DE10-Nano + NixOS Demo

Goal: build a bitstream and HPS image from source using Nix with no blobs or non-free non-mainline software (except for Quartus and mandatory Verilog IP)

Demo:

1. Set MSEL[4:0] to "00000" (i.e. all DIP switches UP)
2. nix build .#nixosConfigurations.de10-nano then zstdcat/dd result/sd-image/*.img.zst to an SD card
3. Plug in SD card, USB UART (115200 baud), and power, then run demo at prompt

Todo:

• non-maximal kernel config
• fix cross hacks
• refactor Nix derivation components to be more reusable
• more interesting demo
• some cool automatic way of assigning a MAC address
• more reasonable way of setting up bitstream under Linux
• bitstream compression and faster loading
• integrate Amaranth better incl. simulation