diff --git a/optiboot/bootloaders/optiboot/optiboot_x.c b/optiboot/bootloaders/optiboot/optiboot_x.c
index 224ab35..8138b62 100644
--- a/optiboot/bootloaders/optiboot/optiboot_x.c
+++ b/optiboot/bootloaders/optiboot/optiboot_x.c
@@ -330,8 +330,10 @@ int main(void) {
 #if LED_START_FLASHES > 0
     // Set up RTC counting at about 1/8s (input is 32kHz)
     RTC.CTRLA= RTC_PRESCALER_DIV4096_gc | RTC_RTCEN_bm;
+    RTC.DBGCTRL = 1; // enable during debug
 #endif
 
+    _PROTECTED_WRITE(CLKCTRL.MCLKCTRLB, 0);  // full speed clock
 
     MYUART_TXPORT.DIR |= MYUART_TXPIN; // set TX pin to output
     MYUART_TXPORT.OUT |= MYUART_TXPIN;  // and "1" as per datasheet
@@ -349,7 +351,7 @@ int main(void) {
 
 #if (LED_START_FLASHES > 0) || defined(LED_DATA_FLASH) || defined(LED_START_ON)
     /* Set LED pin as output */
-    LED_PORT.DIR |= _BV(LED);
+    LED_PORT.DIR |= LED;
 #endif
 
 #if LED_START_FLASHES > 0
@@ -358,7 +360,7 @@ int main(void) {
 #else
 #if defined(LED_START_ON)
     /* Turn on LED to indicate starting bootloader (less code!) */
-    LED_PORT.OUT |= _BV(LED);
+    LED_PORT.OUT |= LED;
 #endif
 #endif
 
@@ -486,15 +488,14 @@ void putch(char ch) {
 
 uint8_t getch(void) {
     uint8_t ch, flags;
-    while (!(MYUART.STATUS & USART_RXCIF_bm)) {
-	return (MYUART.RXDATAL);
-    }
+    while (!(MYUART.STATUS & USART_RXCIF_bm))
+	;
     flags = MYUART.RXDATAH;
     ch = MYUART.RXDATAL;
     if ((flags & USART_FERR_bm) == 0)
 	watchdogReset();
 #ifdef LED_DATA_FLASH
-    LED_PORT.IN |= _BV(LED);
+    LED_PORT.IN |= LED;
 #endif
 
     return ch;
@@ -518,14 +519,14 @@ void verifySpace() {
 void flash_led(uint8_t count) {
     uint8_t last;
     while (count--) {
-	LED_PORT.IN |= _BV(LED);
+	LED_PORT.IN |= LED;
 	last = RTC.CNTL & 1;
 	while ((RTC.CNTL & 1) == last) {
 	    watchdogReset();
 	    if (MYUART.STATUS & USART_RXCIF_bm)
 		return;
 	}
-    } while (--count);
+    }
 }
 #endif
 
