nixpkgs/nixos/modules/system/boot/loader/generations-dir/generations-dir-builder.sh

106 lines
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#! @bash@/bin/sh -e
shopt -s nullglob
export PATH=/empty
for i in @path@; do PATH=$PATH:$i/bin; done
default=$1
if test -z "$1"; then
echo "Syntax: generations-dir-builder.sh <DEFAULT-CONFIG>"
exit 1
fi
echo "updating the boot generations directory..."
mkdir -p /boot
rm -Rf /boot/system* || true
target=/boot/grub/menu.lst
tmp=$target.tmp
# 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 /boot/kernels.
declare -A filesCopied
copyToKernelsDir() {
local src="$1"
local dst="/boot/kernels/$(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 $src $dstTmp
mv $dstTmp $dst
fi
filesCopied[$dst]=1
result=$dst
}
# Copy its kernel and initrd to /boot/kernels.
addEntry() {
local path="$1"
local generation="$2"
local outdir=/boot/system-$generation
if ! test -e $path/kernel -a -e $path/initrd; then
return
fi
local kernel=$(readlink -f $path/kernel)
local initrd=$(readlink -f $path/initrd)
if test -n "@copyKernels@"; then
copyToKernelsDir $kernel; kernel=$result
copyToKernelsDir $initrd; initrd=$result
fi
mkdir -p $outdir
ln -sf $(readlink -f $path) $outdir/system
ln -sf $(readlink -f $path/init) $outdir/init
ln -sf $initrd $outdir/initrd
ln -sf $kernel $outdir/kernel
if test $(readlink -f "$path") = "$default"; then
cp "$kernel" /boot/nixos-kernel
cp "$initrd" /boot/nixos-initrd
cp "$(readlink -f "$path/init")" /boot/nixos-init
mkdir -p /boot/default
# ln -sfT: overrides target even if it exists.
ln -sfT $(readlink -f $path) /boot/default/system
ln -sfT $(readlink -f $path/init) /boot/default/init
ln -sfT $initrd /boot/default/initrd
ln -sfT $kernel /boot/default/kernel
fi
}
if test -n "@copyKernels@"; then
mkdir -p /boot/kernels
fi
# Add all 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); do
link=/nix/var/nix/profiles/system-$generation-link
addEntry $link $generation
done
# Remove obsolete files from /boot/kernels.
for fn in /boot/kernels/*; do
if ! test "${filesCopied[$fn]}" = 1; then
rm -vf -- "$fn"
fi
done