Rename kboot-conf to petitboot and simplify a few things

hardkernel/odroid-m1/default.nix

@@ -1,31 +1,36 @@
-# Based on kboot-conf by original authors povik and sstent.
-# I'm just porting things over. the original work can be viewed at:
-# https://github.com/sstent/nixos-on-odroid-m1
-# https://github.com/povik/nixos-on-odroid-n2
 { config, pkgs, lib, ... }:
 
 {
   imports = [
-    ./kboot-conf
+    ./petitboot
   ];
 
-  #boot.loader.grub.enable = false;
-  boot.loader.kboot-conf.enable = true;
+  boot.loader.petitboot.enable = lib.mkForce true;
+
+  # Fails to rebuild unless grub is explicitly disabled
+  boot.loader.grub.enable = lib.mkForce false;
+
+  # TODO: Can this be removed? Presumably anything built with 25.11 / unstable
+  #       or later will be on a kernel >6.6
   # Use kernel >6.6 The devicetree is missing from kernel versions older than this.
   boot.kernelPackages = lib.mkIf (lib.versionOlder pkgs.linux.version "6.6") (lib.mkDefault pkgs.linuxPackages_latest);
+
+  # TODO: Debug why removing this breaks booting from petitboot
   boot.supportedFilesystems = lib.mkForce ["btrfs" "cifs" "f2fs" "jfs" "ntfs" "reiserfs" "vfat" "xfs"];
-  # I'm not completely sure if some of these could be omitted,
-  # but want to make sure disk access works
+
+  # TODO: Some of these could potentially be omitted, check which ones are
+  #       actually necessary for disk access to function
   boot.initrd.availableKernelModules = [
+    # Only nvme emitted when using nixos-generate-config on my odroid-m1
     "nvme"
-    "nvme-core"
-    "phy-rockchip-naneng-combphy"
-    "phy-rockchip-snps-pcie3"
+    # "nvme-core"
+    # "phy-rockchip-naneng-combphy"
+    # "phy-rockchip-snps-pcie3"
   ];
 
-  # Petitboot uses this port and baud rate on the boards serial port,
-  # it's probably good to keep the options same for the running
-  # kernel for serial console access to work well
+  # Petitboot uses this port and baud rate on the board's serial port. It's
+  # probably good to keep the options same for the running kernel for serial
+  # console access to work well.
   boot.kernelParams = ["console=ttyS2,1500000"];
   hardware.deviceTree.name = "rockchip/rk3568-odroid-m1.dtb";
 }

hardkernel/odroid-m1/kboot-conf/default.nix

@@ -1,73 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let
-  cfg = config.boot.loader.kboot-conf;
-
-  # The builder used to write during system activation
-  builder = pkgs.replaceVarsWith {
-    src = ./generate-kboot-conf.sh;
-    replacements = {
-      bash = pkgs.bash;
-      path = lib.makeBinPath [
-        pkgs.coreutils
-        pkgs.gnused
-        pkgs.gnugrep
-      ];
-    };
-    name = "system-activation-generate-kboot-conf";
-    isExecutable = true;
-  };
-  # The builder exposed in populateCmd, which runs when building the sdImage
-  populateBuilder = pkgs.buildPackages.replaceVarsWith {
-    src = ./generate-kboot-conf.sh;
-    replacements = {
-      bash = pkgs.buildPackages.bash;
-      path = lib.makeBinPath [
-        pkgs.buildPackages.coreutils
-        pkgs.buildPackages.gnused
-        pkgs.buildPackages.gnugrep
-      ];
-    };
-    name = "build-image-generate-kboot-conf";
-    isExecutable = true;
-  };
-in
-{
-  options = {
-    boot.loader.kboot-conf = {
-      enable = lib.mkOption {
-        default = false;
-        type = lib.types.bool;
-        description = ''
-          Whether to create petitboot-compatible /kboot.conf
-        '';
-      };
-      configurationLimit = lib.mkOption {
-        default = 10;
-        example = 5;
-        type = lib.types.int;
-        description = ''
-          Maximum number of configurations in the generated kboot.conf.
-        '';
-      };
-      populateCmd = lib.mkOption {
-        type = lib.types.str;
-        readOnly = true;
-        description = ''
-          Contains the builder command used to populate an image,
-          honoring all options except the <literal>-c &lt;path-to-default-configuration&gt;</literal>
-          argument.
-          Useful to have for sdImage.populateRootCommands
-        '';
-      };
-    };
-  };
-  config = let
-    args = "-g ${toString cfg.configurationLimit} -n ${config.hardware.deviceTree.name}";
-  in
-    lib.mkIf cfg.enable {
-      system.build.installBootLoader = lib.mkForce "${builder} ${args} -c";
-      system.boot.loader.id = "kboot-conf";
-      boot.loader.kboot-conf.populateCmd = "${populateBuilder} ${args}";
-    };
-}

hardkernel/odroid-m1/petitboot/default.nix

@@ -0,0 +1,75 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  cfg = config.boot.loader.petitboot;
+  args = "-g ${toString cfg.configurationLimit} -n ${config.hardware.deviceTree.name}";
+
+  # The installer used when running nixos-rebuild switch or similar
+  installer = pkgs.replaceVarsWith {
+    src = ./install-petitboot.sh;
+    replacements = {
+      bash = pkgs.bash;
+      path = lib.makeBinPath [
+        pkgs.coreutils
+        pkgs.gnused
+        pkgs.gnugrep
+      ];
+    };
+    name = "install-petitboot";
+    isExecutable = true;
+  };
+  # The installer used to write to SD card images
+  sdImageInstaller = pkgs.buildPackages.replaceVarsWith {
+    src = ./install-petitboot.sh;
+    replacements = {
+      bash = pkgs.buildPackages.bash;
+      path = lib.makeBinPath [
+        pkgs.buildPackages.coreutils
+        pkgs.buildPackages.gnused
+        pkgs.buildPackages.gnugrep
+      ];
+    };
+    name = "install-petitboot-sd-image";
+    isExecutable = true;
+  };
+in
+{
+  options = {
+    boot.loader.petitboot = {
+      enable = lib.mkOption {
+        default = false;
+        type = lib.types.bool;
+        description = ''
+          Whether to enable the Petitboot bootloader.
+        '';
+      };
+
+      configurationLimit = lib.mkOption {
+        default = 10;
+        example = 5;
+        type = lib.types.int;
+        description = ''
+          Maximum number of configurations to display when booting.
+        '';
+      };
+    };
+  };
+
+  config = lib.mkMerge[
+    (lib.mkIf config.boot.loader.petitboot.enable {
+      system.build.installBootLoader = lib.mkForce "${installer} ${args} -c";
+      system.boot.loader.id = "petitboot";
+    })
+
+    (lib.mkIf config.boot.loader.petitboot.enable && options ? sdImage {
+      sdImage.populateRootCommands = lib.mkForce ''
+        ${sdImageInstaller} ${args} -c ${config.system.build.toplevel} -d ./files/kboot.conf
+      ''
+    })
+  ];
+}

hardkernel/odroid-m1/petitboot/install-petitboot.sh

@@ -57,7 +57,7 @@ addEntry() {
     echo "'"
 }
 
-echo "# Auto-generated by generate-kboot-conf.sh, do not edit" > $tmp
+echo "# Auto-generated by install-petitboot.sh, do not edit or remove" > $tmp
 addEntry $default default >> $tmp
 
 if [ "$numGenerations" -gt 0 ]; then