chore: no double caching, compression now supported

README.md

@@ -27,10 +27,9 @@ complete example.
 {
   description = "raspberry-pi-nix example";
   nixConfig = {
-    extra-substituters = [ "https://raspberry-pi-nix.cachix.org" https://adminy.cachix.org ];
+    extra-substituters = [ "https://raspberry-pi-nix.cachix.org" ];
     extra-trusted-public-keys = [
       "raspberry-pi-nix.cachix.org-1:WmV2rdSangxW0rZjY/tBvBDSaNFQ3DyEQsVw8EvHn9o="
-      "adminy.cachix.org-1:xgrsLa9L9VCdTbY5dMDqtcl6qBFHA9U56SgEJosNbFc=""
     ];
   };
   inputs = {
@@ -293,3 +292,5 @@ is kept up to date by the overlay applied by this package, so you
 don't need configure this. However, if you want to use different
 firmware you can override that package to do so.
 
+## What's not working?
+- [ ] Pi 5 u-boot devices other than sd-cards (i.e. usb, nvme).

overlays/default.nix

@@ -70,11 +70,6 @@ let
   rpi-kernels = builtins.foldl' (b: a: b // rpi-kernel a) { };
 in
 {
-  # disable firmware compression so that brcm firmware can be found at
-  # the path expected by raspberry pi firmware/device tree
-  compressFirmwareXz = x: x;
-  compressFirmwareZstd = x: x;
-
   # provide generic rpi arm64 u-boot
   uboot_rpi_arm64 = prev.buildUBoot rec {
     defconfig = "rpi_arm64_defconfig";

rpi/config.nix

@@ -16,8 +16,7 @@ let
           (lib.filterAttrs (k: v: v.enable) x);
       render-dt-overlay = { overlay, args }:
         "dtoverlay=" + overlay + "\n"
-        + lib.strings.concatMapStringsSep "\n" render-dt-param args + "\n"
-        + "dtoverlay=";
+        + lib.strings.concatMapStringsSep "\n" render-dt-param args + "\n";
       render-base-dt-params = params:
         lib.strings.concatMapStringsSep "\n" render-dt-param
           (render-dt-kvs params);