Setting Xboot with xmega256a3

Been playing with Xboot for use with the xmega256a3.  You can find the Xboot code here.  In the conf folder there are some example configurations.  I copied x64a3.conf.mk and created xmega256a3.conf.mk and modified the parameters as follows (only listing those that I changed):

MCU = atxmega256a3

F_CPU = 32000000

AVRDUDE_PROGRAMMER = avrispmkii

USE_AVR1008_EEPROM = yes

USE_INTERRUPTS = yes

USE_WATCHDOG = yes

ENTER_BLINK_COUNT     = 5

ENTER_BLINK_WAIT      = 600000

WATCHDOG_TIMEOUT      = WDT_PER_8KCLK_gc

LED_PORT_NAME         = C

LED_PIN               = 0

LED_INV               = 1

UART_BAUD_RATE        = 230400

UART_PORT_NAME        = C

UART_NUMBER           = 0

UART_RX_PUEN          = yes

Wanted a longer delay while in boot mode so I increased the blink count to 5 and increased the wait.  I also modified the XBOOT code to support a baud rate of 230400.  This I did by adding the following code to xboot.h:

#elif (F_CPU == 32000000L) && (UART_BAUD_RATE == 230400)

#define UART_BSEL_VALUE         123

#define UART_BSCALE_VALUE       -4

#define UART_CLK2X              0

When the code modifications are done, now just need to compile.  To do this move or copy xmega256a3.conf.mk up a directory and then do:

make clean

make xmega256a3.conf.mk

then to program:

make program

in protocol.h there are a bunch of single character commands that you can enter while the LED is blinking and get response.  Such as 'S' which will respond with "XBoot++".

If you want to use avrdude to program the application section of flash just do the following:

avrdude -p atxmega256a3 -P /dev/tty.usbserial-FTFXXXX -c avr109 -b 230400 -U flash:w:twig_xmega256a3.bin -e

with -P being the serial port, -b the baud rate and -e indicating to erase the chip (this is very important cause I have not been able to get it to work without this option).