diff --git a/Makefile b/Makefile
index 89a151c..8e938db 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 TARGET = umd_livepatch
-C_OBJS = io_funcs.o main.o
+C_OBJS = patch.o io_funcs.o main.o
 OBJS = $(C_OBJS) imports.o
 all: $(TARGET).prx
 INCDIR = $(ARKROOT)/common/include $(ARKROOT)/core/systemctrl/include $(LIBRSYNC)/src
diff --git a/rpatch.c b/patch.c
similarity index 91%
rename from rpatch.c
rename to patch.c
index 1191d4f..8c46abe 100644
--- a/rpatch.c
+++ b/patch.c
@@ -1,5 +1,5 @@
 #include "io_funcs.h"
-#include "rpatch.h"
+#include "patch.h"
 
 lp_UMDiffCommand cmd_buffer[1024];
 
diff --git a/rpatch.h b/patch.h
similarity index 53%
rename from rpatch.h
rename to patch.h
index 164c0b6..7cb3ea4 100644
--- a/rpatch.h
+++ b/patch.h
@@ -1,9 +1,9 @@
-#ifndef __RPATCH_H
-#define __RPATCH_H
+#ifndef __PATCH_H
+#define __PATCH_H
 
 #include "umdiff/umdiff.h"
 
 int
 lp_loadCmdsForIndex(long sector);
 
-#endif //__RPATCH_H
+#endif //__PATCH_H
diff --git a/umdiff/.ccls b/umdiff/.ccls
new file mode 100644
index 0000000..a4b5316
--- /dev/null
+++ b/umdiff/.ccls
@@ -0,0 +1,3 @@
+gcc
+-I./librsync/src
+-D__CCLS__
diff --git a/umdiff/.envrc b/umdiff/.envrc
new file mode 100644
index 0000000..e69de29
diff --git a/umdiff/.gitattributes b/umdiff/.gitattributes
new file mode 100644
index 0000000..03b6e71
--- /dev/null
+++ b/umdiff/.gitattributes
@@ -0,0 +1 @@
+*.rl.h   linguist-generated=true
diff --git a/umdiff/.gitignore b/umdiff/.gitignore
new file mode 100644
index 0000000..e3f5778
--- /dev/null
+++ b/umdiff/.gitignore
@@ -0,0 +1,2 @@
+umdiff
+*.rl
diff --git a/umdiff/Makefile b/umdiff/Makefile
index 39973c1..82103c6 100644
--- a/umdiff/Makefile
+++ b/umdiff/Makefile
@@ -3,6 +3,8 @@ C_OBJS = main.o rdiff.o
 OBJS   = $(C_OBJS)
 
 CMAKE := cmake
+RAGEL := ragel
+DOCOPT2RAGEL := docopt2ragel
 
 LIBRSYNC_SOURCE := librsync
 
@@ -13,8 +15,14 @@ else
 	LIBS += -lrsync
 endif
 
-$(TARGET): $(OBJS)
-	$(CC) -o $@ $^ $(CFLAGS) $(LIBS)
+$(TARGET): $(OBJS) usage.rl.h
+	$(CC) -o $@ $(OBJS) $(CFLAGS) $(LIBS)
+
+usage.rl: USAGE
+	$(DOCOPT2RAGEL) USAGE > $@
+
+%.rl.h: %.rl
+	$(RAGEL) $< -o $@
 
 librsync:
 	git clone https://github.com/librsync/librsync
@@ -25,3 +33,8 @@ librsync.a: $(LIBRSYNC_SOURCE)
 	mv librsync.build/librsync.a .
 	rm -rf librsync.build
 
