diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 9b155e505..20cb04a6b 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -163,6 +163,7 @@ kernel = {
arm_coreboot = bus/fdt.c;
arm_coreboot = term/ps2.c;
arm_coreboot = term/arm/pl050.c;
+ arm_coreboot = bus/spi/rk3288_spi.c;
arm_coreboot = commands/keylayouts.c;
arm_coreboot = kern/arm/coreboot/dma.c;
diff --git a/grub-core/bus/spi/rk3288_spi.c b/grub-core/bus/spi/rk3288_spi.c
new file mode 100644
index 000000000..aacb79ffe
--- /dev/null
+++ b/grub-core/bus/spi/rk3288_spi.c
@@ -0,0 +1,103 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ *
+ * Copyright (C) 2012 Google Inc.
+ * Copyright (C) 2016 Free Software Foundation, Inc.
+ *
+ * This is based on depthcharge code.
+ *
+ * GRUB 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, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see .
+ */
+
+#include
+#include
+#include
+#include
+#include
+
+static grub_err_t
+spi_send (const struct grub_fdtbus_dev *dev, const void *data, grub_size_t sz)
+{
+ const grub_uint8_t *ptr = data, *end = ptr + sz;
+ volatile grub_uint32_t *spi = grub_fdtbus_map_reg (dev, 0, 0);
+ spi[2] = 0;
+ spi[1] = sz - 1;
+ spi[0] = ((1 << 18) | spi[0]) & ~(1 << 19);
+ spi[2] = 1;
+ while (ptr < end)
+ {
+ while (spi[9] & 2);
+ spi[256] = *ptr++;
+ }
+ while (spi[9] & 1);
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+spi_receive (const struct grub_fdtbus_dev *dev, void *data, grub_size_t sz)
+{
+ grub_uint8_t *ptr = data, *end = ptr + sz;
+ volatile grub_uint32_t *spi = grub_fdtbus_map_reg (dev, 0, 0);
+ spi[2] = 0;
+ spi[1] = sz - 1;
+ spi[0] = ((1 << 19) | spi[0]) & ~(1 << 18);
+ spi[2] = 1;
+ while (ptr < end)
+ {
+ while (spi[9] & 8);
+ *ptr++ = spi[512];
+ }
+ while (spi[9] & 1);
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+spi_start (const struct grub_fdtbus_dev *dev)
+{
+ volatile grub_uint32_t *spi = grub_fdtbus_map_reg (dev, 0, 0);
+ spi[3] = 1;
+ return GRUB_ERR_NONE;
+}
+
+static void
+spi_stop (const struct grub_fdtbus_dev *dev)
+{
+ volatile grub_uint32_t *spi = grub_fdtbus_map_reg (dev, 0, 0);
+ spi[3] = 0;
+}
+
+static grub_err_t
+spi_attach(const struct grub_fdtbus_dev *dev)
+{
+ if (!grub_fdtbus_is_mapping_valid (grub_fdtbus_map_reg (dev, 0, 0)))
+ return GRUB_ERR_IO;
+
+ return GRUB_ERR_NONE;
+}
+
+static struct grub_fdtbus_driver spi =
+{
+ .compatible = "rockchip,rk3288-spi",
+ .attach = spi_attach,
+ .send = spi_send,
+ .receive = spi_receive,
+ .start = spi_start,
+ .stop = spi_stop,
+};
+
+void
+grub_rk3288_spi_init (void)
+{
+ grub_fdtbus_register (&spi);
+}
diff --git a/grub-core/kern/arm/coreboot/init.c b/grub-core/kern/arm/coreboot/init.c
index a06ccb72f..0126ff638 100644
--- a/grub-core/kern/arm/coreboot/init.c
+++ b/grub-core/kern/arm/coreboot/init.c
@@ -132,6 +132,8 @@ grub_machine_init (void)
grub_fatal ("No DTB found");
grub_fdtbus_init (dtb, dtb_size);
+ grub_rk3288_spi_init ();
+
grub_machine_timer_init ();
grub_pl050_init ();
}
diff --git a/include/grub/arm/coreboot/kernel.h b/include/grub/arm/coreboot/kernel.h
index 09cd7fe32..269505342 100644
--- a/include/grub/arm/coreboot/kernel.h
+++ b/include/grub/arm/coreboot/kernel.h
@@ -34,8 +34,8 @@ struct grub_fdt_board
extern struct grub_fdt_board grub_fdt_boards[];
void grub_machine_timer_init (void);
void grub_pl050_init (void);
-void
-grub_cros_init (void);
+void grub_cros_init (void);
+void grub_rk3288_spi_init (void);
extern grub_addr_t EXPORT_VAR (start_of_ram);
#endif /* ! ASM_FILE */