diff --git a/optiboot/bootloaders/optiboot/pin_defs_x.h b/optiboot/bootloaders/optiboot/pin_defs_x.h
index 0f172a6..e7fffa6 100644
--- a/optiboot/bootloaders/optiboot/pin_defs_x.h
+++ b/optiboot/bootloaders/optiboot/pin_defs_x.h
@@ -199,411 +199,411 @@
 #define LED_NAME "B0"
 #undef LED
 #define LED_PORT    VPORTB
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == B1
 #define LED_NAME "B1"
 #undef LED
 #define LED_PORT    VPORTB
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == B2
 #define LED_NAME "B2"
 #undef LED
 #define LED_PORT    VPORTB
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == B3
 #define LED_NAME "B3"
 #undef LED
 #define LED_PORT    VPORTB
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == B4
 #define LED_NAME "B4"
 #undef LED
 #define LED_PORT    VPORTB
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == B5
 #define LED_NAME "B5"
 #undef LED
 #define LED_PORT    VPORTB
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == B6
 #define LED_NAME "B6"
 #undef LED
 #define LED_PORT    VPORTB
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == B7
 #define LED_NAME "B7"
 #undef LED
 #define LED_PORT    VPORTB
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == C0
 #define LED_NAME "C0"
 #undef LED
 #define LED_PORT    VPORTC
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == C1
 #define LED_NAME "C1"
 #undef LED
 #define LED_PORT    VPORTC
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == C2
 #define LED_NAME "C2"
 #undef LED
 #define LED_PORT    VPORTC
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == C3
 #define LED_NAME "C3"
 #undef LED
 #define LED_PORT    VPORTC
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == C4
 #define LED_NAME "C4"
 #undef LED
 #define LED_PORT    VPORTC
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == C5
 #define LED_NAME "C5"
 #undef LED
 #define LED_PORT    VPORTC
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == C6
 #define LED_NAME "C6"
 #undef LED
 #define LED_PORT    VPORTC
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == C7
 #define LED_NAME "C7"
 #undef LED
 #define LED_PORT    VPORTC
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == D0
 #define LED_NAME "D0"
 #undef LED
 #define LED_PORT    VPORTD
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == D1
 #define LED_NAME "D1"
 #undef LED
 #define LED_PORT    VPORTD
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == D2
 #define LED_NAME "D2"
 #undef LED
 #define LED_PORT    VPORTD
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == D3
 #define LED_NAME "D3"
 #undef LED
 #define LED_PORT    VPORTD
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == D4
 #define LED_NAME "D4"
 #undef LED
 #define LED_PORT    VPORTD
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == D5
 #define LED_NAME "D5"
 #undef LED
 #define LED_PORT    VPORTD
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == D6
 #define LED_NAME "D6"
 #undef LED
 #define LED_PORT    VPORTD
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == D7
 #define LED_NAME "D7"
 #undef LED
 #define LED_PORT    VPORTD
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == E0
 #define LED_NAME "E0"
 #undef LED
 #define LED_PORT    VPORTE
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == E1
 #define LED_NAME "E1"
 #undef LED
 #define LED_PORT    VPORTE
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == E2
 #define LED_NAME "E2"
 #undef LED
 #define LED_PORT    VPORTE
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == E3
 #define LED_NAME "E3"
 #undef LED
 #define LED_PORT    VPORTE
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == E4
 #define LED_NAME "E4"
 #undef LED
 #define LED_PORT    VPORTE
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == E5
 #define LED_NAME "E5"
 #undef LED
 #define LED_PORT    VPORTE
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == E6
 #define LED_NAME "E6"
 #undef LED
 #define LED_PORT    VPORTE
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == E7
 #define LED_NAME "E7"
 #undef LED
 #define LED_PORT    VPORTE
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == F0
 #define LED_NAME "F0"
 #undef LED
 #define LED_PORT    VPORTF
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == F1
 #define LED_NAME "F1"
 #undef LED
 #define LED_PORT    VPORTF
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == F2
 #define LED_NAME "F2"
 #undef LED
 #define LED_PORT    VPORTF
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == F3
 #define LED_NAME "F3"
 #undef LED
 #define LED_PORT    VPORTF
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == F4
 #define LED_NAME "F4"
 #undef LED
 #define LED_PORT    VPORTF
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == F5
 #define LED_NAME "F5"
 #undef LED
 #define LED_PORT    VPORTF
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == F6
 #define LED_NAME "F6"
 #undef LED
 #define LED_PORT    VPORTF
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == F7
 #define LED_NAME "F7"
 #undef LED
 #define LED_PORT    VPORTF
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == G0
 #define LED_NAME "G0"
 #undef LED
 #define LED_PORT    VPORTG
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == G1
 #define LED_NAME "G1"
 #undef LED
 #define LED_PORT    VPORTG
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == G2
 #define LED_NAME "G2"
 #undef LED
 #define LED_PORT    VPORTG
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == G3
 #define LED_NAME "G3"
 #undef LED
