From e13236c8a80f8caf80525cfab54020e71432e9b1 Mon Sep 17 00:00:00 2001
From: travankor <travankor@tuta.io>
Date: Sun, 29 Apr 2018 17:04:33 -0700
Subject: [PATCH] syslinux: Add /etc/kernel.d scripts.

---
 srcpkgs/syslinux/INSTALL.msg                  | 13 +++++
 .../files/kernel.d/syslinux.post-install      | 57 +++++++++++++++++++
 .../files/kernel.d/syslinux.post-remove       | 54 ++++++++++++++++++
 srcpkgs/syslinux/template                     |  7 ++-
 4 files changed, 130 insertions(+), 1 deletion(-)
 create mode 100755 srcpkgs/syslinux/files/kernel.d/syslinux.post-install
 create mode 100755 srcpkgs/syslinux/files/kernel.d/syslinux.post-remove

diff --git a/srcpkgs/syslinux/INSTALL.msg b/srcpkgs/syslinux/INSTALL.msg
index 8de3033d22c..eb2839ed0b3 100644
--- a/srcpkgs/syslinux/INSTALL.msg
+++ b/srcpkgs/syslinux/INSTALL.msg
@@ -4,3 +4,16 @@ Some optional packages must be installed for additional functionality:
  - gptfdisk: GPT support
  - efibootmgr: EFI support
  - dosfstools: EFI support
+
+Kernel.d scripts update the current and fallback kernel using these keywords:
+
+ - LABEL void
+ - LABEL voidfallback
+ - LINUX (or KERNEL)
+ - INITRD (or initrd)
+
+Avoid using these keywords for the MENU LABEL entry.
+
+For more information on how to setup syslinux.cfg, see:
+
+https://www.syslinux.org/wiki/?title=SYSLINUX#How_do_I_Configure_SYSLINUX.3F
diff --git a/srcpkgs/syslinux/files/kernel.d/syslinux.post-install b/srcpkgs/syslinux/files/kernel.d/syslinux.post-install
new file mode 100755
index 00000000000..79dcf15d903
--- /dev/null
+++ b/srcpkgs/syslinux/files/kernel.d/syslinux.post-install
@@ -0,0 +1,57 @@
+#!/bin/sh
+#
+# Kernel hook for SYSLINUX.
+#
+# Arguments passed to this script: $1 pkgname, $2 version.
+#
+PKGNAME="$1"
+VERSION="$2"
+CFGFILE="$ROOTDIR/boot/syslinux/syslinux.cfg"
+
+LABELVOID_LINENUMBER=$(
+  grep -nwm 1 'LABEL void' "$CFGFILE" |
+  awk '{print ($0+0)}')
+LABELVOIDFALLBACK_LINENUMBER=$(
+  grep -nwm 1 'LABEL voidfallback' "$CFGFILE" |
+  awk '{print ($0+0)}')
+
+VOID_KERNEL_LINENUMBER=$(
+  tail -n +"$LABELVOID_LINENUMBER" "$CFGFILE" |
+  grep -Enwm 1 'LINUX|KERNEL' |
+  awk '{print ($0+offset)}' offset="$((LABELVOID_LINENUMBER-1))")
+VOID_INITRD_LINENUMBER=$(
+  tail -n +"$LABELVOID_LINENUMBER" "$CFGFILE" |
+  grep -nwim 1 'INITRD' |
+  awk '{print ($0+offset)}' offset="$((LABELVOID_LINENUMBER-1))")
+VOIDFALLBACK_KERNEL_LINENUMBER=$(
+  tail -n +"$LABELVOIDFALLBACK_LINENUMBER" "$CFGFILE" |
+  grep -Enwm 1 'LINUX|KERNEL' |
+  awk '{print ($0+offset)}' offset="$((LABELVOIDFALLBACK_LINENUMBER-1))")
+VOIDFALLBACK_INITRD_LINENUMBER=$(
+  tail -n +"$LABELVOIDFALLBACK_LINENUMBER" "$CFGFILE" |
+  grep -nwim 1 'INITRD' |
+  awk '{print ($0+offset)}' offset="$((LABELVOIDFALLBACK_LINENUMBER-1))")
+
+#only use LINUX|KERNEL line to parse old kernel version
+OLD_VERSION=$(
+  sed -n "${VOID_KERNEL_LINENUMBER}p" "$CFGFILE" |
+  awk '{print $2}' |
+  awk 'BEGIN{FS="-"}{print $2}')
+OLD_FALLBACKVERSION=$(
+  sed -n "${VOIDFALLBACK_KERNEL_LINENUMBER}p" "$CFGFILE" |
+  awk '{print $2}' |
+  awk 'BEGIN{FS="-"}{print $2}')
+
+if [ -f "$CFGFILE" ]; then
+  sed -i "${VOID_KERNEL_LINENUMBER}s/$OLD_VERSION/$VERSION/" "$CFGFILE"
+  sed -i "${VOID_INITRD_LINENUMBER}s/$OLD_VERSION/$VERSION/" "$CFGFILE"
+  echo "Syslinux: Updated Kernel entry to $VERSION from $OLD_VERSION"
+  sed -i "${VOIDFALLBACK_KERNEL_LINENUMBER}s/$OLD_FALLBACKVERSION\
+/$OLD_VERSION/" "$CFGFILE"
+  sed -i "${VOIDFALLBACK_INITRD_LINENUMBER}s/$OLD_FALLBACKVERSION\
+/$OLD_VERSION/" "$CFGFILE"
+  echo "Syslinux: Updated Fallback Kernel entry to $OLD_VERSION from \
+$OLD_FALLBACKVERSION"
+fi
+
+exit 0
diff --git a/srcpkgs/syslinux/files/kernel.d/syslinux.post-remove b/srcpkgs/syslinux/files/kernel.d/syslinux.post-remove
new file mode 100755
index 00000000000..a945006951b
--- /dev/null
+++ b/srcpkgs/syslinux/files/kernel.d/syslinux.post-remove
@@ -0,0 +1,54 @@
+#!/bin/sh
+#
+# Kernel hook for SYSLINUX.
