From: Michal Sojka <sojkam1@fel.cvut.cz>
Date: Wed, 4 May 2016 13:16:07 +0000 (+0200)
Subject: Add support for chainloading another bootloader
X-Git-Tag: 20170423~10
X-Git-Url: https://rtime.felk.cvut.cz/gitweb/novaboot.git/commitdiff_plain/987ae7bae392f561c6d02ba7b3b1a5d9f7bd445f?ds=sidebyside

Add support for chainloading another bootloader
---

diff --git a/README.pod b/README.pod
index 6e63d5b..21edb52 100644
--- a/README.pod
+++ b/README.pod
@@ -718,6 +718,16 @@ file mentioned there is copied to the same place as in case of C<load>
 configuration. Such a file can be used by the target for other
 purposed than booting, e.g. at OS runtime or for firmware update.
 
+=item C<chld>
+
+Chainload another bootloader. Instead of loading multiboot modules
+identified with C<load> keyword, run another bootloader. This is
+currently supported only by pulsar and can be used to load e.g. Grub
+as in the example below:
+
+ chld boot/grub/i386-pc/core.0
+
+
 =item C<run>
 
 Lines starting with C<run> keyword contain shell commands that are run
diff --git a/novaboot b/novaboot
index 27bc666..656ea84 100755
--- a/novaboot
+++ b/novaboot
@@ -301,7 +301,7 @@ my @scripts;
 my $file;
 my $EOF;
 my $last_fn = '';
-my ($modules, $variables, $generated, $copy, $continuation) = ([], {}, [], []);
+my ($modules, $variables, $generated, $copy, $chainload, $continuation) = ([], {}, [], []);
 my $skip_reading = defined($on_opt) || defined($off_opt);
 while (!$skip_reading && ($_ = <>)) {
     if ($ARGV ne $last_fn) { # New script
@@ -313,6 +313,7 @@ while (!$skip_reading && ($_ = <>)) {
 			 'variables' => $variables = {},
 			 'generated' => $generated = [],
 			 'copy' => $copy = [],
+			 'chainload' => $chainload = [],
 	};
 
     }
@@ -368,6 +369,10 @@ while (!$skip_reading && ($_ = <>)) {
 	push @$copy, process_load_copy($_);
 	next;
     }
+    if (s/^chld *//) {		# Chainload line
+	push @$chainload, process_load_copy($_);
+	next;
+    }
     if (/^run (.*)/) {		# run line
 	push @$generated, {command => $1};
 	next;
@@ -535,26 +540,30 @@ sub generate_grub2_config($$$$;$$)
     return $filename;
 }
 
-sub generate_pulsar_config($$)
+sub generate_pulsar_config($$$)
 {
-    my ($filename, $modules_ref) = @_;
+    my ($filename, $modules_ref, $chainload_ref) = @_;
     open(my $fg, '>', $filename) or die "$filename: $!";
     print $fg "root $pulsar_root\n" if defined $pulsar_root;
-    my $first = 1;
-    my ($kbin, $kcmd);
-    foreach (@$modules_ref) {
-	if ($first) {
-	    $first = 0;
-	    ($kbin, $kcmd) = split(' ', $_, 2);
-	    $kcmd = '' if !defined $kcmd;
-	} else {
-	    my @args = split;
-	    s|\brom://|$rom_prefix|g;
-	    print $fg "load $_\n";
+    if (scalar(@$chainload_ref) > 0) {
+	print $fg "chld $$chainload_ref[0]\n";
+    } else {
+	my $first = 1;
+	my ($kbin, $kcmd);
+	foreach (@$modules_ref) {
+	    if ($first) {
+		$first = 0;
+		($kbin, $kcmd) = split(' ', $_, 2);
+		$kcmd = '' if !defined $kcmd;
+	    } else {
+		my @args = split;
+		s|\brom://|$rom_prefix|g;
+		print $fg "load $_\n";
+	    }
 	}
+	# Put kernel as last - this is needed for booting Linux and has no influence on non-Linux OSes
+	print $fg "exec $kbin $kcmd\n";
     }
-    # Put kernel as last - this is needed for booting Linux and has no influence on non-Linux OSes
-    print $fg "exec $kbin $kcmd\n";
     close($fg);
     print("novaboot: Created $builddir/$filename\n");
     return $filename;
@@ -869,13 +878,14 @@ foreach my $script (@scripts) {
     my @bootloader_configs;
     push @bootloader_configs, generate_grub_config($grub_config, $config_name, $prefix, $modules, $grub_preamble) if (defined $grub_config);
     push @bootloader_configs, generate_grub2_config($grub2_config, $config_name, $prefix, $modules, $grub_preamble, $grub2_prolog) if (defined $grub2_config);
-    push @bootloader_configs, generate_pulsar_config('config-'.($pulsar||'novaboot'), $modules) if (defined $pulsar);
+    push @bootloader_configs, generate_pulsar_config('config-'.($pulsar||'novaboot'), $modules, $chainload) if (defined $pulsar);
 
 ### Run scons or make
     {
 	my @all;
 	push @all, @$modules;
 	push @all, @$copy;
+	push @all, @$chainload;
 	my @files = map({ ($file) = m/([^ ]*)/; $file; } @all);
 
 	# Filter-out generated files
@@ -1946,6 +1956,16 @@ file mentioned there is copied to the same place as in case of C<load>
 configuration. Such a file can be used by the target for other
 purposed than booting, e.g. at OS runtime or for firmware update.
 
+=item C<chld>
+
+Chainload another bootloader. Instead of loading multiboot modules
+identified with C<load> keyword, run another bootloader. This is
+currently supported only by pulsar and can be used to load e.g. Grub
+as in the example below:
+
+ chld boot/grub/i386-pc/core.0
+
+
 =item C<run>
 
 Lines starting with C<run> keyword contain shell commands that are run
diff --git a/tests/novaboot.wv b/tests/novaboot.wv
index da97b45..362afaa 100755
--- a/tests/novaboot.wv
+++ b/tests/novaboot.wv
@@ -19,6 +19,13 @@ create_dummy
 WVPASS ./script --gen-only --pulsar --pulsar-root=ASDF
 WVPASS grep "root ASDF" config-novaboot
 
+WVSTART Pulsar supports chld
+create_script <<EOF
+chld grub
+EOF
+WVPASS ./script --gen-only --pulsar
+WVPASS grep "chld grub" config-novaboot
+
 WVSTART Configuration files
 create_dummy
 echo '1;' > .novaboot