Re: [Amforth] Building amForth with Microchip Studio 7

[Helge K. <Hel...@gm...>]

On 09.09.2021 09:37, Tristan Williams wrote:
> Hi Helge,
>
> A mystery, but given that, as far as I know, every (modern) build
> eventually uses avrasm2.exe to create the hex files, one that should
> be solvable.
I absolutely agree. And the Studio 7 comes with avrasm2. There is a
version update from 2.1.52 as you can find in
appl\atmega2561\atmega256.lst to the current version 2.2.8. But this is
not important.

> Given that you have an UNO build working, I can only
> think that your atmega2560 build is not finding all the needed files
> (or finding some it shouldn't) or that the build target is not
> actually an atmega2560.
The target is an atmega2560. The device signature is 0x1e9801, and C
programs run fine.

> I use a Makefile based build (on macos) that is based on the one that
> is part of the distribution. I can send you an archive with the
> Makefile, list file, etc. for you to check over. I don't have access
> to a Windows machine or I would try to replicate what you are doing.
It was not a question of the build environment (make/Studio) or the OS.

The main difference between the ATmega328P and the ATmega2560 is the  is
that the file appl_8k.inc is included, if the flash size is > 8000. The
asmforth.asm can't be used in that case as it is described in
http://amforth.sourceforge.net/UG/windows.html

Instead of "amforth.asm" the file "asmforth-low.asm" must be included.
This can also be found at appl\atmega2561\atmega256.asm. But this
example is not for Arduino ATMEGA256. It uses a different USART for the
terminal.

Here is my working example:

; First is to include macros and default settings from the amforth
; directory.
	.include "preamble.inc"
; amforth needs two essential parameters
; CPU clock in hertz, 1MHz is factory default
	.equ F_CPU = 16000000
; and the actual USART port.
	.include "drivers/usart_0.asm"
; Include the whole source tree.
	.include "amforth-low.asm"

And here are the avrdude parameter to flash the device
-c usbasp -p m2560 -V -u -U flash:w:my.hex -U eeprom:w:my.eep \
	-U efuse:w:0xFD:m -U hfuse:w:0xDF:m -U lfuse:w:0xFF:m

I am happy that I can now start Forth on my ATMEGA2560 Arduino.

Best regards,
Helge