AP_IOMCU: fixed repeated upload of IO fw

libraries/AP_IOMCU/AP_IOMCU.cpp

@@ -651,11 +651,10 @@ bool AP_IOMCU::check_crc(void)
     }
     uint32_t crc = crc_crc32(0, fw, fw_size);
 
-    // pad to max size
-	while (fw_size < flash_size) {
+    // pad CRC to max size
+	for (uint32_t i=0; i<flash_size-fw_size; i++) {
 		uint8_t b = 0xff;
 		crc = crc_crc32(crc, &b, 1);
-		fw_size++;
 	}
 
     uint32_t io_crc = 0;

libraries/AP_IOMCU/fw_uploader.cpp

@@ -383,10 +383,9 @@ bool AP_IOMCU::verify_rev3(uint32_t fw_size_local)
 {
     bool ret;
     uint32_t sum = 0;
-    uint32_t bytes_read = 0;
     uint32_t crc = 0;
     uint32_t fw_size_remote;
-    uint8_t fill_blank = 0xff;
+    const uint8_t fill_blank = 0xff;
 
     debug("verify...");
 
@@ -398,23 +397,11 @@ bool AP_IOMCU::verify_rev3(uint32_t fw_size_local)
         return ret;
     }
 
-    /* read through the firmware file again and calculate the checksum */
-    while (bytes_read < fw_size_local) {
-        uint32_t n = fw_size_local - bytes_read;
-        if (n > 4) {
-            n = 4;
-        }
-
-        /* calculate crc32 sum */
-        sum = crc_crc32(sum, &fw[bytes_read], n);
-
-        bytes_read += n;
-    }
+    sum = crc_crc32(0, fw, fw_size_local);
 
-    /* fill the rest with 0xff */
-    while (bytes_read < fw_size_remote) {
+    /* fill the rest of CRC with 0xff */
+    for (uint32_t i=0; i<fw_size_remote - fw_size_local; i++) {
         sum = crc_crc32(sum, &fill_blank, 1);
-        bytes_read++;
     }
 
     /* request CRC from IO */