openwrt/package/boot/uboot-mediatek/patches/101-28-arm-mediatek-add-support-for-MediaTek-MT7988-SoC.patch
Daniel Golle 572ea68070 uboot-mediatek: add patches for MT7988 and builds for RFB
Import pending patches adding support for MT7988 and provide builds
for the reference board for all possible boot media.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
2023-07-29 15:07:11 +01:00

607 lines
16 KiB
Diff

From 884430dadcc2c5d0a2b248795001955a9fa5a1a9 Mon Sep 17 00:00:00 2001
From: Weijie Gao <weijie.gao@mediatek.com>
Date: Wed, 19 Jul 2023 17:17:49 +0800
Subject: [PATCH 28/29] 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.
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
---
arch/arm/dts/mt7988-u-boot.dtsi | 25 ++
arch/arm/dts/mt7988.dtsi | 391 ++++++++++++++++++
arch/arm/mach-mediatek/Kconfig | 13 +-
arch/arm/mach-mediatek/Makefile | 1 +
arch/arm/mach-mediatek/mt7988/Makefile | 4 +
arch/arm/mach-mediatek/mt7988/init.c | 63 +++
arch/arm/mach-mediatek/mt7988/lowlevel_init.S | 30 ++
7 files changed, 526 insertions(+), 1 deletion(-)
create mode 100644 arch/arm/dts/mt7988-u-boot.dtsi
create mode 100644 arch/arm/dts/mt7988.dtsi
create mode 100644 arch/arm/mach-mediatek/mt7988/Makefile
create mode 100644 arch/arm/mach-mediatek/mt7988/init.c
create mode 100644 arch/arm/mach-mediatek/mt7988/lowlevel_init.S
--- /dev/null
+++ b/arch/arm/dts/mt7988-u-boot.dtsi
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022 MediaTek Inc.
+ * Author: Sam Shih <sam.shih@mediatek.com>
+ */
+
+&system_clk {
+ bootph-all;
+};
+
+&spi_clk {
+ bootph-all;
+};
+
+&uart0 {
+ bootph-all;
+};
+
+&uart1 {
+ bootph-all;
+};
+
+&uart2 {
+ bootph-all;
+};
--- /dev/null
+++ b/arch/arm/dts/mt7988.dtsi
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022 MediaTek Inc.
+ * Author: Sam Shih <sam.shih@mediatek.com>
+ */
+
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+#include <dt-bindings/clock/mt7988-clk.h>
+#include <dt-bindings/reset/mt7988-reset.h>
+#include <dt-bindings/gpio/gpio.h>
+
+/ {
+ compatible = "mediatek,mt7988-rfb";
+ interrupt-parent = <&gic>;
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ cpu0: cpu@0 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a73";
+ reg = <0x0>;
+ mediatek,hwver = <&hwver>;
+ };
+
+ cpu1: cpu@1 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a73";
+ reg = <0x1>;
+ mediatek,hwver = <&hwver>;
+ };
+
+ cpu2: cpu@2 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a73";
+ reg = <0x2>;
+ mediatek,hwver = <&hwver>;
+ };
+
+ cpu3: cpu@3 {
+ device_type = "cpu";
+ compatible = "arm,cortex-a73";
+ reg = <0x3>;
+ mediatek,hwver = <&hwver>;
+ };
+ };
+
+ system_clk: dummy40m {
+ compatible = "fixed-clock";
+ clock-frequency = <40000000>;
+ #clock-cells = <0>;
+ };
+
+ spi_clk: dummy208m {
+ compatible = "fixed-clock";
+ clock-frequency = <208000000>;
+ #clock-cells = <0>;
+ };
+
+ hwver: hwver {
+ compatible = "mediatek,hwver", "syscon";
+ reg = <0 0x8000000 0 0x1000>;
+ };
+
+ timer {
+ compatible = "arm,armv8-timer";
+ interrupt-parent = <&gic>;
+ clock-frequency = <13000000>;
+ interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW>,
