diff --git a/tools/fileadder.c b/tools/fileadder.c
index 3462ea0..89bbd73 100644
--- a/tools/fileadder.c
+++ b/tools/fileadder.c
@@ -118,6 +118,35 @@ int addfile(const char *name, int addr)
 }
 
 
+int hasSuffix(const char *str, const char *suffix)
+{
+    if (!str || !suffix)
+        return 0;
+
+    size_t lenstr = strlen(str);
+    size_t lensuffix = strlen(suffix);
+
+    if (lensuffix >  lenstr)
+        return 0;
+
+    return strncmp(str + lenstr - lensuffix, suffix, lensuffix) == 0;
+}
+
+
+char *getMime(const char *name)
+{
+	if (hasSuffix(name, ".html"))
+		return "text/html";
+	else if (hasSuffix(name, ".svg"))
+		return "image/svg+xml";
+	else if (hasSuffix(name, ".ico"))
+		return "image/svg+xml";
+	else if (hasSuffix(name, ".png"))
+		return "image/png";
+	return "text/plain";
+}
+
+
 int addidx(const char *name, int addr, int len)
 {
 	char s[256];
@@ -131,9 +160,9 @@ 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, \"%s\"},\n", name, s, s, getMime(name));
 	if (!strcmp(name, "index.html"))
-		ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "  {\"/\", FDATA_START_%s, FDATA_SIZE_%s},\n", s, s);
+		ibuf_p += snprintf(&ibuf[ibuf_p], INDEX_SIZE - ibuf_p, "  {\"/\", FDATA_START_%s, FDATA_SIZE_%s, \"text/html\"},\n", s, s);
 	return 0;
 }
 
@@ -235,7 +264,7 @@ int main(int argc, char **argv)
 	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  __code char *file;\n  uint32_t start;\n  uint16_t len;\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  __code char *mime;\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");
@@ -273,8 +302,10 @@ int main(int argc, char **argv)
 
 			size_t data_read = addfile(pathbuffer, addr);
 			if (data_read) {
-				if (arguments.add_zero)
-					buffer[arguments.address + data_read++ + 1] = '0';
+				if (arguments.add_zero) {
+					buffer[addr + data_read + 1] = '\0';
+					data_read++;
+				}
 				printf("Data inserted from %s at 0x%x, size: %ld\n", pathbuffer, addr, data_read);
 			}
 			int old_len = data_read;
@@ -288,8 +319,10 @@ int main(int argc, char **argv)
 		size_t data_read = addfile(arguments.data_file, arguments.address);
 
 		if (data_read) {
-			if (arguments.add_zero)
-				buffer[arguments.address + data_read++ + 1] = '0';
+			if (arguments.add_zero) {
+				buffer[arguments.address + data_read + 1] = '\0';
+				data_read++;
+			}
 			printf("Data inserted at 0x%x, size: %ld\n", arguments.address, data_read);
 		}
 	}