[Amforth] Bootloader

[Enoch <ix...@ho...>]

Hello Matthias,

I hope that you agree with me that AmForth should allow placing user
code into the NRWW area. In my case, I need to put BOOFA there, an
avrdude compatible 512W bootloader (https://github.com/wexi/boofa), or
otherwise further development of my multi-board CANbus system would
become a living hell.

As your faithful shadow I have to introduce just the minimally invasive
changes to your code. Thus, to deal with your new flash allocation
challenge this is the *ugly* (but simplest) solution that I found:

dict_core_mcu.inc
~~~~~~~~~~~~~~~~~
.if AMFORTH_RO_SEG > NRWW_START_ADDR
   .include "dict/core_4k.inc"
.else
   .include "dict/core_8k.inc"
.endif

dict_mcu.inc
~~~~~~~~~~~~
.if AMFORTH_RO_SEG > NRWW_START_ADDR
   .include "dict/appl_4k.inc"
.else
   .include "dict/appl_8k.inc"
.endif

While I concur with your design objective to pack as much as possible
code into the core I have to disagree with your static (mcu dependent)
allocation method. Instead, a simple macro call ahead of each included
asm could have achieved just the same, a macro that checks the "pc"
distance to the "FLASHEND"... Enough said :-)

Thanks, Enoch.