Recent Posts
View allAdding HDMI support to the SG2000
With the working SD image preserved, trace an irreplaceable board's display path through boot files, schematics, and Linux drivers. One reversible device-tree change enables the control bus and makes the HDMI bridge's identity registers answer.
Sharing a host's Nix store with a builder VM
A build VM can read its host's Nix store through a read-only share. The host's files stay immutable; the VM's view of them doesn't. Its garbage collector can hide shared files behind overlay whiteouts unless the VM is told, on every start, that those files are still needed.
Built and running
BillTracker · legislative tracking for advocacy orgs · a few thousand users · the same droplet and script serve this site
live · billtracker.site· How it's deployed · Elixir/Phoenix LiveView · PostgreSQL · Oban · NixOS
Build and deploy infrastructure · A Nix remote builder isolated in a microVM on a shared host, the host's Nix store shared into it, and one-script deploys to a single droplet.
finished · 3 posts →
Linux drivers and bring-up · A DSI host driver for the SG2000 on a mainline kernel, debugged by diffing registers against the vendor image.
in progress · 1 post →· BadgeOS #7
Kernel security · Kernel exploits rebuilt as Nix derivations, and the page-cache bug the build sandbox can't contain.
finished · 2 posts →