+
+clean:
+	rm -rf librsync $(OBJS) *.rl $(TARGET)
+
+.PHONY: clean
diff --git a/umdiff/USAGE b/umdiff/USAGE
new file mode 100644
index 0000000..4dcd68e
--- /dev/null
+++ b/umdiff/USAGE
@@ -0,0 +1,10 @@
+umdiff - Generate patch files for use with umd-livepatch
+
+Usage:
+  umdiff delta <source_file> <target_file> <output_file>
+  umdiff patch <source_file> <umdiff_file> <output_file>
+  umdiff from-rdiff <rdiff_file> <output_file>
+  umdiff --help
+
+Options:
+  -h --help  Prints a short usage summary.
diff --git a/umdiff/main.c b/umdiff/main.c
index 8677c17..d5d2745 100644
--- a/umdiff/main.c
+++ b/umdiff/main.c
@@ -1,4 +1,18 @@
+#include "usage.rl.h"
+
 int main(int argc, char *argv[])
 {
+    int res;
+    options_t opts;
 
+    res = parse_options(argc, argv, &opts);
+    if (res == -1)
+        return -1;
+
+    if (opts.help) {
+        show_usage();
+        return 0;
+    }
+
+    return 1;
 }
diff --git a/umdiff/rdiff.c b/umdiff/rdiff.c
index e69de29..25d0167 100644
--- a/umdiff/rdiff.c
+++ b/umdiff/rdiff.c
@@ -0,0 +1 @@
+#include <librsync.h>
diff --git a/umdiff/usage.rl.h b/umdiff/usage.rl.h
new file mode 100644
index 0000000..e8399b3
--- /dev/null
+++ b/umdiff/usage.rl.h
@@ -0,0 +1,337 @@
+
+#line 1 "usage.rl"
+#include <stdio.h>
+#include <string.h>
+
+#define BUFLEN 1024
+#define BUFSIZE 2048
+
+typedef struct
+{
+    /* commands */
+    int delta;
+    int fromrdiff;
+    int patch;
+
+    /* flags */
+    int help;
+
+    /* options */
+    
+
+    /* arguments */
+    char* output_file;
+    char* rdiff_file;
+    char* source_file;
+    char* target_file;
+    char* umdiff_file;
+
+} options_t;
+
+struct params
+{
+    options_t* opt;
+    char buffer[BUFLEN + 1];
+    int buflen;
+    int cs;
+};
+
+
+#line 70 "usage.rl"
+
+
+
+#line 40 "usage.rl.h"
+static const char _params_actions[] = {
+	0, 1, 0, 1, 3, 1, 4, 1, 
+	5, 1, 6, 2, 1, 7, 2, 1, 
+	8, 2, 1, 9, 2, 1, 10, 2, 
+	1, 11, 2, 2, 0
+};
+
+static const char _params_key_offsets[] = {
+	0, 0, 4, 6, 7, 8, 9, 10, 
+	11, 12, 13, 14, 15, 16, 17, 18, 
+	19, 20, 21, 22, 23, 24, 25, 26, 
+	27, 28, 29, 30, 31, 32, 33, 34, 
+	35, 36, 37, 38, 39, 40, 41, 42
+};
+
+static const char _params_trans_keys[] = {
+	45, 100, 102, 112, 45, 104, 104, 101, 
+	108, 112, 0, 101, 108, 116, 97, 0, 
+	0, 0, 0, 0, 0, 0, 114, 111, 
+	109, 114, 100, 105, 102, 102, 0, 0, 
+	0, 97, 116, 99, 104, 0, 0, 0, 
+	0, 0, 0
+};
+
+static const char _params_single_lengths[] = {
+	0, 4, 2, 1, 1, 1, 1, 1, 
+	1, 1, 1, 1, 1, 1, 1, 1, 
+	1, 1, 1, 1, 1, 1, 1, 1, 
+	1, 1, 1, 1, 1, 1, 1, 1, 
+	1, 1, 1, 1, 1, 1, 1, 0
+};
+
+static const char _params_range_lengths[] = {
+	0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0
+};
+
+static const char _params_index_offsets[] = {
