** Generate a pure Mecrisp-Stellaris image for STM32F103 with serial i/o

#+BEGIN_EXAMPLE

cd $O/embello-1.6/explore/1608-forth/g6s
awk -f fpp.awk board36.hex > /tmp/forth-code.fs

cd $O/mecrisp-stellaris-2.4.1/mecrisp-stellaris-source/stm32f103-ra
make
cd $O/mecrisp-stellaris-2.4.1/thumbulator
./compile
./buildcore-stm ./thumbulator-stm32f103 \
                ../mecrisp-stellaris-source/stm32f103-ra/mecrisp-stellaris-stm32f103.bin \
                /tmp/forth-code.fs /tmp/image.bin

#+END_EXAMPLE

from :board.fs:
   - included proper pins36.fs
   - removed eraseflash from the beginning
   - added definition of cornerstone
   - removed calling of old init

#+BEGIN_EXAMPLE fpp.awk
BEGIN { FS=" " }
/^include / || /^require / {
        print "\\ " $0
        system("awk -f fpp.awk " $2)
        next }
{
        sub(/ \\ .*/, "")
        print }
#+END_EXAMPLE

#+BEGIN_EXAMPLE board36.fs
\ board definitions

\ eraseflash
\ cr
compiletoflash

( board start: ) here dup hex.

4 constant io-ports  \ A..D

include ../flib/mecrisp/calltrace.fs
include ../flib/mecrisp/cond.fs
include ../flib/mecrisp/hexdump.fs
include ../flib/stm32f1/io.fs
include ../flib/pkg/pins36.fs
include ../flib/stm32f1/hal.fs
include ../flib/stm32f1/spi.fs
include ../flib/stm32f1/i2c.fs
include ../flib/stm32f1/timer.fs
include ../flib/stm32f1/pwm.fs
include ../flib/stm32f1/adc.fs
include ../flib/stm32f1/rtc.fs

: cornerstone ( "name" -- )  \ define a flash memory cornerstone
  <builds begin here dup flash-pagesize 1- and while 0 h, repeat
  does>   begin dup  dup flash-pagesize 1- and while 2+   repeat  cr
  eraseflashfrom ;

: hello ( -- ) flash-kb . ." KB <g6s> " hwid hex.
  $10000 compiletoflash here -  flashvar-here compiletoram here -
  ." ram/flash: " . . ." free " ;

: init ( -- )  \ board initialisation
\ init  \ uses new uart init convention
  ['] ct-irq irq-fault !  \ show call trace in unhandled exceptions
  jtag-deinit  \ disable JTAG, we only need SWD
  72MHz
  1000 systick-hz
  hello ." ok." cr
;

cornerstone <<<board>>>
hello
words
#+END_EXAMPLE