diffstat (limited to 'nixpkgs/nixos/modules/system/boot/loader/generic-extlinux-compatible/extlinux-conf-builder.sh')
-rw-r--r-- | nixpkgs/nixos/modules/system/boot/loader/generic-extlinux-compatible/extlinux-conf-builder.sh | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/nixpkgs/nixos/modules/system/boot/loader/generic-extlinux-compatible/extlinux-conf-builder.sh b/nixpkgs/nixos/modules/system/boot/loader/generic-extlinux-compatible/extlinux-conf-builder.sh new file mode 100644 index 000000000000..c780a89b102c --- /dev/null +++ b/nixpkgs/nixos/modules/system/boot/loader/generic-extlinux-compatible/extlinux-conf-builder.sh @@ -0,0 +1,141 @@ +#! @bash@/bin/sh -e + +shopt -s nullglob + +export PATH=/empty +for i in @path@; do PATH=$PATH:$i/bin; done + +usage() { + echo "usage: $0 -t <timeout> -c <path-to-default-configuration> [-d <boot-dir>] [-g <num-generations>]" >&2 + exit 1 +} + +timeout= # Timeout in centiseconds +default= # Default configuration +target=/boot # Target directory +numGenerations=0 # Number of other generations to include in the menu + +while getopts "t:c:d:g:" opt; do + case "$opt" in + t) # U-Boot interprets '0' as infinite and negative as instant boot + if [ "$OPTARG" -lt 0 ]; then + timeout=0 + elif [ "$OPTARG" = 0 ]; then + timeout=-10 + else + timeout=$((OPTARG * 10)) + fi + ;; + c) default="$OPTARG" ;; + d) target="$OPTARG" ;; + g) numGenerations="$OPTARG" ;; + \?) usage ;; + esac +done + +[ "$timeout" = "" -o "$default" = "" ] && usage + +mkdir -p $target/nixos +mkdir -p $target/extlinux + +# Convert a path to a file in the Nix store such as +# /nix/store/<hash>-<name>/file to <hash>-<name>-<file>. +cleanName() { + local path="$1" + echo "$path" | sed 's|^/nix/store/||' | sed 's|/|-|g' +} + +# Copy a file from the Nix store to $target/nixos. +declare -A filesCopied + +copyToKernelsDir() { + local src=$(readlink -f "$1") + local dst="$target/nixos/$(cleanName $src)" + # Don't copy the file if $dst already exists. This means that we + # have to create $dst atomically to prevent partially copied + # kernels or initrd if this script is ever interrupted. + if ! test -e $dst; then + local dstTmp=$dst.tmp.$$ + cp -r $src $dstTmp + mv $dstTmp $dst + fi + filesCopied[$dst]=1 + result=$dst +} + +# Copy its kernel, initrd and dtbs to $target/nixos, and echo out an +# extlinux menu entry +addEntry() { + local path=$(readlink -f "$1") + local tag="$2" # Generation number or 'default' + + if ! test -e $path/kernel -a -e $path/initrd; then + return + fi + + copyToKernelsDir "$path/kernel"; kernel=$result + copyToKernelsDir "$path/initrd"; initrd=$result + # XXX UGLY: maybe the system config should have a top-level "dtbs" entry? + dtbDir=$(readlink -m "$path/kernel/../dtbs") + if [ -d "$dtbDir" ]; then + copyToKernelsDir "$dtbDir"; dtbs=$result + fi + + timestampEpoch=$(stat -L -c '%Z' $path) + + timestamp=$(date "+%Y-%m-%d %H:%M" -d @$timestampEpoch) + nixosLabel="$(cat $path/nixos-version)" + extraParams="$(cat $path/kernel-params)" + + echo + echo "LABEL nixos-$tag" + if [ "$tag" = "default" ]; then + echo " MENU LABEL NixOS - Default" + else + echo " MENU LABEL NixOS - Configuration $tag ($timestamp - $nixosLabel)" + fi + echo " LINUX ../nixos/$(basename $kernel)" + echo " INITRD ../nixos/$(basename $initrd)" + if [ -d "$dtbDir" ]; then + echo " FDTDIR ../nixos/$(basename $dtbs)" + fi + echo " APPEND systemConfig=$path init=$path/init $extraParams" +} + +tmpFile="$target/extlinux/extlinux.conf.tmp.$$" + +cat > $tmpFile <<EOF +# Generated file, all changes will be lost on nixos-rebuild! + +# Change this to e.g. nixos-42 to temporarily boot to an older configuration. +DEFAULT nixos-default + +MENU TITLE ------------------------------------------------------------ +TIMEOUT $timeout +EOF + +addEntry $default default >> $tmpFile + +if [ "$numGenerations" -gt 0 ]; then + # Add up to $numGenerations generations of the system profile to the menu, + # in reverse (most recent to least recent) order. + for generation in $( + (cd /nix/var/nix/profiles && ls -d system-*-link) \ + | sed 's/system-\([0-9]\+\)-link/\1/' \ + | sort -n -r \ + | head -n $numGenerations); do + link=/nix/var/nix/profiles/system-$generation-link + addEntry $link $generation + done >> $tmpFile +fi + +mv -f $tmpFile $target/extlinux/extlinux.conf + +# Remove obsolete files from $target/nixos. +for fn in $target/nixos/*; do + if ! test "${filesCopied[$fn]}" = 1; then + echo "Removing no longer needed boot file: $fn" + chmod +w -- "$fn" + rm -rf -- "$fn" + fi +done |