generate_firmware_patterns: rewrite to match caller's expectations

Initially it was interesting to pass “--package ALL” to create *.patterns
files for all packages found in the specified Components-* file(s), but
make_disc_trees.pl uses a call per package, so drop support for looping.

Remember whether modalias information was found for the requested package,
and only apply the firmware-sof-signed workaround when that's indeed the
requested package and when modalias information wasn't found (in case that
gets added to DEP-11 metadata at some point in the future). When using the
workaround, include a reminder in the logs.

tools/generate_firmware_patterns

@@ -21,10 +21,11 @@ use File::Slurp;
 use Getopt::Long;
 use YAML::XS;
 
+my $SOF = 'firmware-sof-signed';
 
 my $output_dir = '.';
 my $verbose;
-my $pkgname = "ALL";
+my $pkgname;
 
 GetOptions( "output-dir=s" => \$output_dir,
             "verbose"      => \$verbose,
@@ -37,7 +38,7 @@ sub format_alias {
 }
 
 
-sub process_components {
+sub generate_patterns_from_components {
     my $input = shift;
     my $content;
     print STDERR "processing $input\n"
@@ -53,7 +54,6 @@ sub process_components {
         die "only gz and xz suffixes are supported";
     }
 
-    my @packages;
     foreach my $array (Load $content) {
         next if not defined $array->{Provides};
         next if not defined $array->{Provides}->{modaliases};
@@ -61,9 +61,9 @@ sub process_components {
         print STDERR "found modaliases entries for firmware package ", $array->{Package}, "\n"
             if $verbose;
 
-        if ($pkgname eq "ALL" or $pkgname eq $array->{Package}) {
+        next if $pkgname ne $array->{Package};
 
-            my $patterns_file = $output_dir . "/" . $array->{Package} . ".patterns";
+        my $patterns_file = "$output_dir/$pkgname.patterns";
         printf STDERR "writing %d entries to %s\n",
             (scalar @{ $array->{Provides}->{modaliases} }),
             $patterns_file;
@@ -72,44 +72,19 @@ sub process_components {
         # the right ($), and replace each '*' with '.*':
         write_file($patterns_file,
                    format_alias( @{ $array->{Provides}->{modaliases} } ));
-            push @packages, $array->{Package};
+        return 1;
     }
-    }
+    return 0;
-    return @packages;
 }
 
 
-# Make sure the output directory exists:
-die "missing output directory $output_dir"
-    if ! -d $output_dir;
-
-write_file("$output_dir/README.txt",
-           "These files help Debian Installer detect helpful firmware packages (via hw-detect).\n");
-
-# Generate .patterns file to match firmware packages found in
-# Components-* files:
-my @all_packages;
-foreach my $component (@ARGV) {
-    die "missing metadata file $component"
-        if ! -f $component;
-    my @packages = process_components($component);
-    push @all_packages, @packages;
-}
-@all_packages = sort @all_packages;
-print STDERR "firmware packages found across all components: @all_packages\n"
-    if $verbose;
-
 # Workaround for firmware-sof-signed, which doesn't advertise firmware
 # files it might need through the MODULE_FIRMWARE() macro (meaning no
 # chance to generate DEP-11 info from there): alias info manually
 # extracted on 2023-01-18 (linux-image-6.1.0-1-amd64, 6.1.4-1).
 #
 # XXX: To be kept in sync! (#1029175)
-my $SOF = 'firmware-sof-signed';
+sub generate_patterns_for_firmware_sof_intel_workaround {
-if (! grep { $_ eq $SOF } @all_packages) {
-
-    if ($pkgname eq 'ALL' or $pkgname eq 'firmware-sof-signed') {
-
     # Extract on amd64, from the installed package, with the following
     # command. Note that descending under intel/ would lead to no
     # aliases, so stick to the top-level directory for sof:
@@ -174,12 +149,32 @@ if (! grep { $_ eq $SOF } @all_packages) {
         if $verbose;
 
     my $sof_file = $output_dir . "/" . $SOF . ".patterns";
-        printf STDERR "writing %d entries to %s\n",
+    printf STDERR "writing %d entries to %s (using the workaround)\n",
         (scalar @sof_aliases),
         $sof_file;
 
     write_file($sof_file,
                format_alias(@sof_aliases));
-        push @all_packages, $SOF;
-    }
 }
+
+
+# Make sure the output directory exists:
+die "missing output directory $output_dir"
+    if ! -d $output_dir;
+
+write_file("$output_dir/README.txt",
+           "These files help Debian Installer detect helpful firmware packages (via hw-detect).\n");
+
+# Search for the specified package in the Components-* files, and
+# generate patterns when it's found:
+my $done;
+foreach my $components (@ARGV) {
+    die "missing metadata file $components"
+        if ! -f $components;
+    $done = generate_patterns_from_components($components);
+    last if $done;
+}
+
+# Only apply the workaround when relevant:
+generate_patterns_for_firmware_sof_intel_workaround()
+    if ! $done and $pkgname eq $SOF;