1 files changed, 58 insertions, 0 deletions
diff --git a/perl-install/resize_fat/io.pm b/perl-install/resize_fat/io.pm
new file mode 100644
index 000000000..68443ad2a
--- /dev/null
+++ b/perl-install/resize_fat/io.pm
@@ -0,0 +1,58 @@
+package resize_fat::io; # $Id: io.pm 208669 2004-08-12 04:20:25Z prigaux $
+
+use diagnostics;
+use strict;
+
+use resize_fat::fat;
+use c;
+
+1;
+
+
+sub read($$$) {
+    my ($fs, $pos, $size) = @_;
+    my $buf = "\0" x $size;
+    sysseek $fs->{fd}, $pos, 0 or die "seeking to byte #$pos failed on device $fs->{fs_name}";
+    sysread $fs->{fd}, $buf, $size or die "reading at byte #$pos failed on device $fs->{fs_name}";
+    $buf;
+}
+sub write($$$$) {
+    my ($fs, $pos, $_size, $buf) = @_;
+    sysseek $fs->{fd}, $pos, 0 or die "seeking to byte #$pos failed on device $fs->{fs_name}";
+    syswrite $fs->{fd}, $buf or die "writing at byte #$pos failed on device $fs->{fs_name}";
+}
+
+sub read_cluster($$) {
+    my ($fs, $cluster) = @_;
+    my $buf;
+    my $pos = $fs->{cluster_offset} / 512 + $cluster * ($fs->{cluster_size} / 512);
+
+    c::lseek_sector(fileno $fs->{fd}, $pos, 0) or die "seeking to sector #$pos failed on device $fs->{fs_name}";
+    sysread $fs->{fd}, $buf, $fs->{cluster_size} or die "reading at sector #$pos failed on device $fs->{fs_name}";
+    $buf;
+}
+sub write_cluster($$$) {
+    my ($fs, $cluster, $buf) = @_;
+    my $pos = $fs->{cluster_offset} / 512 + $cluster * ($fs->{cluster_size} / 512);
+
+    c::lseek_sector(fileno $fs->{fd}, $pos, 0) or die "seeking to sector #$pos failed on device $fs->{fs_name}";
+    syswrite $fs->{fd}, $buf or die "writing at sector #$pos failed on device $fs->{fs_name}";
+}
+
+sub read_file($$) {
+    my ($fs, $cluster) = @_;
+    my $buf = '';
+
+    for (; !resize_fat::fat::is_eof($cluster); $cluster = resize_fat::fat::next($fs, $cluster)) {
+	$cluster == 0 and die "Bad FAT: unterminated chain\n";
+	$buf .= read_cluster($fs, $cluster);
+    }
+    $buf;
+}
+
+sub open {
+    my ($fs) = @_;
+
+    sysopen $fs->{fd}, $fs->{fs_name}, 2 or
+      sysopen $fs->{fd}, $fs->{fs_name}, 0 or die "error opening device $fs->{fs_name} for writing\n";
+}