booting

rpi/default.nix

@@ -1,6 +1,8 @@
 { core-overlay, libcamera-overlay }:
 { lib, pkgs, config, ... }:
 
+let cfg = config.raspberry-pi-nix;
+in
 {
   imports = [ ../sd-image ./config.nix ./i2c.nix ];
 
@@ -18,18 +20,41 @@
           type = types.bool;
         };
       };
+      uboot = {
+        enable = mkOption {
+          default = true;
+          type = types.bool;
+        };
+      };
     };
   };
 
   config = {
+    boot.kernelParams =
+      if cfg.uboot.enable then [ ]
+      else [
+        "root=PARTUUID=2178694e-02" # todo: use option
+        "rootfstype=ext4"
+        "fsck.repair=yes"
+        "rootwait"
+        "init=/sbin/init"
+      ];
     systemd.services = {
       "raspberry-pi-firmware-migrate" =
-        lib.mkIf config.raspberry-pi-nix.firmware-migration-service.enable {
+        {
           description = "update the firmware partition";
-          wantedBy = [ "multi-user.target" ];
+          wantedBy = if cfg.firmware-migration-service.enable then [ "multi-user.target" ] else [ ];
           serviceConfig =
-            let firmware-path = "/boot/firmware";
+            let
-            in {
+              firmware-path = "/boot/firmware";
+              kernel-params = pkgs.writeTextFile {
+                name = "cmdline.txt";
+                text = ''
+                  ${lib.strings.concatStringsSep " " config.boot.kernelParams}
+                '';
+              };
+            in
+            {
               Type = "oneshot";
               MountImages =
                 "/dev/disk/by-label/${config.sdImage.firmwarePartitionName}:${firmware-path}";
@@ -41,6 +66,8 @@
                 TARGET_OVERLAYS_DIR="$TARGET_FIRMWARE_DIR/overlays"
                 TMPFILE="$TARGET_FIRMWARE_DIR/tmp"
                 UBOOT="${pkgs.uboot_rpi_arm64}/u-boot.bin"
+                KERNEL="${pkgs.rpi-kernels.latest.kernel}/Image"
+                SHOULD_UBOOT=${if cfg.uboot.enable then "1" else "0"}
                 SRC_FIRMWARE_DIR="${pkgs.raspberrypifw}/share/raspberrypi/boot"
                 STARTFILES=("$SRC_FIRMWARE_DIR"/start*.elf)
                 DTBS=("$SRC_FIRMWARE_DIR"/*.dtb)
@@ -61,6 +88,28 @@
                   rm "$STATE_DIRECTORY/uboot-migration-in-progress"
                 }
 
+                migrate_kernel() {
+                  echo "migrating kernel"
+                  touch "$STATE_DIRECTORY/kernel-migration-in-progress"
+                  cp "$KERNEL" "$TMPFILE"
+                  mv -T "$TMPFILE" "$TARGET_FIRMWARE_DIR/kernel.img"
+                  echo "${
+                    builtins.toString pkgs.rpi-kernels.latest.kernel
+                  }" > "$STATE_DIRECTORY/kernel-version"
+                  rm "$STATE_DIRECTORY/kernel-migration-in-progress"
+                }
+
+                migrate_cmdline() {
+                  echo "migrating cmdline"
+                  touch "$STATE_DIRECTORY/cmdline-migration-in-progress"
+                  cp "${kernel-params}" "$TMPFILE"
+                  mv -T "$TMPFILE" "$TARGET_FIRMWARE_DIR/cmdline.txt"
+                  echo "${
+                    builtins.toString kernel-params
+                  }" > "$STATE_DIRECTORY/cmdline-version"
+                  rm "$STATE_DIRECTORY/cmdline-migration-in-progress"
+                }
+
                 migrate_config() {
                   echo "migrating config.txt"
                   touch "$STATE_DIRECTORY/config-migration-in-progress"
@@ -94,12 +143,24 @@
                   rm "$STATE_DIRECTORY/firmware-migration-in-progress"
                 }
 
-                if [[ -f "$STATE_DIRECTORY/uboot-migration-in-progress" || ! -f "$STATE_DIRECTORY/uboot-version" || $(< "$STATE_DIRECTORY/uboot-version") != ${
+                if [[ "$SHOULD_UBOOT" -eq 1 ]] && [[ -f "$STATE_DIRECTORY/uboot-migration-in-progress" || ! -f "$STATE_DIRECTORY/uboot-version" || $(< "$STATE_DIRECTORY/uboot-version") != ${
                   builtins.toString pkgs.uboot_rpi_arm64
                 } ]]; then
                   migrate_uboot
                 fi
 
