orempel / twiboot Goto Github PK

Hi,
i ported twiboot to my Tiny84 target.
So far, it is working. I am able to download the code and start a small demo application via the I2C command.

Unfortunately, it is not starting without any I2C communication (timeout).
Any hint?

For debugging, i added some fast LED toggling just before jump_to_app();
The problem, is, that my app code is just not working, when it is started by timeout.

Additional, i think there is a concept error with the appvect_save variable.
I think, the appvect_save & rstvect_save are initialized with the wrong value in main.
When I check/compare without writing it, then i get a mismatch with the original code.

I think, it should be:
rstvect_save[0] = buf[APPVECT_PAGE_OFFSET];
rstvect_save[1] = buf[APPVECT_PAGE_OFFSET + 1];
appvect_save[0] = ?;
appvect_save[1] = ?;

I added a simple CRC16 checksum query. This is very useful doing a quick code compare without read the entire flash to the master.

Later, i like to add support for the AT Tiny841 too. This device has a different I2C slave implementation.

Shall i provide a pull request for this?

Maik

This is not an issue but just a remark.

You might like the "twoboot-proxy" which allows to use a leonardo to bridge between the Arduino IDE and a atmega328 based twiboot device:

https://github.com/harbaum/twiboot-proxy

Awesome work on twiboot! Any chance offering support for Tiny85? I changed the MCU in the Makefile and it seems some registers are Tiny85-specific..

Currently, my ATmega328p runs at 16MHz on an external clock (I set the fuse bits manually in a copy of the Makefile you provide). However, it would be nice to utilize a custom CPU frequency that doesn't require me manually editing the Makefile. This isn't something important, as it doesn't impact my project much (just that I have to be faster when stopping the abort boot timeout 😝). However, it would be nice to have.

I'd like to use this code in a product I am developing, but I cannot accept the GPL 2 license attached.

Are you open to changing the license? LGPL?