+ <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>;
+ };
+
+ watchdog: watchdog@1001c000 {
+ compatible = "mediatek,mt7622-wdt",
+ "mediatek,mt6589-wdt",
+ "syscon";
+ reg = <0 0x1001c000 0 0x1000>;
+ interrupts = <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
+ #reset-cells = <1>;
+ };
+
+ gic: interrupt-controller@c000000 {
+ compatible = "arm,gic-v3";
+ #interrupt-cells = <3>;
+ interrupt-parent = <&gic>;
+ interrupt-controller;
+ reg = <0 0x0c000000 0 0x40000>, /* GICD */
+ <0 0x0c080000 0 0x200000>; /* GICR */
+ interrupts = <GIC_PPI 9 IRQ_TYPE_LEVEL_HIGH>;
+ };
+
+ infracfg_ao_cgs: infracfg_ao_cgs@10001000 {
+ compatible = "mediatek,mt7988-infracfg_ao_cgs", "syscon";
+ reg = <0 0x10001000 0 0x1000>;
+ clock-parent = <&infracfg_ao>;
+ #clock-cells = <1>;
+ };
+
+ apmixedsys: apmixedsys@1001e000 {
+ compatible = "mediatek,mt7988-fixed-plls", "syscon";
+ reg = <0 0x1001e000 0 0x1000>;
+ #clock-cells = <1>;
+ };
+
+ topckgen: topckgen@1001b000 {
+ compatible = "mediatek,mt7988-topckgen", "syscon";
+ reg = <0 0x1001b000 0 0x1000>;
+ clock-parent = <&apmixedsys>;
+ #clock-cells = <1>;
+ };
+
+ pinctrl: pinctrl@1001f000 {
+ compatible = "mediatek,mt7988-pinctrl";
+ reg = <0 0x1001f000 0 0x1000>,
+ <0 0x11c10000 0 0x1000>,
+ <0 0x11d00000 0 0x1000>,
+ <0 0x11d20000 0 0x1000>,
+ <0 0x11e00000 0 0x1000>,
+ <0 0x11f00000 0 0x1000>,
+ <0 0x1000b000 0 0x1000>;
+ reg-names = "gpio_base", "iocfg_tr_base", "iocfg_br_base",
+ "iocfg_rb_base", "iocfg_lb_base", "iocfg_tl_base",
+ "eint";
+ gpio: gpio-controller {
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+ };
+
+ sgmiisys0: syscon@10060000 {
+ compatible = "mediatek,mt7988-sgmiisys_0", "syscon";
+ reg = <0 0x10060000 0 0x1000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ sgmiisys1: syscon@10070000 {
+ compatible = "mediatek,mt7988-sgmiisys_1", "syscon";
+ reg = <0 0x10070000 0 0x1000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ usxgmiisys0: syscon@10080000 {
+ compatible = "mediatek,mt7988-usxgmiisys_0", "syscon";
+ reg = <0 0x10080000 0 0x1000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ usxgmiisys1: syscon@10081000 {
+ compatible = "mediatek,mt7988-usxgmiisys_1", "syscon";
+ reg = <0 0x10081000 0 0x1000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ xfi_pextp0: syscon@11f20000 {
+ compatible = "mediatek,mt7988-xfi_pextp_0", "syscon";
+ reg = <0 0x11f20000 0 0x10000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ xfi_pextp1: syscon@11f30000 {
+ compatible = "mediatek,mt7988-xfi_pextp_1", "syscon";
+ reg = <0 0x11f30000 0 0x10000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ xfi_pll: syscon@11f40000 {
+ compatible = "mediatek,mt7988-xfi_pll", "syscon";
+ reg = <0 0x11f40000 0 0x1000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ topmisc: topmisc@11d10000 {
+ compatible = "mediatek,mt7988-topmisc", "syscon",
+ "mediatek,mt7988-power-controller";
+ reg = <0 0x11d10000 0 0x10000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ infracfg_ao: infracfg@10001000 {
+ compatible = "mediatek,mt7988-infracfg", "syscon";
