How small could this firmware go?

Question

How small could this firmware go?

mithro opened this issue 6 years ago · 5 comments

I was wondering how small you could make a UF2 compatible firmware? Could you fit it into a M0+ class device? Could you combined it with something like @xobs' https://github.com/xobs/grainuum stack?

mithro commented 6 years ago

Or UF2?

Answer 1 · 2018-10-15T00:31:39.000Z

I have an example of Grainuum running on an M0+ bootloader at https://github.com/xobs/joyboot however it's using HID and not U2F. If I were to redo joyboot (to actually produce the boards) I would use U2F now.

Answer 2 · 2018-10-15T01:08:05.000Z

By that I assume you mean DFU rather than U2F?

Answer 3 · 2018-10-15T01:18:06.000Z

...yes, sorry. I hadn't heard of UF2 before, but I suppose the joyboot firmware could be easily adapted to UF2.

Answer 4 · 2019-04-25T19:45:39.000Z

sorry for late reply, here's one for STM32F1 (which is M3, but small) https://github.com/mmoskal/uf2-stm32f103; here's one for SAMD21 (which is M0+) https://github.com/Microsoft/uf2-samdx1

I even had it running on the atmega usb interface chip of uno.

For full list see here https://github.com/Microsoft/uf2#bootloaders