+#
+# Arguments passed to this script: $1 pkgname, $2 version.
+#
+PKGNAME="$1"
+VERSION="$2"
+CFGFILE="$ROOTDIR/boot/syslinux/syslinux.cfg"
+
+LABELVOID_LINENUMBER=$(
+  grep -nwm 1 'LABEL void' "$CFGFILE" |
+  awk '{print ($0+0)}')
+LABELVOIDFALLBACK_LINENUMBER=$(
+  grep -nwm 1 'LABEL voidfallback' "$CFGFILE" |
+  awk '{print ($0+0)}')
+
+VOID_KERNEL_LINENUMBER=$(
+  tail -n +"$LABELVOID_LINENUMBER" "$CFGFILE" |
+  grep -Enwm 1 'LINUX|KERNEL' |
+  awk '{print ($0+offset)}' offset="$((LABELVOID_LINENUMBER-1))")
+VOID_INITRD_LINENUMBER=$(
+  tail -n +"$LABELVOID_LINENUMBER" "$CFGFILE" |
+  grep -nwim 1 'INITRD' |
+  awk '{print ($0+offset)}' offset="$((LABELVOID_LINENUMBER-1))")
+VOIDFALLBACK_KERNEL_LINENUMBER=$(
+  tail -n +"$LABELVOIDFALLBACK_LINENUMBER" "$CFGFILE" |
+  grep -Enwm 1 'LINUX|KERNEL' |
+  awk '{print ($0+offset)}' offset="$((LABELVOIDFALLBACK_LINENUMBER-1))")
+
+#only use LINUX|KERNEL line to parse old kernel version
+OLD_VERSION=$(
+  sed -n "${VOID_KERNEL_LINENUMBER}p" "$CFGFILE" |
+  awk '{print $2}' |
+  awk 'BEGIN{FS="-"}{print $2}')
+OLD_FALLBACKVERSION=$(
+  sed -n "${VOIDFALLBACK_KERNEL_LINENUMBER}p" "$CFGFILE" |
+  awk '{print $2}' |
+  awk 'BEGIN{FS="-"}{print $2}')
+
+if [ -f "$CFGFILE" ]; then
+  if [ -f "$ROOTDIR/boot/vmlinuz-$OLD_VERSION" ]; then
+  #do nothing
+  exit 0
+  else
+    sed -i "${VOID_KERNEL_LINENUMBER}s/$OLD_VERSION/$OLD_FALLBACKVERSION/" \
+    "$CFGFILE"
+    sed -i "${VOID_INITRD_LINENUMBER}s/$OLD_VERSION/$OLD_FALLBACKVERSION/" \
+    "$CFGFILE"
+    echo "Syslinux: Revert Kernel entry $OLD_VERSION to $OLD_FALLBACKVERSION"
+  fi
+fi
+
+exit 0
diff --git a/srcpkgs/syslinux/template b/srcpkgs/syslinux/template
index 15cff728fdf..b7c150b2825 100644
--- a/srcpkgs/syslinux/template
+++ b/srcpkgs/syslinux/template
@@ -1,7 +1,7 @@
 # Template file for 'syslinux'
 pkgname=syslinux
 version=6.03
-revision=4
+revision=5
 hostmakedepends="perl python nasm"
 makedepends="gnu-efi-libs libuuid-devel"
 short_desc="A boot loader for the Linux operating system"
@@ -40,4 +40,9 @@ do_install() {
 	rm ${DESTDIR}/usr/share/syslinux/com32/*.a
 	# Remove keytab-lilo to prevent conflict with LILO
 	rm ${DESTDIR}/usr/bin/keytab-lilo
+	# Setup kernel hooks
+	vinstall ${FILESDIR}/kernel.d/syslinux.post-install 750 \
+		etc/kernel.d/post-install 50-syslinux
+	vinstall ${FILESDIR}/kernel.d/syslinux.post-remove 750 \
+		etc/kernel.d/post-remove 50-syslinux
 }