no_comment

1 files changed, 72 insertions, 0 deletions

diff --git a/perl-install/resize_fat/dir_entry.pm b/perl-install/resize_fat/dir_entry.pm
new file mode 100644
index 000000000..cfee23dae
--- /dev/null
+++ b/perl-install/resize_fat/dir_entry.pm
@@ -0,0 +1,72 @@
+package resize_fat::dir_entry;
+
+use diagnostics;
+use strict;
+
+
+my $DELETED_FLAG      = 0xe5;
+my $VOLUME_LABEL_ATTR = 0x08;
+my $VFAT_ATTR         = 0x0f;
+my $DIRECTORY_ATTR    = 0x10;
+
+1;
+
+sub get_cluster($) {
+    my ($entry) = @_;
+    $entry->{first_cluster} + ($resize_fat::isFAT32 ? $entry->{first_cluster_high} * 65536 : 0);
+}
+sub set_cluster($$) {
+    my ($entry, $val) = @_;
+    $entry->{first_cluster} = $val & (1 << 16) - 1;
+    $entry->{first_cluster_high} = $val >> 16 if $resize_fat::isFAT32;
+}
+
+sub is_directory_raw($) {
+    my ($entry) = @_;
+    !is_special_entry($entry) && $entry->{attributes} & $DIRECTORY_ATTR;
+}
+
+sub is_directory($) {
+    my ($entry) = @_;
+    is_directory_raw($entry) && $entry->{name} !~ /^\.\.? /;
+}
+
+sub is_volume($) {
+    my ($entry) = @_;
+    !is_special_entry($entry) && $entry->{attributes} & $VOLUME_LABEL_ATTR;
+}
+
+sub is_file($) {
+    my ($entry) = @_;
+    !is_special_entry($entry) && !is_directory($entry) && !is_volume($entry) && $entry->{length};
+}
+
+
+sub is_special_entry($) {
+    my ($entry) = @_;
+    my ($c) = unpack "C", $entry->{name};
+
+    #- skip empty slots, deleted files, and 0xF6?? (taken from kernel)
+    $c == 0 || $c == $DELETED_FLAG || $c == 0xF6 and return 1;
+
+    $entry->{attributes} == $VFAT_ATTR and return 1;
+    0;
+}
+
+
+#- return true if entry has been modified
+sub remap {
+    my ($fat_remap, $entry) = @_;
+
+    is_special_entry($entry) and return;
+
+    my $cluster = get_cluster($entry);
+    my $new_cluster = $fat_remap->[$cluster];
+
+    #-print "remapping cluster ", get_first_cluster($fs, $entry), " to $new_cluster";
+
+    $new_cluster == $cluster and return; #- no need to modify
+
+    set_cluster($entry, $new_cluster);
+    1;
+}