main/syslinux: misc update-extlinux fixes

- rename /etc/extlinux-conf to /etc/update-extlinux.conf

- Do not exit with fail if update-extlinux.conf is missing
- Always warn if root= is not defined in update-extlinux.conf
- Try harder to detect the root device by parsing /proc/mounts
- Exit with error if we cannot detect the Root device
- Rename fancy_menu to vesa_menu
- Unifiy the code generating vesa/standard menus
- Keep a backup of old extlinux.conf
- add "overwrite" config option so it is possible to skip overwriting
  the extlinux.conf.

- Added a post-upgrade that imports current extlinux.conf to
  update-extlinux.conf

4 files changed, 159 insertions, 46 deletions

diff --git a/main/syslinux/APKBUILD b/main/syslinux/APKBUILD
index 5a962cfddd6..6687475c53a 100644
--- a/main/syslinux/APKBUILD
+++ b/main/syslinux/APKBUILD
@@ -1,16 +1,17 @@
 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
 pkgname=syslinux
 pkgver=4.04
-pkgrel=4
-pkgdesc="a boot loader for the Linux operating system which operates off an MS-DOS/Windows FAT filesystem."
+pkgrel=5
+pkgdesc="Boot loader for the Linux operating system"
 url="http://syslinux.org"
 arch="x86 x86_64"
 license="GPL"
 makedepends="nasm perl"
 depends="mtools blkid"
-triggers=""
+triggers="syslinux.trigger=/boot"
+install="syslinux.post-upgrade"
 source="http://www.kernel.org/pub/linux/utils/boot/syslinux/${pkgver%%.*}.xx/$pkgname-$pkgver.tar.bz2
-	extlinux.conf
+	update-extlinux.conf
 	update-extlinux
 	"
 subpackages="$pkgname-doc"
@@ -30,11 +31,11 @@ package() {
 	cd "$_builddir"
 	make INSTALLROOT="$pkgdir" MANDIR=/usr/share/man local-install
 
-	mkdir -p "$pkgdir"/etc
-	cp "$srcdir"/extlinux.conf "$pkgdir"/etc/
+	mkdir -p "$pkgdir"/etc/update-extlinux.d
+	cp "$srcdir"/update-extlinux.conf "$pkgdir"/etc/
 	cp "$srcdir"/update-extlinux "$pkgdir"/sbin/
 }
 
 md5sums="a3936208767eb7ced65320abe2e33a10  syslinux-4.04.tar.bz2
-37f8ae1cbb41b68241d6027abd828318  extlinux.conf
-0d769b8a7c01137535bbd26f130a0658  update-extlinux"
+14443fe391bd315a54478851abdc32cb  update-extlinux.conf
+7164c110dae13a8d06d175943e48b841  update-extlinux"
diff --git a/main/syslinux/syslinux.post-upgrade b/main/syslinux/syslinux.post-upgrade
new file mode 100644
index 00000000000..90388668de9
--- /dev/null
+++ b/main/syslinux/syslinux.post-upgrade
@@ -0,0 +1,61 @@
+#!/bin/sh
+
+# find given append opt
+get_append_opt() {
+	awk -v search="$1" '
+		$1 == "append" || $1 == "APPEND" {
+		        split($0, a);
+		        for (i in a) {
+		                if (index(a[i], search) == 1) {
+	        	                print a[i];
+				}	
+			}
+		}' /boot/extlinux.conf | sort | uniq
+}
+
+# print default kernel options
+get_default_opts() {
+	awk '
+		$1 == "append" || $1 == "APPEND" {
+			opts="";
+			space="";
+		        split($0, a);
+		        for (i in a) {
+		                if (i != 1 \
+				    && (index(a[i], "root=") != 1) \
+				    && (index(a[i], "initrd=") != 1) \
+				    && (index(a[i], "modules=") != 1)) {
+	        	                opts = opts space a[i];
+					space = " ";
+				}
+			}
+			print opts;
+		}
+		' /boot/extlinux.conf | sort | uniq
+}
+
+if ! [ -f /boot/extlinux.conf ]; then
+	exit 0
+fi
+
+# check if we already have a generated extlinux.conf
+if grep -q '^# Generated by update-extlinux' /boot/extlinux.conf; then
+	exit 0
+fi
+
+# try fish out the kernel opts from extlinuix.conf's append line
+root=$(get_append_opt 'root=' | head -n 1)
+modules=$(get_append_opt 'modules=' | head -n 1)
+opts=$(get_default_opts | head -n 1)
+
+# populate update-extlinux.conf with the info we know
+if [ -n "$root" ]; then
+	sed -i -e "/^root=/s|.*|$root|g" /etc/update-extlinux.conf
+fi
+if [ -n "$modules" ]; then
+	sed -i -e "/^modules=/s|.*|$modules|g" /etc/update-extlinux.conf
+fi
+if [ -n "$opts" ]; then
+	sed -i -e "/^default_kernel_opts=/s|.*|default_kernel_opts=\"$opts\"|g" /etc/update-extlinux.conf
+fi
+
diff --git a/main/syslinux/update-extlinux b/main/syslinux/update-extlinux
index 25585334be8..a2488cc8df5 100755
--- a/main/syslinux/update-extlinux
+++ b/main/syslinux/update-extlinux
@@ -4,8 +4,13 @@ default=0
 timeout=5
 verbose=0
 