+	0, 0, 5, 8, 10, 12, 14, 16, 
+	18, 20, 22, 24, 26, 28, 30, 32, 
+	34, 36, 38, 40, 42, 44, 46, 48, 
+	50, 52, 54, 56, 58, 60, 62, 64, 
+	66, 68, 70, 72, 74, 76, 78, 80
+};
+
+static const char _params_trans_targs[] = {
+	2, 8, 19, 30, 0, 3, 7, 0, 
+	4, 0, 5, 0, 6, 0, 7, 0, 
+	39, 0, 9, 0, 10, 0, 11, 0, 
+	12, 0, 13, 0, 0, 14, 15, 14, 
+	0, 16, 17, 16, 0, 18, 39, 18, 
+	20, 0, 21, 0, 22, 0, 23, 0, 
+	24, 0, 25, 0, 26, 0, 27, 0, 
+	28, 0, 0, 29, 17, 29, 31, 0, 
+	32, 0, 33, 0, 34, 0, 35, 0, 
+	0, 36, 37, 36, 0, 38, 17, 38, 
+	0, 0
+};
+
+static const char _params_trans_actions[] = {
+	0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 
+	9, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 3, 0, 0, 26, 17, 1, 
+	0, 26, 20, 1, 0, 26, 11, 1, 
+	0, 0, 0, 0, 0, 0, 0, 0, 
+	0, 0, 0, 0, 0, 0, 0, 0, 
+	5, 0, 0, 26, 14, 1, 0, 0, 
+	0, 0, 0, 0, 0, 0, 7, 0, 
+	0, 26, 17, 1, 0, 26, 23, 1, 
+	0, 0
+};
+
+static const int params_start = 1;
+static const int params_first_final = 39;
+static const int params_error = 0;
+
+static const int params_en_main = 1;
+
+
+#line 73 "usage.rl"
+
+static void params_init(struct params *fsm, options_t* opt)
+{
+    memset(opt, 0, sizeof(options_t));
+
+    fsm->opt = opt;
+    fsm->buflen = 0;
+    
+
+    
+#line 131 "usage.rl.h"
+	{
+	 fsm->cs = params_start;
+	}
+
+#line 83 "usage.rl"
+}
+
+static void params_execute(struct params *fsm, const char *data, int len)
+{
+    const char *p = data;
+    const char *pe = data + len;
+
+    
+#line 141 "usage.rl.h"
+	{
+	int _klen;
+	unsigned int _trans;
+	const char *_acts;
+	unsigned int _nacts;
+	const char *_keys;
+
+	if ( p == pe )
+		goto _test_eof;
+	if (  fsm->cs == 0 )
+		goto _out;
+_resume:
+	_keys = _params_trans_keys + _params_key_offsets[ fsm->cs];
+	_trans = _params_index_offsets[ fsm->cs];
+
+	_klen = _params_single_lengths[ fsm->cs];
+	if ( _klen > 0 ) {
+		const char *_lower = _keys;
+		const char *_mid;
+		const char *_upper = _keys + _klen - 1;
+		while (1) {
+			if ( _upper < _lower )
+				break;
+
+			_mid = _lower + ((_upper-_lower) >> 1);
+			if ( (*p) < *_mid )
+				_upper = _mid - 1;
+			else if ( (*p) > *_mid )
+				_lower = _mid + 1;
+			else {
+				_trans += (unsigned int)(_mid - _keys);
+				goto _match;
+			}
+		}
+		_keys += _klen;
+		_trans += _klen;
+	}
+
+	_klen = _params_range_lengths[ fsm->cs];
+	if ( _klen > 0 ) {
+		const char *_lower = _keys;
+		const char *_mid;
+		const char *_upper = _keys + (_klen<<1) - 2;
+		while (1) {
+			if ( _upper < _lower )
+				break;
+
+			_mid = _lower + (((_upper-_lower) >> 1) & ~1);
+			if ( (*p) < _mid[0] )
+				_upper = _mid - 2;
+			else if ( (*p) > _mid[1] )
+				_lower = _mid + 2;
+			else {
+				_trans += (unsigned int)((_mid - _keys)>>1);
+				goto _match;
+			}
