diff --git a/avr/bootloader/bootloader.c b/avr/bootloader/bootloader.c
index b09a1f6..874e184 100644
--- a/avr/bootloader/bootloader.c
+++ b/avr/bootloader/bootloader.c
@@ -33,6 +33,10 @@
 #include "config.h"
 #include "usbdrv/usbdrv.c"
 
+
+
+
+
 /*
  * USBasp requests, taken from the original USBasp sourcecode 
  */
@@ -74,6 +78,10 @@
                   (LED_DIR ^= (1 << LED_PIN)));}
 
 
+#define AVR_BTLDR_EN_PORT	    PORTC
+#define AVR_BTLDR_EN_DIR	    DDRC
+#define AVR_BTLDR_EN_PIN	    PC1
+#define AVR_BTLDR_EN_IN	        PINC
 
 
 /*
@@ -449,6 +457,18 @@ int __attribute__ ((noreturn, OS_main)) main(void)
     uint16_t delay = 0;
     timeout = TIMEOUT;
 
+    DDRC &= ~(1 << AVR_BTLDR_EN_PIN);	    
+    PORTC &= ~(1 << AVR_BTLDR_EN_PIN);	    
+
+    if ((AVR_BTLDR_EN_IN & ( 1 << AVR_BTLDR_EN_PIN)) == 0){
+        banner();
+        uart_puts("Bootloader flashing is disabled\n\r");
+        MCUSR = 0;
+        leave_bootloader();
+        
+    }
+    	    
+
 
     /*
      * if power-on reset, quit bootloader via watchdog reset 
diff --git a/avr/usbload/testing.c b/avr/usbload/testing.c
index 9657d67..38054d5 100644
--- a/avr/usbload/testing.c
+++ b/avr/usbload/testing.c
@@ -31,6 +31,7 @@
 #include "debug.h"
 #include "crc.h"
 #include "info.h"
+#include "dump.h"
 
 void test_read_write()
 {
@@ -92,6 +93,30 @@ void test_non_zero_memory(uint32_t bottom_addr, uint32_t top_addr)
 }
 
 
+void test_memory_pattern(uint32_t bottom_addr, uint32_t top_addr, uint32_t bank_size)
+{
+    uint32_t addr = 0;
+    uint8_t pattern = 0x55;
+    info_P(PSTR("test_memory_pattern: bottom_addr=0x%08lx top_addr=0x%08lx\n"), bottom_addr, top_addr);
+    sram_bulk_write_start(bottom_addr);
+    for (addr = bottom_addr; addr < top_addr; addr++) {
+        if (addr % bank_size == 0){
+            pattern++;
+            info_P(PSTR("test_memory_pattern: write addr=0x%08lx pattern=0x%08lx\n"), addr, pattern);
+        }
+        sram_bulk_write(pattern);
+    }
+    sram_bulk_write_end();
+
+
+    for (addr = bottom_addr; addr < top_addr; addr+=bank_size) {
+        info_P(PSTR("test_memory_pattern: dump bottom_addr=0x%08lx top_addr=0x%08lx\n"), addr, addr + bank_size);
+        dump_memory(addr, addr + bank_size );
+        info_P(PSTR("----------------------------------------------------------------\n"));
+    }
+
+    crc_check_bulk_memory((uint32_t)bottom_addr,top_addr, bank_size);
+}
 
 void test_crc()
 {