diff --git a/tools/fileadder.c b/tools/fileadder.c
index e027b54..3462ea0 100644
--- a/tools/fileadder.c
+++ b/tools/fileadder.c
@@ -16,7 +16,7 @@
 
 // Use a 4MB buffer, the same as the flash rom size
 #define BUFFER_SIZE 0x400000
-unsigned char buffer[BUFFER_SIZE];
+char buffer[BUFFER_SIZE];
 FILE *inptr, *dataptr, *ofile;
 int outptr;
 #define PATH_SIZE 1024
@@ -25,8 +25,14 @@ int outptr;
 char pathbuffer[PATH_SIZE];
 char ibuf[INDEX_SIZE];
 char dbuf[DEF_SIZE];
+char fbuf[DEF_SIZE];
+char xbuf[DEF_SIZE];
 int defbuf_p;
 int ibuf_p;
+int fbuf_p;
+int xbuf_p;
+bool addsDir = false;
+int callNum = 0;
 
 const char *argp_program_version = "fileadder 0.1";
 const char *argp_program_bug_address = "<git@logicog.de>";
@@ -125,10 +131,55 @@ int addidx(const char *name, int addr, int len)
 
 	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "#define FDATA_START_%s 0x%x\n", s, addr);
 	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "#define FDATA_SIZE_%s %d\n", s, len);
-	ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "  {\"%s\", FDATA_START_%s, FDATA_SIZE_%s},\n", name, s, s);
+	ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "  {\"/%s\", FDATA_START_%s, FDATA_SIZE_%s},\n", name, s, s);
+	if (!strcmp(name, "index.html"))
+		ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "  {\"/\", FDATA_START_%s, FDATA_SIZE_%s},\n", s, s);
 	return 0;
 }
 
+/*
+ * Replaces calls of the type #{function} in .html files being added
+ * It is assumed that the possibly expanded string will fit into the buffer
+ * Returns the new length of the string
+ */
+int replaceCalls(int pos)
+{
+	int i = 0;
+	char function_buf[256];
+
+	while (buffer[pos + i]) {
+		if ((buffer[pos + i]) == '#' && (buffer[pos + i + 1] == '{')) {
+			int j = 2;
+			while (buffer[pos + i + j]) {
+				if (buffer[pos + i + j] == '}')
+					break;
+				function_buf[j - 2] = buffer[pos + i + j];
+				j++;
+				if (j >= 255) {
+					function_buf[255] = '\0';
+					fprintf(stderr, "Function not terminated %s ", function_buf);
+					exit(5);
+				}
+
+			}
+			function_buf[j - 2] = '\0';
+			if (!buffer[pos + i + j])
+				return i + j;
+			// Because the buffers overlap we cannot use strcpy
+			memmove(&buffer[pos + i + 5], &buffer[pos + i + j], strlen(&buffer[pos + i + j]) + 1);
+			sprintf(&buffer[pos + i + 2], "%03d", callNum);
+			buffer[pos + i + 5] = '}';
+			i += 6;
+			fbuf_p += snprintf(&fbuf[fbuf_p], DEF_SIZE - fbuf_p, "  %s,\n", function_buf);
+			xbuf_p += snprintf(&xbuf[xbuf_p], DEF_SIZE - xbuf_p, "extern uint16_t %s(void);\n", function_buf);
+			callNum++;
+		}
+		i++;
+	}
+
+	return strlen(&buffer[pos]);
+}
+
 
 int main(int argc, char **argv)
 {
@@ -180,18 +231,20 @@ int main(int argc, char **argv)
 	}
 
 	// Add preambles to index and header file
-	defbuf_p = ibuf_p = 0;
+	defbuf_p = ibuf_p = xbuf_p = fbuf_p = 0;
 	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "#ifndef FDATA_DEFS_H\n\n");
 	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "#define FDATA_DEFS_H\n\n");
 	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "#include <stdint.h>\n\n");
-	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "struct f_data {\n  char *file;\n  uint32_t start;\n  uint16_t end;\n};\n\n");
+	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "struct f_data {\n  __code char *file;\n  uint32_t start;\n  uint16_t len;\n};\n\n");
+	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "typedef uint16_t (*fcall_ptr)(void);\n\n");
 
 	ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "// This file is automatically generated, do not edit!\n\n");
 	if (arguments.prefix)
 		ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "#include \"%s.h\"\n\n", arguments.prefix);
 	if (arguments.bank)
 		ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "#pragma codeseg %s\n", arguments.bank);
-	ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "struct f_data f_data[] = {\n");
+	ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "__code struct f_data f_data[] = {\n");
+	fbuf_p += snprintf(&fbuf[fbuf_p], DEF_SIZE - fbuf_p, "\n__code fcall_ptr f_calls[] = {\n");
 
 	// Now that the beginning of the buffer is filled with out image, optionally resize the image
 	if (filesize)
@@ -199,6 +252,7 @@ int main(int argc, char **argv)
 
 	if (stat(arguments.data_file, &s) == 0 && s.st_mode & S_IFDIR) {
 		printf("Adding entries in directory %s\n", arguments.data_file);
+		addsDir = true;
 		DIR *dirptr = opendir(arguments.data_file);
 		if (!dirptr) {
 			fprintf(stderr, "%s: ", arguments.data_file);
@@ -223,6 +277,10 @@ int main(int argc, char **argv)
 					buffer[arguments.address + data_read++ + 1] = '0';
 				printf("Data inserted from %s at 0x%x, size: %ld\n", pathbuffer, addr, data_read);
 			}
+			int old_len = data_read;
+			data_read = replaceCalls(addr);
+			if (old_len > data_read)
+				memset(buffer + addr + data_read, 0, old_len - data_read);
 			addidx(in_file->d_name, addr, data_read);
 			addr += data_read;
 		}
@@ -236,7 +294,8 @@ int main(int argc, char **argv)
 		}
 	}
 
-	ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "};\n");
+	ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "  {0, 0, 0}\n};\n");
+	fbuf_p += snprintf(&fbuf[fbuf_p], DEF_SIZE - fbuf_p, "};\n");
 	defbuf_p += snprintf(&dbuf[defbuf_p], DEF_SIZE - defbuf_p, "#endif\n");
 
 	if (filesize) {
@@ -280,10 +339,14 @@ int main(int argc, char **argv)
 			return 5;
 		}
 		fputs(ibuf, ofile);
+		fputs(xbuf, ofile);
+		fputs(fbuf, ofile);
 		fclose(ofile);
-	} else {
+	} else if (addsDir){
 		puts(dbuf);
+		puts(xbuf);
 		puts(ibuf);
+		puts(fbuf);
 	}
 	return 0;
 }