Improve pacman hook

The hook now reacts on updated files instead of updated packages, like
the `mkinitcpio` hook does.

This allows it to be triggered each time a kernel image is updated:
 - when a kernel package is updated (e.g. `linux`);
 - when a dependency is updated (e.g. `systemd`).

This also allows to only rebuild the kernel images that were actually
updated instead of always rebuilding all. The main script now accepts
kernel names as arguments for that.

Files have been renamed to be more consistent with the AUR package.

README.md

@@ -32,12 +32,12 @@ If your EFI partition is mounted as /boot and your kernels are installed there,
 sudo install.sh
 ```
 
-If not, please edit build_kernel.sh and install it manually. You can do it by running
+If not, please edit build_efi_kernel.sh and install it manually. You can do it by running
 
 ```
-cp build_kernel.sh to /opt
-mkdir -p /etc/pacman.d/hooks/
-cp kernel-update.hook /etc/pacman.d/hooks
+cp build_efi_kernel.sh to /opt
+mkdir -p /etc/pacman.d/hooks
+cp hook/* /etc/pacman.d/hooks/
 ```
 
 ## EFI boot entries

build_kernel.sh → build_efi_kernels.sh

@@ -1,34 +1,49 @@
-#!/bin/bash
+#!/bin/bash -e
 
 TARGET=/boot
 BOOTDIR=/boot
 UCODE=$BOOTDIR/intel-ucode.img
 EFISTUB=/usr/lib/systemd/boot/efi/linuxx64.efi.stub
 
-echo "Updating EFI kernels..."
+if [[ $# -gt 0 ]]; then
+	KERNEL_IMAGES=()
+	for KERNEL in "$@"; do
+		KERNEL_IMAGE="${BOOTDIR}/vmlinuz-${KERNEL}"
 
-for k in $BOOTDIR/vmlinuz*; do
+		if [ ! -f "${KERNEL_IMAGE}" ]; then
+			echo "Kernel \"${KERNEL}\" not available."
+
+			exit 1;
+		fi
+
+		KERNEL_IMAGES+=("${KERNEL_IMAGE}")
+	done
+else
+	KERNEL_IMAGES=($BOOTDIR/vmlinuz*)
+fi
+
+for k in "${KERNEL_IMAGES[@]}"; do
 	NAME=$(basename $k|sed 's/vmlinuz-//')
-	echo "  Building $NAME"
+	echo "Updating EFI kernel $NAME..."
 	INITRD="$BOOTDIR/initramfs-$NAME.img"
 
 	if [ -f "$UCODE" ]; then
 		cat "$UCODE" "$INITRD" > /tmp/initrd.bin
 		INITRDFILE=/tmp/initrd.bin
 	else
 		# Do not fail on AMD systems
-		echo "    Intel microcode not found. Skipping."
+		echo "  Intel microcode not found. Skipping."
 		INITRDFILE="$INITRD"
 	fi
 
 	# Check for custom command line for the kernel.
 	CMDLINE="$BOOTDIR/cmdline-$NAME.txt"
 	if [ -f "$CMDLINE" ]; then
-		echo "    Using custom command line $CMDLINE"
+		echo "  Using custom command line $CMDLINE"
 	else
 		CMDLINE="$BOOTDIR/cmdline.txt"
 		if [ ! -f "$CMDLINE" ]; then
-			echo "CMDLINE missing. Extracting from running kernel..."
+			echo "  CMDLINE missing. Extracting from running kernel..."
 			cat /proc/cmdline |sed 's/BOOT_IMAGE=[^ ]* \?//' > "$CMDLINE"
 		fi
 	fi

hook/efi-kernel-update.hook

@@ -0,0 +1,12 @@
+[Trigger]
+Type = Path
+Operation = Upgrade
+Operation = Install
+Target = usr/lib/modules/*/vmlinuz
+Target = usr/lib/initcpio/*
+
+[Action]
+Description = Updating EFI kernel images
+When = PostTransaction
+Exec = /etc/pacman.d/hooks/efi-kernel-update.sh
+NeedsTargets

hook/efi-kernel-update.sh

@@ -0,0 +1,17 @@
+#!/bin/bash -e
+
+while read -r updated_file; do
+	if [[ $updated_file == usr/lib/initcpio/* ]]; then
+		# all kernels images have been updated
+		build_efi_kernels
+
+		break
+	fi
+
+	pkgbase_file="${updated_file%/vmlinuz}/pkgbase"
+	if ! read -r kernel > /dev/null 2>&1 < "${pkgbase_file}"; then
+		continue
+	fi
+
+	build_efi_kernels "${kernel}"
+done

install.sh

@@ -10,9 +10,9 @@ if [ "$(id -u)" -ne 0 ]; then
 	exit 1
 fi
 
-cp build_kernel.sh /opt/
+cp build_efi_kernels.sh /opt/
 mkdir -p /etc/pacman.d/hooks
-cp kernel-update.hook /etc/pacman.d/hooks/
+cp hooks/* /etc/pacman.d/hooks/
 
 echo "Install completed. Building kernels..."