+conf=/boot/extlinux.conf
+myconf=/etc/update-extlinux.conf
+
 # read in extlinux settings
-source /etc/extlinux.conf
+if [ -f "$myconf" ]; then
+	. $myconf
+fi
 
 everbose() {
 	if [ "$verbose" = "0" ]; then
@@ -15,14 +20,44 @@ everbose() {
 	echo $*
 }
 
+ewarn() {
+	echo "WARNING:" $@ >&2
+}
+
+eerror() {
+	echo "ERROR:" $@ >&2
+	return 1
+}
+
 everbose "Updating extlinux configuration."
 
 if [ "x$root" = "x" ]; then
-	everbose "WARNING: Root device not specified, determining automatically."
-	everbose -n "Root device is: "
-	export `blkid -o export /dev/root`
-	root=UUID=$UUID
-	everbose $root
+	ewarn "Root device is not specified in $myconf."
+	blkid_export=$(blkid -o export /dev/root)
+	if [ -n "$blkid_export" ]; then
+		export $blkid_export
+	fi
+	if [ -z "$UUID" ]; then
+		# try parse /proc/mount for mounted /
+		dev=$(awk '$2 == "/" {dev=$1} END {print dev}' /proc/mounts)
+		if [ -n "$dev" ]; then
+			blkid_export=$(blkid -o export $dev)
+			if [ -n "$blkid_export" ]; then
+				export "$blkid_export"
+			fi
+		fi
+	fi
+	if [ -z "$UUID" ]; then
+		if [ -z "$dev" ]; then
+			eerror "Failed to detect root device"
+			exit 1
+		else
+			root=$dev
+		fi
+	else
+		root=UUID=$UUID
+	fi
+	everbose "Root device is: $root"
 fi
 
 everbose "Installing mboot.c32 to /boot."
@@ -32,29 +67,26 @@ everbose "Installing menu.c32 to /boot."
 cp /usr/share/syslinux/menu.c32 /boot
 
 rtimeout=$((${timeout}\*10))
+syslinux_menu=menu.c32
+menu_hidden=
+
 # vesa menu has been requested?
-if [ "$fancy_menu" = "1" ]; then
-	everbose "Installing vesamenu.c32 to /boot."
-	cp /usr/share/syslinux/vesamenu.c32 /boot
-
-	echo "DEFAULT vesamenu.c32" > /boot/extlinux.conf.new
-	echo "PROMPT 0" >> /boot/extlinux.conf.new
-	echo "MENU TITLE Alpine/$(uname -s) Boot Menu" >> /boot/extlinux.conf.new
-	if [ "$hidden" = "1" ]; then
-		echo "MENU HIDDEN" >> /boot/extlinux.conf.new
-	fi
-	echo "MENU AUTOBOOT Alpine will be booted automatically in # seconds." >> /boot/extlinux.conf.new
-	echo "TIMEOUT $rtimeout" >> /boot/extlinux.conf.new
-else
-	echo "DEFAULT menu.c32" > /boot/extlinux.conf.new
-	echo "PROMPT 0" >> /boot/extlinux.conf.new
-	echo "MENU TITLE Alpine/$(uname -s) Boot Menu" >> /boot/extlinux.conf.new
-	if [ "$hidden" = "1" ]; then
-		echo "MENU HIDDEN" >> /boot/extlinux.conf.new
-	fi
-	echo "MENU AUTOBOOT Alpine will be booted automatically in # seconds." >> /boot/extlinux.conf.new
-	echo "TIMEOUT $rtimeout" >> /boot/extlinux.conf.new
+if [ "$vesa_menu" = "1" ]; then
+	syslinux_menu=vesamenu.c32
+fi
+
+everbose "Installing $syslinux_menu to /boot."
+cp /usr/share/syslinux/vesamenu.c32 /boot
+
+echo "# Generated by update-extlinux" > $conf.new
+echo "DEFAULT $syslinux_menu" >> $conf.new
+echo "PROMPT 0" >> $conf.new
+echo "MENU TITLE Alpine/$(uname -s) Boot Menu" >> $conf.new
+if [ "$hidden" = "1" ]; then
+	echo "MENU HIDDEN" >> $conf.new
 fi
+echo "MENU AUTOBOOT Alpine will be booted automatically in # seconds." >> $conf.new
+echo "TIMEOUT $rtimeout" >> $conf.new
 
