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

1 files changed, 61 insertions, 0 deletions

diff --git a/main/syslinux/syslinux.post-upgrade b/main/syslinux/syslinux.post-upgrade
new file mode 100644
index 0000000000..90388668de
--- /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
+