diff --git a/targets/stm32l442/Makefile b/targets/stm32l442/Makefile
index 00a24cf..0497aa0 100644
--- a/targets/stm32l442/Makefile
+++ b/targets/stm32l442/Makefile
@@ -14,11 +14,20 @@ flash: solo.hex bootloader.hex
 	STM32_Programmer_CLI -c port=SWD -halt -e all --readunprotect
 	STM32_Programmer_CLI -c port=SWD -halt  -d all.hex -rst
 
+flash_dfu: solo.hex bootloader.hex
+	python merge_hex.py solo.hex bootloader.hex all.hex
+	# STM32_Programmer_CLI -c port=usb1 -halt -e all --readunprotect
+	STM32_Programmer_CLI -c port=usb1 -halt  -d all.hex
+
 flashboot: solo.hex bootloader.hex
 	python merge_hex.py solo.hex bootloader.hex all.hex
 	STM32_Programmer_CLI -c port=SWD -halt -e all --readunprotect
 	STM32_Programmer_CLI -c port=SWD -halt  -d bootloader.hex -rst
 
+# tell ST DFU to enter application
+detach:
+	STM32_Programmer_CLI -c port=usb1 -ob nBOOT0=1
+
 bootloader.hex:
 	echo "You need to build the bootloader first."
 
diff --git a/targets/stm32l442/application.mk b/targets/stm32l442/application.mk
index 4ee26e3..3226826 100644
--- a/targets/stm32l442/application.mk
+++ b/targets/stm32l442/application.mk
@@ -70,8 +70,6 @@ all: $(TARGET).elf
 clean:
 	rm -f *.o src/*.o src/*.elf  bootloader/*.o $(OBJ)
 
-detach:
-	STM32_Programmer_CLI -c port=usb1 -ob nBOOT0=1
 
 cbor:
 	cd ../../tinycbor/ && make clean
diff --git a/targets/stm32l442/bootloader/bootloader.c b/targets/stm32l442/bootloader/bootloader.c
index 41ef628..8239014 100644
--- a/targets/stm32l442/bootloader/bootloader.c
+++ b/targets/stm32l442/bootloader/bootloader.c
@@ -63,6 +63,7 @@ int is_authorized_to_boot()
 int bootloader_bridge(int klen, uint8_t * keyh)
 {
     static int has_erased = 0;
+    int i;
     BootloaderReq * req =  (BootloaderReq *  )keyh;
     uint8_t hash[32];
     uint8_t version = 1;
@@ -103,6 +104,8 @@ int bootloader_bridge(int klen, uint8_t * keyh)
             }
 
             flash_write((uint32_t)ptr,req->payload, len);
+
+
             break;
         case BootDone:
             printf1(TAG_BOOT, "BootDone: ");
@@ -149,7 +152,7 @@ int bootloader_bridge(int klen, uint8_t * keyh)
             printf1(TAG_BOOT, "BootReboot.\r\n");
             device_reboot();
             break;
-#ifndef SOLO_HACKER
+#ifdef SOLO_HACKER
         case BootBootloader:
             printf1(TAG_BOOT, "BootBootloader.\r\n");
             flash_option_bytes_init(1);
diff --git a/targets/stm32l442/src/flash.c b/targets/stm32l442/src/flash.c
index 63f6f7a..5d7e463 100644
--- a/targets/stm32l442/src/flash.c
+++ b/targets/stm32l442/src/flash.c
@@ -139,6 +139,39 @@ void flash_write(uint32_t addr, uint8_t * data, size_t sz)
 
 }
 
+// NOT YET working
+void flash_write_fast(uint32_t addr, uint32_t * data)
+{
+    __disable_irq();
+    while (FLASH->SR & (1<<16))
+        ;
+    FLASH->SR = FLASH->SR;
+
+    // Select fast program action
+    FLASH->CR |= (1<<18);
+
+    int i;
+    for(i = 0; i < 64; i++)
+    {
+        *(volatile uint32_t*)addr = (*data);
+        addr+=4;
+        data++;
+    }
+
+    while (FLASH->SR & (1<<16))
+        ;
+
+    if(FLASH->SR & (1<<1))
+    {
+        printf2(TAG_ERR,"program NOT successful %lx\r\n", FLASH->SR);
+    }
+
+    FLASH->SR = (1<<0);
+    FLASH->CR &= ~(1<<18);
+    __enable_irq();
+
+}
+
 void flash_lock()
 {
     FLASH->CR |= (1U<<31);
diff --git a/targets/stm32l442/src/flash.h b/targets/stm32l442/src/flash.h
index f099700..9838ff8 100644
--- a/targets/stm32l442/src/flash.h
+++ b/targets/stm32l442/src/flash.h
@@ -4,6 +4,7 @@
 void flash_erase_page(uint8_t page);
 void flash_write_dword(uint32_t addr, uint64_t data);
 void flash_write(uint32_t addr, uint8_t * data, size_t sz);
+void flash_write_fast(uint32_t addr, uint32_t * data);
 void flash_option_bytes_init(int boot_from_dfu);
 
 #define FLASH_PAGE_SIZE     2048
diff --git a/tools/programmer.py b/tools/programmer.py
index 2611d0b..915018a 100644
--- a/tools/programmer.py
+++ b/tools/programmer.py
@@ -142,11 +142,21 @@ class Programmer():
         this command will tell the token to boot directly to the st DFU
         so it can be reprogrammed.  Warning, you could brick your device.
         """
-        if self.exchange == self.exchange_hid:
-            self.send_only_hid(SoloBootloader.HIDCommandEnterSTBoot, '')
-        else:
+        soloboot = False
+        try:
+            p.version()
+            soloboot = True
+        except CtapError as e:
+            if e.code == CtapError.ERR.INVALID_COMMAND:
+                pass
+            else:
+                raise (e)
+
+        if soloboot or self.exchange == self.exchange_u2f:
             req = Programmer.format_request(SoloBootloader.st_dfu)
             self.send_only_hid(SoloBootloader.HIDCommandBoot, req)
+        else:
+            self.send_only_hid(SoloBootloader.HIDCommandEnterSTBoot, '')
 
     def program_file(self,name):
 
@@ -235,7 +245,7 @@ if __name__ == '__main__':
     parser.add_argument("--reset-only", action="store_true", help = 'Don\'t write anything, try to boot without a signature.')
     parser.add_argument("--reboot", action="store_true", help = 'Tell bootloader to reboot.')
     parser.add_argument("--enter-bootloader", action="store_true", help = 'Don\'t write anything, try to enter bootloader.  Typically only supported by Solo Hacker builds.')
-    parser.add_argument("--st-dfu", action="store_true", help = 'Don\'t write anything, try to enter ST DFU.  Warning, you could brick your Solo if you overwrite everything.  Make sure to reprogram the option bytes just to be safe.')
+    parser.add_argument("--st-dfu", action="store_true", help = 'Don\'t write anything, try to enter ST DFU.  Warning, you could brick your Solo if you overwrite everything.  You should reprogram the option bytes just to be safe (boot to Solo bootloader first, then run this command).')
     args = parser.parse_args()
     print()