diff --git a/tools/fwpatcher/mksums.pl b/tools/fwpatcher/mksums.pl
new file mode 100755
index 0000000000..99786fe161
--- /dev/null
+++ b/tools/fwpatcher/mksums.pl
@@ -0,0 +1,69 @@
+#!/usr/bin/perl
+
+# This script creates the h100sums.h and h300sums.h files for fwpatcher.
+#
+# It expects a file tree with scrambled and descrambled
+# firmwares like this:
+# orig-firmware/
+#               h1xx/
+#                    1.66jp/
+#                           ihp_100.bin
+#                           ihp_100.hex
+#                           ihp_120.bin
+#                           ihp_120.hex
+#               h3xx/
+#                    1.29jp/
+#                           H300.bin
+#                           H300.hex
+# etc.
+#
+# It also expects the bootloader binaries in the current directory:
+# bootloader-h100.bin
+# bootloader-h120.bin
+# bootloader-h300.bin
+
+$orig_path = "~/orig-firmware";
+
+mksumfile("100");
+mksumfile("120");
+mksumfile("300");
+
+sub mksumfile {
+    ($model) = @_;
+
+    open FILE, ">h${model}sums.h" or die "Can't open h${model}sums.h";
+
+    print FILE "/* Checksums of firmwares for ihp_$model */\n";
+    print FILE "/* order: unpatched, patched */\n\n";
+
+    if($model < 300) {
+        foreach("1.63eu","1.63k", "1.63us", "1.65eu","1.65k", "1.65us",
+		"1.66eu", "1.66k", "1.66us", "1.66jp") {
+            `../mkboot $orig_path/h1xx/$_/ihp_$model.bin bootloader-h$model.bin ihp_$model.bin`;
+            `../scramble -iriver ihp_$model.bin ihp_$model.hex`;
+            $origsum = `md5sum $orig_path/h1xx/$_/ihp_$model.hex`;
+            chomp $origsum;
+            ($os, $or) = split / /, $origsum;
+            $sum = `md5sum ihp_$model.hex`;
+            chomp $sum;
+            ($s, $r) = split / /, $sum;
+            print FILE "/* $_ */\n";
+            print FILE "{\"$os\", \"$s\"},\n";
+        }
+    } else {
+        foreach("1.28eu", "1.28k", "1.28jp", "1.29eu", "1.29k", "1.29jp",
+		"1.30eu") {
+            `../mkboot -h300 $orig_path/h3xx/$_/H$model.bin bootloader-h$model.bin H$model.bin`;
+            `../scramble -iriver H$model.bin H$model.hex`;
+            $origsum = `md5sum $orig_path/h3xx/$_/H$model.hex`;
+            chomp $origsum;
+            ($os, $or) = split / /, $origsum;
+            $sum = `md5sum H$model.hex`;
+            chomp $sum;
+            ($s, $r) = split / /, $sum;
+            print FILE "/* $_ */\n";
+            print FILE "{\"$os\", \"$s\"},\n";
+        }
+    }
+    close FILE;
+}