From b7938695a1eff6c9245a2c8ac370c9cc8e60548b Mon Sep 17 00:00:00 2001
From: Steve McIntyre <steve@einval.com>
Date: Thu, 26 Nov 2015 00:02:55 +0000
Subject: [PATCH] Cope with changes in the isolinux menus added for auto CPU
 detection

Previously, this code was being confused by the re-use/overloading of
existing keywords in the ifcpu64.c module and not producing any menu
entries. Now, explicitly parse the new options and pick out just the
64-bit menus as they're a strict superset of the menus in isolinux.

This may enable some more issues, e.g. people trying to load a 64-bit
kernel on a 32-bit system, but until we get some auto-detection of CPU
in grub there's not much we can do about that. Let's get *something*
working at least.
---
 tools/boot/stretch/parse_isolinux | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/tools/boot/stretch/parse_isolinux b/tools/boot/stretch/parse_isolinux
index 161ff09e..8c97804e 100755
--- a/tools/boot/stretch/parse_isolinux
+++ b/tools/boot/stretch/parse_isolinux
@@ -33,6 +33,8 @@ my @menu_number = (1,0,0,0,0);
 my @menu_title = ('', '', '', '', '');
 my $menudepth = 0;
 my $pre = "";
+my $in_ifcpu = 0;
+my $amd64_label = "";
 my %menu;
 
 sub parse_file {
@@ -48,6 +50,31 @@ sub parse_file {
 	chomp $line;
 	if ($line =~ /^\s*include\ (.*\.cfg)/) {
 	    parse_file($1);
+	} elsif ($line =~ /label archdetect/) {
+	    # We don't have support for arch detection in Grub, so only
+	    # show the amd64 options
+	    $in_ifcpu = 1;
+	} elsif ($line =~ /kernel (.*c32)/) {
+	    # This tells us that the matching "append" data will have
+	    # the label we need to look for. Ugh!
+	    if ($1 =~ /ifcpu64/) {
+		$in_ifcpu = 2;
+	    }
+	} elsif ($line =~ /^\s*label (.*)/ && $1 =~ /$amd64_label/) {
+	    $in_ifcpu = 3;
+	} elsif ($line =~ /^\s*append\ (.*\.cfg)/) {
+	    if ($in_ifcpu == 3) {
+		parse_file($1);
+		$in_ifcpu = 1;
+	    }
+	} elsif ($line =~ /append (.*)$/ && $in_ifcpu == 2) {
+	    # Parse out the first entry - that's what we want to use
+	    # as a label elsewhere. Ugh!
+	    my @list = split(/ /, $1);
+	    $amd64_label = $list[0];
+	    $in_ifcpu = 1;
+	} elsif ($line =~ /default archdetect/) {
+	    $in_ifcpu = 0;
 	} else {
 	    push(@lines, $line);
 	}