+                if [[ "$SHOULD_UBOOT" -ne 1 ]] && [[ ! -f "$STATE_DIRECTORY/kernel-version" || $(< "$STATE_DIRECTORY/kernel-version") != ${
+                  builtins.toString pkgs.rpi-kernels.latest.kernel
+                } ]]; then
+                  migrate_kernel
+                fi
+
+                if [[ "$SHOULD_UBOOT" -ne 1 ]] && [[ ! -f "$STATE_DIRECTORY/cmdline-version" || $(< "$STATE_DIRECTORY/cmdline-version") != ${
+                  builtins.toString kernel-params
+                } ]]; then
+                  migrate_cmdline
+                fi
+
                 if [[ -f "$STATE_DIRECTORY/config-migration-in-progress" || ! -f "$STATE_DIRECTORY/config-version" || $(< "$STATE_DIRECTORY/config-version") != ${
                   builtins.toString config.hardware.raspberry-pi.config-output
                 } ]]; then
@@ -194,8 +255,9 @@
 
       loader = {
         grub.enable = lib.mkDefault false;
+        initScript.enable = !cfg.uboot.enable;
         generic-extlinux-compatible = {
-          enable = lib.mkDefault true;
+          enable = lib.mkDefault cfg.uboot.enable;
           # We want to use the device tree provided by firmware, so don't
           # add FDTDIR to the extlinux conf file.
           useGenerationDeviceTree = false;

sd-image/default.nix

@@ -5,23 +5,51 @@
 
   config = {
     boot.loader.grub.enable = false;
-    boot.loader.generic-extlinux-compatible.enable = true;
 
     boot.consoleLogLevel = lib.mkDefault 7;
 
     # https://github.com/raspberrypi/firmware/issues/1539#issuecomment-784498108
     boot.kernelParams = [ "console=serial0,115200n8" "console=tty1" ];
 
-    sdImage = {
+    sdImage =
-      populateFirmwareCommands = ''
+      let
-        cp ${pkgs.uboot_rpi_arm64}/u-boot.bin firmware/u-boot-rpi-arm64.bin
+        kernel-params = pkgs.writeTextFile {
-        cp -r ${pkgs.raspberrypifw}/share/raspberrypi/boot/{start*.elf,*.dtb,bootcode.bin,fixup*.dat,overlays} firmware
+          name = "cmdline.txt";
-        cp ${config.hardware.raspberry-pi.config-output} firmware/config.txt
+          text = ''
-      '';
+            ${lib.strings.concatStringsSep " " config.boot.kernelParams}
-      populateRootCommands = ''
+          '';
-        mkdir -p ./files/boot
+        };
-        ${config.boot.loader.generic-extlinux-compatible.populateCmd} -c ${config.system.build.toplevel} -d ./files/boot
+        populate-kernel =
-      '';
+          if config.raspberry-pi-nix.uboot.enable
-    };
+          then ''
+            cp ${pkgs.uboot_rpi_arm64}/u-boot.bin firmware/u-boot-rpi-arm64.bin
+          ''
+          else ''
+            cp "${pkgs.rpi-kernels.latest.kernel}/Image" firmware/kernel.img
+            cp "${kernel-params}" firmware/cmdline.txt
+          '';
+      in
+      {
+        populateFirmwareCommands = ''
+          ${populate-kernel}
+          cp -r ${pkgs.raspberrypifw}/share/raspberrypi/boot/{start*.elf,*.dtb,bootcode.bin,fixup*.dat,overlays} firmware
+          cp ${config.hardware.raspberry-pi.config-output} firmware/config.txt
+        '';
+        populateRootCommands =
+          if config.raspberry-pi-nix.uboot.enable
+          then ''
+            mkdir -p ./files/boot
+            ${config.boot.loader.generic-extlinux-compatible.populateCmd} -c ${config.system.build.toplevel} -d ./files/boot
+          ''
+          else ''
+            mkdir -p ./files/sbin
+            content="$(
+              echo "#!${config.system.build.toplevel.pkgs.bashInteractive}/bin/bash"
+              echo "exec ${config.system.build.toplevel}/init"
+            )"
+            echo "$content" > ./files/sbin/init
+            chmod 744 ./files/sbin/init
+          '';
+      };
   };
 }