 lst=0
 for kernel in $(find /boot -name vmlinuz-* -type f); do
@@ -66,24 +98,38 @@ for kernel in $(find /boot -name vmlinuz-* -type f); do
 		initramfs="initrd=initramfs-$tag"
 	fi
 
-	echo "LABEL $lst" >> /boot/extlinux.conf.new
+	echo "LABEL $lst" >> $conf.new
 	if [ "$lst" = "$default" ]; then
-		echo "  MENU DEFAULT" >> /boot/extlinux.conf.new
+		echo "  MENU DEFAULT" >> $conf.new
 	fi
-	echo "  MENU LABEL Linux $tag" >> /boot/extlinux.conf.new
-	echo "  KERNEL $(basename $kernel)" >> /boot/extlinux.conf.new
-	echo "  APPEND $initramfs root=$root modules=$modules,$TYPE $default_kernel_opts" >> /boot/extlinux.conf.new
+	echo "  MENU LABEL Linux $tag" >> $conf.new
+	echo "  KERNEL $(basename $kernel)" >> $conf.new
+	echo "  APPEND $initramfs root=$root modules=${modules}${TYPE:+,$TYPE} $default_kernel_opts" >> $conf.new
+	echo "" >> $conf.new
 	lst=$(($lst + 1))
 done
 
 if [ -f "/boot/memtest" ]; then
 	everbose "Found memtest86+: /boot/memtest"
-	echo "LABEL $lst" >> /boot/extlinux.conf.new
-	echo "  MENU LABEL Memtest86+" >> /boot/extlinux.conf.new
-        echo "  KERNEL memtest" >> /boot/extlinux.conf.new
+	echo "LABEL $lst" >> $conf.new
+	echo "  MENU LABEL Memtest86+" >> $conf.new
+        echo "  KERNEL memtest" >> $conf.new
+	echo "" >> $conf.new
         lst=$(($lst + 1))
 fi
 
 everbose "$lst entries found."
 
-mv /boot/extlinux.conf.new /boot/extlinux.conf
+for entry in /etc/update-extlinux.d/*; do
+	[ -f "$entry" ] && cat $entry >> $conf.new
+done	
+
+if [ "$overwrite" = "1" ]; then
+	# keep a backup just in case
+	if [ -f "$conf" ]; then
+		mv $conf $conf.old
+	fi
+
+	mv $conf.new $conf
+fi
+
diff --git a/main/syslinux/extlinux.conf b/main/syslinux/update-extlinux.conf
index 05bdcc935be..17a47f22ca9 100644
--- a/main/syslinux/extlinux.conf
+++ b/main/syslinux/update-extlinux.conf
@@ -1,8 +1,13 @@
 # configuration for extlinux config builder
 
-# fancy_menu
+# overwrite
+# Overwrite current /boot/extlinux.conf. If this is not '1' we will only
+# write to /boot/extlinux.conf.new
+overwrite=1
+
+# vesa_menu
 # use fancy vesa menu (vesamenu.c32) menus, won't work with serial
-fancy_menu=0
+vesa_menu=0
 
 # default_kernel_opts
 # default kernel options