From a9c15e5e653735f2f1bf85710cc6e30236cd2ee6 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <mageia@martin-whitaker.me.uk>
Date: Mon, 21 Dec 2020 14:17:11 +0000
Subject: Add option to configure rEFInd to not use EFI NVRAM (mga#27838)

The combination of this and installing in \EFI\BOOT provides a
workaround for machines where the NVRAM is broken or worn out.
---
 perl-install/bootloader.pm | 41 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

(limited to 'perl-install/bootloader.pm')

diff --git a/perl-install/bootloader.pm b/perl-install/bootloader.pm
index a9f3077a8..85278c547 100644
--- a/perl-install/bootloader.pm
+++ b/perl-install/bootloader.pm
@@ -705,9 +705,19 @@ sub read_refind() {
 	}
     }
     $bootloader{method} = 'refind';
+    #- Try both possible locations for the main config file. The default is to use NVRAM if the
+    #- config file isn't found.
+    $bootloader{use_nvram} = get_refind_use_nvram("$::prefix/boot/EFI/EFI/refind/refind.conf")
+                          && get_refind_use_nvram("$::prefix/boot/EFI/EFI/BOOT/refind.conf");
     \%bootloader;
 }
 
+sub get_refind_use_nvram {
+    my ($path) = @_;
+    #- The default is to use NVRAM, so test if it is explicitly disabled.
+    -r $path && (grep { /^\s*use_nvram\s+(false|off|0)/ } cat_utf8($path)) ? 0 : 1;
+}
+
 # FIXME: actually read back previous conf
 sub read_cromwell() {
     +{ method => 'cromwell' };
@@ -2426,7 +2436,12 @@ sub write_refind {
 
     my $default_kernel = readlink("$::prefix/boot/vmlinuz");
     if ($default_kernel) {
-	write_refind_previous_boot_var($default_kernel);
+	if ($bootloader->{use_nvram}) {
+	    write_refind_previous_boot_var($default_kernel);
+	} else {
+	    write_refind_previous_boot_file($default_kernel, "$::prefix/boot/EFI/EFI/refind");
+	    write_refind_previous_boot_file($default_kernel, "$::prefix/boot/EFI/EFI/BOOT");
+	}
     }
 }
 
@@ -2450,6 +2465,20 @@ sub write_refind_previous_boot_var {
     run_program::run('umount', $efivars) if !$already_mounted;
 }
 
+sub write_refind_previous_boot_file {
+    my ($kernel, $base_path) = @_;
+    return if ! -e "$base_path/refind.conf" || ! mkdir_p("$base_path/vars");
+    if (open(my $f, '>:raw', "$base_path/vars/PreviousBoot")) {
+	require Encode;
+	log::l("writing rEFInd $base_path/vars/PreviousBoot file");
+	print $f Encode::encode('UTF16-LE', "Boot boot\\$kernel");
+	print $f "\x00\x00";
+	close($f);
+    } else {
+	log::l("failed to write rEFInd $base_path/vars/PreviousBoot file");
+    }
+}
+
 sub install_refind {
     my ($bootloader, $all_hds) = @_;
 
@@ -2469,9 +2498,19 @@ sub install_refind {
 	run_program::rooted($::prefix, '/sbin/refind-install', '2>', \$error, @options)
 	  or die "refind-install failed: $error";
     }
+    #- Try both possible locations for the main config file.
+    set_refind_use_nvram($bootloader->{use_nvram}, "$::prefix/boot/EFI/EFI/refind/refind.conf");
+    set_refind_use_nvram($bootloader->{use_nvram}, "$::prefix/boot/EFI/EFI/BOOT/refind.conf");
     write_refind($bootloader, $all_hds);
 }
 
+sub set_refind_use_nvram {
+    my ($use_nvram, $path) = @_;
+    return if ! -w $path;
+    my $script = 's/^#?\s*use_nvram\s+.*/use_nvram ' . ($use_nvram ? 'true' : 'false') . '/';
+    run_program::run('sed', '-i', '-E', $script, $path) or die "failed to update $path";
+}
+
 sub when_config_changed_refind {
     my ($_bootloader) = @_;
     #- do not do anything
-- 
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