diff --git a/radio.c b/radio.c
index 56799ce..e5b7e00 100644
--- a/radio.c
+++ b/radio.c
@@ -71,90 +71,6 @@ void set_active_device(radio_device_t* d) {
 
 unsigned char radio_mem [1024*1024*2];  // Radio memory contents, up to 2 Mbytes
 
-//
-// Read firmware image from the binary file.
-//
-radio_device_t* radio_read_image(const char *filename)
-{
-    FILE *img;
-    struct stat st;
-    char ident[8];
-    radio_device_t * dev = NULL;
-
-    fprintf(stderr, "Read codeplug from file '%s'.\n", filename);
-    img = fopen(filename, "rb");
-    if (! img) {
-        perror(filename);
-        exit(-1);
-    }
-
-    // Guess device type by file size.
-    if (stat(filename, &st) < 0) {
-        perror(filename);
-        exit(-1);
-    }
-    switch (st.st_size) {
-    case 851968:
-    case 852533:
-        dev = &radio_uv380;
-        break;
-    case 262144:
-    case 262709:
-        dev = &radio_md380;
-        break;
-    case 1606528:
-        if (fread(ident, 1, 8, img) != 8) {
-            fprintf(stderr, "%s: Cannot read header.\n", filename);
-            exit(-1);
-        }
-        fseek(img, 0, SEEK_SET);
-        if (memcmp(ident, "D868UVE", 7) == 0) {
-            dev = &radio_d868uv;
-        } else if (memcmp(ident, "D878UV", 6) == 0) {
-            dev = &radio_d878uv;
-        } else if (memcmp(ident, "D6X2UV", 6) == 0) {
-            dev = &radio_dmr6x2;
-        } else {
-            fprintf(stderr, "%s: Unrecognized header '%.6s'\n",
-                filename, ident);
-            exit(-1);
-        }
-        break;
-    case 131072:
-        if (fread(ident, 1, 8, img) != 8) {
-            fprintf(stderr, "%s: Cannot read header.\n", filename);
-            exit(-1);
-        }
-        if (memcmp(ident, "BF-5R", 5) == 0) {
-            dev = &radio_rd5r;
-        } else if (memcmp(ident, "MD-760P", 7) == 0) {
-            dev = &radio_gd77;
-        } else if (memcmp(ident, "1801", 4) == 0) {
-            dev = &radio_dm1801;
-        } else if (memcmp(ident, "MD-760", 6) == 0) {
-            fprintf(stderr, "Old Radioddity GD-77 v2.6 image not supported!\n");
-            exit(-1);
-        } else {
-            fprintf(stderr, "%s: Unrecognized header '%.6s'\n",
-                filename, ident);
-            exit(-1);
-        }
-        fseek(img, 0, SEEK_SET);
-        break;
-    default:
-        fprintf(stderr, "%s: Unrecognized file size %u bytes.\n",
-            filename, (int) st.st_size);
-        exit(-1);
-    }
-
-
-    dev->read_image(dev, img);
-    fclose(img);
-
-    set_active_device(dev);
-    return dev;
-}
-
 //
 // Read the configuration from text file, and modify the firmware.
 //
diff --git a/src/radio.rs b/src/radio.rs
index eba845b..1504b34 100644
--- a/src/radio.rs
+++ b/src/radio.rs
@@ -37,7 +37,6 @@ extern {
   fn set_active_device(device: *const radio_device_t);
 
   fn radio_print_config(device: *const radio_device_t, file: *const libc::FILE, verbose: c_int);
-  fn radio_read_image(filename: *const c_char) -> *const radio_device_t;
   fn radio_parse_config(device: *const radio_device_t, filename: *const c_char);
   fn radio_write_csv(device: *const radio_device_t, filename: *const c_char);
 
@@ -189,38 +188,98 @@ pub fn verify_config(radio: &Radio) {
 
 /// Read firmware image from the binary file.
 pub fn read_image(filename: &str) -> Radio {
+  use std::io::{Seek, SeekFrom, Read};
 
-  /*
-  eprintln!"Read codeplug from file '{}'.", filename);
+  fn read_header(file: &mut std::fs::File, filename: &str) -> Vec<u8> {
+      let mut header_buf: [u8; 7] = [0; 7];
+      match file.read(&mut header_buf) {
+        Ok(7) => (),
+        Ok(_) => {
+          eprintln!("{}: Cannot read header.", filename);
+          exit(-1);
+        },
+        Err(e) => {
+          eprintln!("{}: Cannot read header. Error: {}", filename, e);
+          exit(-1);
+        }
+      };
 
-  let img = std::fs::File::open(filename).unwrap();
+      file.seek(SeekFrom::Start(0)).unwrap();
+
+      header_buf.to_vec()
+  }
+
+  eprintln!("Read codeplug from file '{}'.", filename);
+
+  let mut img_file = std::fs::File::open(filename).unwrap();
   let metadata = std::fs::metadata(filename).unwrap();
   let file_size = metadata.len();
-  match file_size {
-    851968 | 852533 => {
 
+  let device = unsafe {match file_size {
+    851968 | 852533 => {
+      &radio_uv380
     }
     262144 | 262709 => {
-
+      &radio_md380
     }
     1606528 => {
+      let header = read_header(&mut img_file, filename);
+      if header.as_slice().starts_with(b"D868UVE") {
+        &radio_d868uv
+      } else if header.as_slice().starts_with(b"D878UV") {
+        &radio_d878uv
+      } else if header.as_slice().starts_with(b"D6X2UV") {
+        &radio_dmr6x2
+      } else {
+        match std::str::from_utf8(&header) {
+          Ok(s) => eprintln!("Unrecognized header: {}", s),
+          Err(_) => eprintln!("Unrecognized header: {:?}", header),
+        };
 
+        exit(-1)
+      }
     }
     131072 => {
+      let header = read_header(&mut img_file, filename);
+      if header.as_slice().starts_with(b"BF-5R") {
+        &radio_rd5r
+      } else if header.as_slice().starts_with(b"MD-760P") {
+        &radio_gd77
+      } else if header.as_slice().starts_with(b"1801") {
+        &radio_dm1801
+      } else if header.as_slice().starts_with(b"MD-760") {
+        eprintln!("Old Radioddity GD-77 v2.6 image not supported!");
+        exit(-1)
+      } else {
+        match std::str::from_utf8(&header) {
+          Ok(s) => eprintln!("Unrecognized header: {}", s),
+          Err(_) => eprintln!("Unrecognized header: {:?}", header),
+        };
 
+        exit(-1)
+
+      }
     }
     size => {
       eprintln!("{}: Unrecognized file size {} bytes.", filename, size);
-      exit(-1);
+      exit(-1)
     }
-  };
-  */
+  } };
+
+  let fd = img_file.as_raw_fd();
+  let mode = CString::new("rb").unwrap();
+  unsafe {
+    let device = device as *const radio_device_t;
+    let device = device as *mut radio_device_t;
+    let file = libc::fdopen(fd, mode.as_ptr());
+    let read_image_fn = (*device).read_image.unwrap();
+
+    read_image_fn(device, file);
+    libc::fclose(file);
+    set_active_device(device);
+    Radio { ptr: device }
+  }
 
-  let filename = CString::new(filename.to_string()).unwrap();
-  let ptr = unsafe {
-    radio_read_image(filename.as_ptr())
-  };
-  Radio { ptr: ptr as *mut radio_device_t }
 }
 
 /// Save firmware image to the binary file.