+ reg = <0 0x10001000 0 0x1000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ };
+
+ uart0: serial@11000000 {
+ compatible = "mediatek,hsuart";
+ reg = <0 0x11000000 0 0x100>;
+ interrupts = <GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&infracfg_ao_cgs CK_INFRA_52M_UART0_CK>;
+ assigned-clocks = <&topckgen CK_TOP_UART_SEL>,
+ <&infracfg_ao CK_INFRA_MUX_UART0_SEL>;
+ assigned-clock-parents = <&topckgen CK_TOP_CB_CKSQ_40M>,
+ <&infracfg_ao CK_INFRA_UART_O0>;
+ status = "disabled";
+ };
+
+ uart1: serial@11000100 {
+ compatible = "mediatek,hsuart";
+ reg = <0 0x11000100 0 0x100>;
+ interrupts = <GIC_SPI 124 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&infracfg_ao_cgs CK_INFRA_52M_UART1_CK>;
+ assigned-clocks = <&topckgen CK_TOP_UART_SEL>,
+ <&infracfg_ao CK_INFRA_MUX_UART1_SEL>;
+ assigned-clock-parents = <&topckgen CK_TOP_CB_CKSQ_40M>,
+ <&infracfg_ao CK_INFRA_UART_O1>;
+ status = "disabled";
+ };
+
+ uart2: serial@11000200 {
+ compatible = "mediatek,hsuart";
+ reg = <0 0x11000200 0 0x100>;
+ interrupts = <GIC_SPI 125 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&infracfg_ao_cgs CK_INFRA_52M_UART2_CK>;
+ assigned-clocks = <&topckgen CK_TOP_UART_SEL>,
+ <&infracfg_ao CK_INFRA_MUX_UART2_SEL>;
+ assigned-clock-parents = <&topckgen CK_TOP_CB_CKSQ_40M>,
+ <&infracfg_ao CK_INFRA_UART_O2>;
+ status = "disabled";
+ };
+
+ i2c0: i2c@11003000 {
+ compatible = "mediatek,mt7988-i2c",
+ "mediatek,mt7981-i2c";
+ reg = <0 0x11003000 0 0x1000>,
+ <0 0x10217080 0 0x80>;
+ interrupts = <GIC_SPI 136 IRQ_TYPE_LEVEL_HIGH>;
+ clock-div = <1>;
+ clocks = <&infracfg_ao CK_INFRA_I2C_BCK>,
+ <&infracfg_ao CK_INFRA_66M_AP_DMA_BCK>;
+ clock-names = "main", "dma";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ status = "disabled";
+ };
+
+ i2c1: i2c@11004000 {
+ compatible = "mediatek,mt7988-i2c",
+ "mediatek,mt7981-i2c";
+ reg = <0 0x11004000 0 0x1000>,
+ <0 0x10217100 0 0x80>;
+ interrupts = <GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>;
+ clock-div = <1>;
+ clocks = <&infracfg_ao CK_INFRA_I2C_BCK>,
+ <&infracfg_ao CK_INFRA_66M_AP_DMA_BCK>;
+ clock-names = "main", "dma";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ status = "disabled";
+ };
+
+ i2c2: i2c@11005000 {
+ compatible = "mediatek,mt7988-i2c",
+ "mediatek,mt7981-i2c";
+ reg = <0 0x11005000 0 0x1000>,
+ <0 0x10217180 0 0x80>;
+ interrupts = <GIC_SPI 145 IRQ_TYPE_LEVEL_HIGH>;
+ clock-div = <1>;
+ clocks = <&infracfg_ao CK_INFRA_I2C_BCK>,
+ <&infracfg_ao CK_INFRA_66M_AP_DMA_BCK>;
+ clock-names = "main", "dma";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ status = "disabled";
+ };
+
+ pwm: pwm@10048000 {
+ compatible = "mediatek,mt7988-pwm";
+ reg = <0 0x10048000 0 0x1000>;
+ #pwm-cells = <2>;
+ clocks = <&infracfg_ao CK_INFRA_66M_PWM_BCK>,
+ <&infracfg_ao CK_INFRA_66M_PWM_HCK>,
+ <&infracfg_ao CK_INFRA_66M_PWM_CK1>,
+ <&infracfg_ao CK_INFRA_66M_PWM_CK2>,
+ <&infracfg_ao CK_INFRA_66M_PWM_CK3>,
+ <&infracfg_ao CK_INFRA_66M_PWM_CK4>,
+ <&infracfg_ao CK_INFRA_66M_PWM_CK5>,
+ <&infracfg_ao CK_INFRA_66M_PWM_CK6>,
+ <&infracfg_ao CK_INFRA_66M_PWM_CK7>,
+ <&infracfg_ao CK_INFRA_66M_PWM_CK8>;
+ clock-names = "top", "main", "pwm1", "pwm2", "pwm3",
