Add HAL for Raspberry Pi Pico VGABOARD

[CHiPs44]

Hello,

It would be great to have an HAL for Raspberry Pi Pico VGABOARD as documented in https://github.com/raspberrypi/pico-extras/tree/master/src/common/pico_scanvideo/ & al. and implemented by Pimoroni with the VGA Demo Board.

Regards,

[tuupola]

Yeah this is an interesting board. I do not have it myself though. If anyone is planning to implement this the only mandatory thing to implement is the hagl_hal_put_pixel() function. Everything else is just a bonus which can be used to make the main things faster.

[CHiPs44]

A naive implementation (WIP) is available at https://github.com/CHiPs44/hagl_pico_vgaboard

[CHiPs44]

Implementation is less naive now, but still WIP.

[tuupola]

Looks great! I still haven't bought myself a vgaboard...