 #define LED_PORT    VPORTG
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == G4
 #define LED_NAME "G4"
 #undef LED
 #define LED_PORT    VPORTG
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == G5
 #define LED_NAME "G5"
 #undef LED
 #define LED_PORT    VPORTG
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == G6
 #define LED_NAME "G6"
 #undef LED
 #define LED_PORT    VPORTG
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == G7
 #define LED_NAME "G7"
 #undef LED
 #define LED_PORT    VPORTG
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == H0
 #define LED_NAME "H0"
 #undef LED
 #define LED_PORT    VPORTH
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == H1
 #define LED_NAME "H1"
 #undef LED
 #define LED_PORT    VPORTH
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == H2
 #define LED_NAME "H2"
 #undef LED
 #define LED_PORT    VPORTH
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == H3
 #define LED_NAME "H3"
 #undef LED
 #define LED_PORT    VPORTH
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == H4
 #define LED_NAME "H4"
 #undef LED
 #define LED_PORT    VPORTH
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == H5
 #define LED_NAME "H5"
 #undef LED
 #define LED_PORT    VPORTH
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == H6
 #define LED_NAME "H6"
 #undef LED
 #define LED_PORT    VPORTH
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == H7
 #define LED_NAME "H7"
 #undef LED
 #define LED_PORT    VPORTH
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == J0
 #define LED_NAME "J0"
 #undef LED
 #define LED_PORT    VPORTJ
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == J1
 #define LED_NAME "J1"
 #undef LED
 #define LED_PORT    VPORTJ
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == J2
 #define LED_NAME "J2"
 #undef LED
 #define LED_PORT    VPORTJ
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == J3
 #define LED_NAME "J3"
 #undef LED
 #define LED_PORT    VPORTJ
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == J4
 #define LED_NAME "J4"
 #undef LED
 #define LED_PORT    VPORTJ
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == J5
 #define LED_NAME "J5"
 #undef LED
 #define LED_PORT    VPORTJ
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == J6
 #define LED_NAME "J6"
 #undef LED
 #define LED_PORT    VPORTJ
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == J7
 #define LED_NAME "J7"
 #undef LED
 #define LED_PORT    VPORTJ
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == K0
 #define LED_NAME "K0"
 #undef LED
 #define LED_PORT    VPORTK
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == K1
 #define LED_NAME "K1"
 #undef LED
 #define LED_PORT    VPORTK
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == K2
 #define LED_NAME "K2"
 #undef LED
 #define LED_PORT    VPORTK
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == K3
 #define LED_NAME "K3"
 #undef LED
 #define LED_PORT    VPORTK
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == K4
 #define LED_NAME "K4"
 #undef LED
 #define LED_PORT    VPORTK
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == K5
 #define LED_NAME "K5"
 #undef LED
 #define LED_PORT    VPORTK
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == K6
 #define LED_NAME "K6"
 #undef LED
 #define LED_PORT    VPORTK
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == K7
 #define LED_NAME "K7"
 #undef LED
 #define LED_PORT    VPORTK
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == L0
 #define LED_NAME "L0"
 #undef LED
 #define LED_PORT    VPORTL
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == L1
 #define LED_NAME "L1"
 #undef LED
 #define LED_PORT    VPORTL
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == L2
 #define LED_NAME "L2"
 #undef LED
 #define LED_PORT    VPORTL
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == L3
 #define LED_NAME "L3"
 #undef LED
 #define LED_PORT    VPORTL
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == L4
 #define LED_NAME "L4"
 #undef LED
 #define LED_PORT    VPORTL
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == L5
 #define LED_NAME "L5"
 #undef LED
 #define LED_PORT    VPORTL
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == L6
 #define LED_NAME "L6"
 #undef LED
 #define LED_PORT    VPORTL
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == L7
 #define LED_NAME "L7"
 #undef LED
 #define LED_PORT    VPORTL
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #elif LED == A0
 #define LED_NAME "A0"
@@ -614,42 +614,42 @@
 #else
 #define LED_PORT    VPORTA
 #endif
-#define LED	    PORT0
+#define LED	    (1<<PORT0)
 #elif LED == A1
 #define LED_NAME "A1"
 #undef LED
 #define LED_PORT    VPORTA
-#define LED	    PORT1
+#define LED	    (1<<PORT1)
 #elif LED == A2
 #define LED_NAME "A2"
 #undef LED
 #define LED_PORT    VPORTA
-#define LED	    PORT2
+#define LED	    (1<<PORT2)
 #elif LED == A3
 #define LED_NAME "A3"
 #undef LED
 #define LED_PORT    VPORTA
-#define LED	    PORT3
+#define LED	    (1<<PORT3)
 #elif LED == A4
 #define LED_NAME "A4"
 #undef LED
 #define LED_PORT    VPORTA
-#define LED	    PORT4
+#define LED	    (1<<PORT4)
 #elif LED == A5
 #define LED_NAME "A5"
 #undef LED
 #define LED_PORT    VPORTA
-#define LED	    PORT5
+#define LED	    (1<<PORT5)
 #elif LED == A6
 #define LED_NAME "A6"
 #undef LED
 #define LED_PORT    VPORTA
-#define LED	    PORT6
+#define LED	    (1<<PORT6)
 #elif LED == A7
 #define LED_NAME "A7"
 #undef LED
 #define LED_PORT    VPORTA
-#define LED	    PORT7
+#define LED	    (1<<PORT7)
 