+ "pwm4","pwm5","pwm6","pwm7","pwm8";
+ status = "disabled";
+ };
+
+ snand: snand@11001000 {
+ compatible = "mediatek,mt7988-snand",
+ "mediatek,mt7986-snand";
+ reg = <0 0x11001000 0 0x1000>,
+ <0 0x11002000 0 0x1000>;
+ reg-names = "nfi", "ecc";
+ interrupts = <GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&infracfg_ao CK_INFRA_SPINFI>,
+ <&infracfg_ao CK_INFRA_NFI>,
+ <&infracfg_ao CK_INFRA_66M_NFI_HCK>;
+ clock-names = "pad_clk", "nfi_clk", "nfi_hclk";
+ assigned-clocks = <&topckgen CK_TOP_SPINFI_SEL>,
+ <&topckgen CK_TOP_NFI1X_SEL>;
+ assigned-clock-parents = <&topckgen CK_TOP_CB_M_D8>,
+ <&topckgen CK_TOP_CB_M_D8>;
+ status = "disabled";
+ };
+
+ spi0: spi@1100a000 {
+ compatible = "mediatek,ipm-spi";
+ reg = <0 0x11007000 0 0x100>;
+ clocks = <&spi_clk>,
+ <&spi_clk>;
+ clock-names = "sel-clk", "spi-clk";
+ interrupts = <GIC_SPI 140 IRQ_TYPE_LEVEL_HIGH>;
+ status = "disabled";
+ };
+
+ spi1: spi@1100b000 {
+ compatible = "mediatek,ipm-spi";
+ reg = <0 0x11008000 0 0x100>;
+ interrupts = <GIC_SPI 141 IRQ_TYPE_LEVEL_HIGH>;
+ status = "disabled";
+ };
+
+ spi2: spi@11009000 {
+ compatible = "mediatek,ipm-spi";
+ reg = <0 0x11009000 0 0x100>;
+ clocks = <&spi_clk>,
+ <&spi_clk>;
+ clock-names = "sel-clk", "spi-clk";
+ interrupts = <GIC_SPI 142 IRQ_TYPE_LEVEL_HIGH>;
+ status = "disabled";
+ };
+
+ mmc0: mmc@11230000 {
+ compatible = "mediatek,mt7988-mmc",
+ "mediatek,mt7986-mmc";
+ reg = <0 0x11230000 0 0x1000>;
+ interrupts = <GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&infracfg_ao_cgs CK_INFRA_MSDC400>,
+ <&infracfg_ao_cgs CK_INFRA_MSDC2_HCK>,
+ <&infracfg_ao_cgs CK_INFRA_133M_MSDC_0_HCK>,
+ <&infracfg_ao_cgs CK_INFRA_66M_MSDC_0_HCK>;
+ clock-names = "source", "hclk", "source_cg", "axi_cg";
+ status = "disabled";
+ };
+
+ ethdma: syscon@15000000 {
+ compatible = "mediatek,mt7988-ethdma", "syscon";
+ reg = <0 0x15000000 0 0x20000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ #reset-cells = <1>;
+ };
+
+ ethwarp: syscon@15031000 {
+ compatible = "mediatek,mt7988-ethwarp", "syscon";
+ reg = <0 0x15031000 0 0x1000>;
+ clock-parent = <&topckgen>;
+ #clock-cells = <1>;
+ #reset-cells = <1>;
+ };
+
+ eth: ethernet@15100000 {
+ compatible = "mediatek,mt7988-eth", "syscon";
+ reg = <0 0x15100000 0 0x20000>;
+ mediatek,ethsys = <&ethdma>;
+ mediatek,sgmiisys = <&sgmiisys0>;
+ mediatek,usxgmiisys = <&usxgmiisys0>;
+ mediatek,xfi_pextp = <&xfi_pextp0>;
+ mediatek,xfi_pll = <&xfi_pll>;
+ mediatek,infracfg = <&topmisc>;
+ mediatek,toprgu = <&watchdog>;
+ resets = <&ethdma ETHDMA_FE_RST>, <&ethwarp ETHWARP_GSW_RST>;
+ reset-names = "fe", "mcm";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ mediatek,mcm;
+ status = "disabled";
+ };
+};
--- a/arch/arm/mach-mediatek/Kconfig
+++ b/arch/arm/mach-mediatek/Kconfig
@@ -58,6 +58,15 @@ config TARGET_MT7986
including UART, SPI, SPI flash, USB3.0, MMC, NAND, SNFI, PWM, PCIe,
Gigabit Ethernet, I2C, built-in 4x4 Wi-Fi, and PCIe.
+config TARGET_MT7988
+ bool "MediaTek MT7988 SoC"
+ select ARM64
+ select CPU
+ help
+ The MediaTek MT7988 is a ARM64-based SoC with a quad-core Cortex-A73.