+		}
+		_trans += _klen;
+	}
+
+_match:
+	 fsm->cs = _params_trans_targs[_trans];
+
+	if ( _params_trans_actions[_trans] == 0 )
+		goto _again;
+
+	_acts = _params_actions + _params_trans_actions[_trans];
+	_nacts = (unsigned int) *_acts++;
+	while ( _nacts-- > 0 )
+	{
+		switch ( *_acts++ )
+		{
+	case 0:
+#line 41 "usage.rl"
+	{
+        if (fsm->buflen < BUFLEN)
+            fsm->buffer[fsm->buflen++] = (*p);
+    }
+	break;
+	case 1:
+#line 46 "usage.rl"
+	{
+        if (fsm->buflen < BUFLEN)
+            fsm->buffer[fsm->buflen++] = 0;
+    }
+	break;
+	case 2:
+#line 51 "usage.rl"
+	{ fsm->buflen = 0; }
+	break;
+	case 3:
+#line 53 "usage.rl"
+	{ fsm->opt->delta = 1; }
+	break;
+	case 4:
+#line 54 "usage.rl"
+	{ fsm->opt->fromrdiff = 1; }
+	break;
+	case 5:
+#line 55 "usage.rl"
+	{ fsm->opt->patch = 1; }
+	break;
+	case 6:
+#line 56 "usage.rl"
+	{ fsm->opt->help = 1; }
+	break;
+	case 7:
+#line 58 "usage.rl"
+	{ fsm->opt->output_file = strdup(fsm->buffer); }
+	break;
+	case 8:
+#line 59 "usage.rl"
+	{ fsm->opt->rdiff_file = strdup(fsm->buffer); }
+	break;
+	case 9:
+#line 60 "usage.rl"
+	{ fsm->opt->source_file = strdup(fsm->buffer); }
+	break;
+	case 10:
+#line 61 "usage.rl"
+	{ fsm->opt->target_file = strdup(fsm->buffer); }
+	break;
+	case 11:
+#line 62 "usage.rl"
+	{ fsm->opt->umdiff_file = strdup(fsm->buffer); }
+	break;
+#line 255 "usage.rl.h"
+		}
+	}
+
+_again:
+	if (  fsm->cs == 0 )
+		goto _out;
+	if ( ++p != pe )
+		goto _resume;
+	_test_eof: {}
+	_out: {}
+	}
+
+#line 91 "usage.rl"
+}
+
+static int params_finish(struct params *fsm)
+{
+    if (fsm->cs == params_error)
+        return -1;
+    if (fsm->cs >= params_first_final)
+        return 1;
+    return 0;
+}
+
+static void show_usage()
+{
+    fprintf(stdout, "umdiff - Generate patch files for use with umd-livepatch\n");
+    fprintf(stdout, "\n");
+    fprintf(stdout, "Usage:\n");
+    fprintf(stdout, "  umdiff delta <source_file> <target_file> <output_file>\n");
+    fprintf(stdout, "  umdiff patch <source_file> <umdiff_file> <output_file>\n");
+    fprintf(stdout, "  umdiff from-rdiff <rdiff_file> <output_file>\n");
+    fprintf(stdout, "  umdiff --help\n");
+    fprintf(stdout, "\n");
+    fprintf(stdout, "Options:\n");
+    fprintf(stdout, "  -h --help  Prints a short usage summary.\n");
+    fprintf(stdout, "\n");
+}
+
+static int parse_options(int argc, char **argv, options_t* options)
+{
+    int a;
+    struct params params;
+
+    params_init(&params, options);
+    for (a = 1; a < argc; a++ )
+        params_execute(&params, argv[a], strlen(argv[a]) + 1);
+    if (params_finish(&params) != 1)
+    {
+        fprintf(stderr, "Error processing arguments\n");
+        show_usage();
+        return -1;
+    }
+
+    return 0;
+}
+