 #else
 // Stop compilation right away, so we don't get more errors.
@@ -667,7 +667,7 @@
 /*
  * Handle devices with up to 4 uarts.  Rather inelegantly.
  */
-#define MYUART_ALTPMUX 1
+#define USART_ALTPMUX 1
 
 #if defined(__AVR_ATmega4809__)
 # if (UARTTX == A0)
@@ -676,14 +676,14 @@
 #  endif
 #  define MYUART USART0
 #  define MYUART_TXPORT VPORTA
-#  define MYUART_TXPIN PORT0
+#  define MYUART_TXPIN (1<<PORT0)
 # elif (UARTTX == A4)
 #  ifndef USART0
 #   error Pin on USART0, but no USART0 exists
 #  endif
 #  define MYUART USART0
 #  define MYUART_TXPORT VPORTA
-#  define MYUART_TXPIN PORT4
+#  define MYUART_TXPIN (1<<PORT4)
 #  define MYUART_PMUX (USART_ALTPMUX<<PORTMUX_USART0_gp)
 # elif (UARTTX == B0)
 #  ifndef USART3
@@ -691,14 +691,14 @@
 #  endif
 #  define MYUART USART3
 #  define MYUART_TXPORT VPORTB
-#  define MYUART_TXPIN PORT0
+#  define MYUART_TXPIN (1<<PORT0)
 # elif (UARTTX == B4)
 #  ifndef USART3
 #   error Pin on USART3, but no USART3 exists
 #  endif
 #  define MYUART USART3
 #  define MYUART_TXPORT VPORTB
-#  define MYUART_TXPIN PORT4
+#  define MYUART_TXPIN (1<<PORT4)
 #  define MYUART_PMUX (USART_ALTPMUX<<PORTMUX_USART3_gp)
 # elif (UARTTX == C0)
 #  ifndef USART1
@@ -706,14 +706,14 @@
 #  endif
 #  define MYUART USART1
 #  define MYUART_TXPORT VPORTC
-#  define MYUART_TXPIN PORT0
+#  define MYUART_TXPIN (1<<PORT0)
 # elif (UARTTX == C4)
 #  ifndef USART1
 #   error Pin on USART1, but no USART1 exists
 #  endif
 #  define MYUART USART1
 #  define MYUART_TXPORT VPORTC
-#  define MYUART_TXPIN PORT4
+#  define MYUART_TXPIN (1<<PORT4)
 #  define MYUART_PMUX (USART_ALTPMUX<<PORTMUX_USART1_gp)
 # elif (UARTTX == F0)
 #  ifndef USART2
@@ -721,14 +721,14 @@
 #  endif
 #  define MYUART USART2
 #  define MYUART_TXPORT VPORTF
-#  define MYUART_TXPIN PORT0
+#  define MYUART_TXPIN (1<<PORT0)
 # elif (UARTTX == F4)
 #  ifndef USART2
 #   error Pin on USART2, but no USART2 exists
 #  endif
 #  define MYUART USART2
 #  define MYUART_TXPORT VPORTF
-#  define MYUART_TXPIN PORT4
+#  define MYUART_TXPIN (1<<PORT4)
 #  define MYUART_PMUX (USART_ALTPMUX<<PORTMUX_USART2_gp)
 # endif
 #endif // ATmega4809