+ including UART, SPI, SPI flash, USB3.0, MMC, NAND, SNFI, PWM, PCIe,
+ 10 Gigabit Ethernet , I2C, and PCIe.
+
config TARGET_MT8183
bool "MediaTek MT8183 SoC"
select ARM64
@@ -104,6 +113,7 @@ config SYS_BOARD
default "mt7629" if TARGET_MT7629
default "mt7981" if TARGET_MT7981
default "mt7986" if TARGET_MT7986
+ default "mt7988" if TARGET_MT7988
default "mt8183" if TARGET_MT8183
default "mt8512" if TARGET_MT8512
default "mt8516" if TARGET_MT8516
@@ -121,6 +131,7 @@ config SYS_CONFIG_NAME
default "mt7629" if TARGET_MT7629
default "mt7981" if TARGET_MT7981
default "mt7986" if TARGET_MT7986
+ default "mt7988" if TARGET_MT7988
default "mt8183" if TARGET_MT8183
default "mt8512" if TARGET_MT8512
default "mt8516" if TARGET_MT8516
@@ -135,7 +146,7 @@ config MTK_BROM_HEADER_INFO
string
default "media=nor" if TARGET_MT8518 || TARGET_MT8512 || TARGET_MT7622
default "media=emmc" if TARGET_MT8516 || TARGET_MT8365 || TARGET_MT8183
- default "media=snand;nandinfo=2k+64" if TARGET_MT7981 || TARGET_MT7986
+ default "media=snand;nandinfo=2k+64" if TARGET_MT7981 || TARGET_MT7986 || TARGET_MT7988
default "lk=1" if TARGET_MT7623
source "board/mediatek/mt7629/Kconfig"
--- a/arch/arm/mach-mediatek/Makefile
+++ b/arch/arm/mach-mediatek/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_TARGET_MT7623) += mt7623/
obj-$(CONFIG_TARGET_MT7629) += mt7629/
obj-$(CONFIG_TARGET_MT7981) += mt7981/
obj-$(CONFIG_TARGET_MT7986) += mt7986/
+obj-$(CONFIG_TARGET_MT7988) += mt7988/
obj-$(CONFIG_TARGET_MT8183) += mt8183/
obj-$(CONFIG_TARGET_MT8516) += mt8516/
obj-$(CONFIG_TARGET_MT8518) += mt8518/
--- /dev/null
+++ b/arch/arm/mach-mediatek/mt7988/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-y += init.o
+obj-y += lowlevel_init.o
--- /dev/null
+++ b/arch/arm/mach-mediatek/mt7988/init.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 MediaTek Inc.
+ * Author: Sam Shih <sam.shih@mediatek.com>
+ */
+
+#include <fdtdec.h>
+#include <init.h>
+#include <asm/armv8/mmu.h>
+#include <asm/global_data.h>
+#include <asm/u-boot.h>
+#include <asm/system.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define SZ_8G _AC(0x200000000, ULL)
+
+int dram_init(void)
+{
+ int ret;
+
+ ret = fdtdec_setup_mem_size_base();
+ if (ret)
+ return ret;
+
+ gd->ram_size = get_ram_size((void *)gd->ram_base, SZ_8G);
+
+ return 0;
+}
+
+int dram_init_banksize(void)
+{
+ gd->bd->bi_dram[0].start = gd->ram_base;
+ gd->bd->bi_dram[0].size = gd->ram_size;
+
+ return 0;
+}
+
+void reset_cpu(ulong addr)
+{
+ psci_system_reset();
+}
+
+static struct mm_region mt7988_mem_map[] = {
+ {
+ /* DDR */
+ .virt = 0x40000000UL,
+ .phys = 0x40000000UL,
+ .size = 0x200000000ULL,
+ .attrs = PTE_BLOCK_MEMTYPE(MT_NORMAL) | PTE_BLOCK_OUTER_SHARE,
+ }, {
+ .virt = 0x00000000UL,
+ .phys = 0x00000000UL,
+ .size = 0x40000000UL,
+ .attrs = PTE_BLOCK_MEMTYPE(MT_DEVICE_NGNRNE) |
+ PTE_BLOCK_NON_SHARE |
+ PTE_BLOCK_PXN | PTE_BLOCK_UXN
+ }, {
+ 0,
+ }
+};
+
+struct mm_region *mem_map = mt7988_mem_map;
--- /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