diff --git a/src/mainboard/google/gru/board.h b/src/mainboard/google/gru/board.h
index c29aa51d50..afb3d21d31 100644
--- a/src/mainboard/google/gru/board.h
+++ b/src/mainboard/google/gru/board.h
@@ -1,17 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #ifndef __COREBOOT_SRC_MAINBOARD_GOOGLE_GRU_BOARD_H
 #define __COREBOOT_SRC_MAINBOARD_GOOGLE_GRU_BOARD_H
diff --git a/src/mainboard/google/gru/boardid.c b/src/mainboard/google/gru/boardid.c
index f3cda66604..3dd9e7c3bb 100644
--- a/src/mainboard/google/gru/boardid.c
+++ b/src/mainboard/google/gru/boardid.c
@@ -1,16 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <boardid.h>
 #include <console/console.h>
diff --git a/src/mainboard/google/gru/bootblock.c b/src/mainboard/google/gru/bootblock.c
index b09542e266..0110d339bd 100644
--- a/src/mainboard/google/gru/bootblock.c
+++ b/src/mainboard/google/gru/bootblock.c
@@ -1,17 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <device/mmio.h>
 #include <bootblock_common.h>
diff --git a/src/mainboard/google/gru/chromeos.c b/src/mainboard/google/gru/chromeos.c
index 3b2711e563..fc8e5f240e 100644
--- a/src/mainboard/google/gru/chromeos.c
+++ b/src/mainboard/google/gru/chromeos.c
@@ -1,17 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <bootmode.h>
 #include <boot/coreboot_tables.h>
diff --git a/src/mainboard/google/gru/mainboard.c b/src/mainboard/google/gru/mainboard.c
index 7d3c1a79d5..bc3fab2344 100644
--- a/src/mainboard/google/gru/mainboard.c
+++ b/src/mainboard/google/gru/mainboard.c
@@ -1,17 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <assert.h>
 #include <bl31.h>
diff --git a/src/mainboard/google/gru/memlayout.ld b/src/mainboard/google/gru/memlayout.ld
index 4b3e957339..eccd0c5fa1 100644
--- a/src/mainboard/google/gru/memlayout.ld
+++ b/src/mainboard/google/gru/memlayout.ld
@@ -1,15 +1,4 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
  #include <soc/memlayout.ld>
diff --git a/src/mainboard/google/gru/pwm_regulator.c b/src/mainboard/google/gru/pwm_regulator.c
index 7f42f890e8..148ced6268 100644
--- a/src/mainboard/google/gru/pwm_regulator.c
+++ b/src/mainboard/google/gru/pwm_regulator.c
@@ -1,16 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <device/mmio.h>
 #include <assert.h>
diff --git a/src/mainboard/google/gru/pwm_regulator.h b/src/mainboard/google/gru/pwm_regulator.h
index 6e5160b15b..3afb9d7eef 100644
--- a/src/mainboard/google/gru/pwm_regulator.h
+++ b/src/mainboard/google/gru/pwm_regulator.h
@@ -1,16 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #ifndef __COREBOOT_SRC_MAINBOARD_GOOGLE_GRU_PWM_REGULATOR_H
 #define __COREBOOT_SRC_MAINBOARD_GOOGLE_GRU_PWM_REGULATOR_H
diff --git a/src/mainboard/google/gru/reset.c b/src/mainboard/google/gru/reset.c
index c84e33af93..cd93609291 100644
--- a/src/mainboard/google/gru/reset.c
+++ b/src/mainboard/google/gru/reset.c
@@ -1,16 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <gpio.h>
 #include <reset.h>
diff --git a/src/mainboard/google/gru/romstage.c b/src/mainboard/google/gru/romstage.c
index ba0c7066e4..9505d3fb12 100644
--- a/src/mainboard/google/gru/romstage.c
+++ b/src/mainboard/google/gru/romstage.c
@@ -1,17 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <arch/mmu.h>
 #include <arch/stages.h>
diff --git a/src/mainboard/google/gru/sdram_configs.c b/src/mainboard/google/gru/sdram_configs.c
index 176e01c847..94011ff31c 100644
--- a/src/mainboard/google/gru/sdram_configs.c
+++ b/src/mainboard/google/gru/sdram_configs.c
@@ -1,16 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <boardid.h>
 #include <cbfs.h>
diff --git a/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-2GB-800.c b/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-2GB-800.c
index eb0854d59e..d777be6f5e 100644
--- a/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-2GB-800.c
+++ b/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-2GB-800.c
@@ -1,15 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <soc/sdram.h>
 
diff --git a/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-2GB-928.c b/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-2GB-928.c
index 552ebfc9b5..2795f9c9cf 100644
--- a/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-2GB-928.c
+++ b/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-2GB-928.c
@@ -1,15 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <soc/sdram.h>
 
diff --git a/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-4GB-800.c b/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-4GB-800.c
index a0b270c696..afa12e768f 100644
--- a/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-4GB-800.c
+++ b/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-4GB-800.c
@@ -1,15 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <soc/sdram.h>
 
diff --git a/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-4GB-928.c b/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-4GB-928.c
index f75e6b5bd5..2f77a1fe98 100644
--- a/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-4GB-928.c
+++ b/src/mainboard/google/gru/sdram_params/sdram-lpddr3-generic-4GB-928.c
@@ -1,15 +1,5 @@
-/*
- * This file is part of the coreboot project.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* This file is part of the coreboot project. */
 
 #include <soc/sdram.h>