diff --git a/.gitignore b/.gitignore
index 7d4f050..995fa2c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 rpiboot
+bin2c
diff --git a/fmemopen.c b/fmemopen.c
new file mode 100644
index 0000000..db88799
--- /dev/null
+++ b/fmemopen.c
@@ -0,0 +1,107 @@
+//
+// Copyright 2011-2014 NimbusKit
+// Originally ported from https://github.com/ingenuitas/python-tesseract/blob/master/fmemopen.c
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+struct fmem {
+  size_t pos;
+  size_t size;
+  char *buffer;
+};
+typedef struct fmem fmem_t;
+
+static int readfn(void *handler, char *buf, int size) {
+  fmem_t *mem = handler;
+  size_t available = mem->size - mem->pos;
+
+  if (size > (int)available) {
+    size = available;
+  }
+  memcpy(buf, mem->buffer + mem->pos, sizeof(char) * size);
+  mem->pos += size;
+
+  return size;
+}
+
+static int writefn(void *handler, const char *buf, int size) {
+  fmem_t *mem = handler;
+  size_t available = mem->size - mem->pos;
+
+  if (size > (int)available) {
+    size = available;
+  }
+  memcpy(mem->buffer + mem->pos, buf, sizeof(char) * size);
+  mem->pos += size;
+
+  return size;
+}
+
+static fpos_t seekfn(void *handler, fpos_t offset, int whence) {
+  size_t pos;
+  fmem_t *mem = handler;
+
+  switch (whence) {
+    case SEEK_SET: {
+      if (offset >= 0) {
+        pos = (size_t)offset;
+      } else {
+        pos = 0;
+      }
+      break;
+    }
+    case SEEK_CUR: {
+      if (offset >= 0 || (size_t)(-offset) <= mem->pos) {
+        pos = mem->pos + (size_t)offset;
+      } else {
+        pos = 0;
+      }
+      break;
+    }
+    case SEEK_END: pos = mem->size + (size_t)offset; break;
+    default: return -1;
+  }
+
+  if (pos > mem->size) {
+    return -1;
+  }
+
+  mem->pos = pos;
+  return (fpos_t)pos;
+}
+
+static int closefn(void *handler) {
+  free(handler);
+  return 0;
+}
+
+FILE *fmemopen(void *buf, size_t size, const char *mode) {
+  #pragma unused(mode)
+  // This data is released on fclose.
+  fmem_t* mem = (fmem_t *) malloc(sizeof(fmem_t));
+
+  // Zero-out the structure.
+  memset(mem, 0, sizeof(fmem_t));
+
+  mem->size = size;
+  mem->buffer = buf;
+
+  // funopen's man page: https://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man3/funopen.3.html
+  return funopen(mem, readfn, writefn, seekfn, closefn);
+}
diff --git a/main.c b/main.c
index bae94bc..3d9bb3b 100644
--- a/main.c
+++ b/main.c
@@ -8,13 +8,18 @@
 #include "msd/bootcode.h"
 #include "msd/start.h"
 
+/* Assume BSD without native fmemopen() if doesn't seem to be glibc */
+#if defined(__APPLE__) || !defined(_GNU_SOURCE) || !defined(_POSIX_C_SOURCE) || _POSIX_C_SOURCE < 200809L
+#include "fmemopen.c" // BSD fmemopen() compat in terms of funopen()
+#endif
+
 int signed_boot = 0;
 int verbose = 0;
 int loop = 0;
 int overlay = 0;
 long delay = 500;
 char * directory = NULL;
-char pathname[18];
+char pathname[18] = {0};
 uint8_t targetPortNo = 99;
 
 int out_ep;
@@ -413,7 +418,7 @@ FILE * check_file(char * dir, char *fname)
 	// Check directory first then /usr/share/rpiboot
 	if(dir)
 	{
-		if(overlay&&(pathname != NULL))
+		if(overlay&&(pathname[0] != 0))
 		{
 			strcpy(path, dir);
 			strcat(path, "/");
diff --git a/msd/.gitignore b/msd/.gitignore
new file mode 100644
index 0000000..424c745
--- /dev/null
+++ b/msd/.gitignore
@@ -0,0 +1 @@
+*.h