arm: mediatek: add support for MediaTek MT7988 SoC
This patch adds basic support for MediaTek MT7988 SoC.
This includes files that will initialize the SoC after boot and
its device tree.
diff --git a/arch/arm/mach-mediatek/mt7988/lowlevel_init.S b/arch/arm/mach-mediatek/mt7988/lowlevel_init.S
new file mode 100644
index 0000000..2ae3cc4
--- /dev/null
+++ b/arch/arm/mach-mediatek/mt7988/lowlevel_init.S
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 MediaTek Inc.
+ * Author: Sam Shih <sam.shih@mediatek.com>
+ */
+
+/*
+ * Switch from AArch64 EL2 to AArch32 EL2
+ * @param inputs:
+ * x0: argument, zero
+ * x1: machine nr
+ * x2: fdt address
+ * x3: input argument
+ * x4: kernel entry point
+ * @param outputs for secure firmware:
+ * x0: function id
+ * x1: kernel entry point
+ * x2: machine nr
+ * x3: fdt address
+*/
+
+.global armv8_el2_to_aarch32
+armv8_el2_to_aarch32:
+ mov x3, x2
+ mov x2, x1
+ mov x1, x4
+ mov x4, #0
+ ldr x0, =0x82000200
+ SMC #0
+ ret