Remora - Rpi Software Stepping Using External Microcontroller via SPI

In the work I have been doing on the NVEM Ethernet version of Remora I have now been able to store and retrieve the config.txt file contents to and from the Flash memory of the STM32. I've been working on this as there is no SD card on the NVEM and we can send the config over Ethernet to the board.

Is this a feature, the Flash storage that is, that people would use on 3D printer controller boards. This would allow the removal of the SD card. The only time the SD card would need to be inserted would be for firmware or config updates.

Either this method or else a protocol to receive the configuration at startup would be quite useful to extend remora to boards that do not have an SD slot.  Although in many cases I think it could be enough to simply make it easy to custom-compile a fixed feature build where the steppers, inputs and outputs are hard-coded.

I love the accessibility of sd card for firmware/config, but sd card has become my main hurdle. I dont like having to use 2-8gb sd card to store less than 1mb , and I am facing compatibility issues with sd cards between sdio/spi read types. If you have a solution to make sd cards entirely optional, and able to load configs via spi or what ever you have planned, this would open up the number of available boards to remora. I could add 3-5 new boards without needing additional hardware.

Thanks for the feedback. Looks like the ability to load the firmware over SPI / Ethernet would be a beneficial feature. I'll look into how a TFTP type handshake protocol could be used over SPI to send the config to the board. The Flash storage and retrieval is already working great.

Hi Scott i'm back. i finished fews project and i'm ready now to test new platform for Remora.
I saw your code for NVEM and i was very happy to see you using STMcubeide, it's the best ide for STM32.
i tested the binary for F103RC on a F103RE and it works very good.
I was trying to compile the code, for STM32F4 no errors or warnings as usual, but i have errors when trying to compile STM32F1 : 

i'm trying to compile the Remora-feature-ethernet branch

yeah I couldnt get it to compile when I tried either,

speaking of remora ethernet feature, we just hook up the w5500 to the 4 spi lines correct?

i'm not testing the ethernet feature, only the branch for spi. The STMF1 don't compile on both devellop branch and ethernet branch.
I want to create new boards targets to support F103VET and F103ZET but without compilation that's gonna be difficult