boot: optee-os: enable RISC-V (64-bit) architecture

OP-TEE OS and TAs can run on RISC-V (64-bit) machines, so allow
optee-os to be compiled for the new architecture.

Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
[Arnout:
 - set CROSS_COMPILE_ta_rv64 even on arm builds;
 - ARCH=arm for aarch64.
]
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>

boot/optee-os/Config.in

@@ -1,6 +1,6 @@
 config BR2_TARGET_OPTEE_OS
 	bool "optee_os"
-	depends on BR2_ARM_CPU_ARMV8A || BR2_ARM_CPU_ARMV7A
+	depends on BR2_ARM_CPU_ARMV8A || BR2_ARM_CPU_ARMV7A || BR2_RISCV_64
 	help
 	  OP-TEE OS provides the secure world boot image and the trust
 	  application development kit of the OP-TEE project. OP-TEE OS

boot/optee-os/optee-os.mk

@@ -54,16 +54,26 @@ OPTEE_OS_MAKE_OPTS = \
 	CROSS_COMPILE_core="$(TARGET_CROSS)" \
 	CROSS_COMPILE_ta_arm64="$(TARGET_CROSS)" \
 	CROSS_COMPILE_ta_arm32="$(TARGET_CROSS)" \
+	CROSS_COMPILE_ta_rv64="$(TARGET_CROSS)" \
 	PYTHON3="$(HOST_DIR)/bin/python3"
 
+ifeq ($(BR2_riscv),y)
+OPTEE_OS_MAKE_OPTS += \
+	ARCH=riscv \
+	CFG_RV64_core=y \
+	CFG_USER_TA_TARGETS=ta_rv64
+else
 ifeq ($(BR2_aarch64),y)
 OPTEE_OS_MAKE_OPTS += \
+	ARCH=arm \
 	CFG_ARM64_core=y \
 	CFG_USER_TA_TARGETS=ta_arm64
 else
 OPTEE_OS_MAKE_OPTS += \
+	ARCH=arm \
 	CFG_ARM32_core=y
 endif
+endif
 
 # Get mandatory PLAFORM and optional PLATFORM_FLAVOR and additional
 # variables
@@ -77,6 +87,10 @@ OPTEE_OS_MAKE_OPTS += $(call qstrip,$(BR2_TARGET_OPTEE_OS_ADDITIONAL_VARIABLES))
 # root path otherwise the output directory path depends on the target
 # platform name.
 OPTEE_OS_BUILDDIR_OUT = out
+ifeq ($(BR2_riscv),y)
+OPTEE_OS_LOCAL_SDK = $(OPTEE_OS_BUILDDIR_OUT)/export-ta_rv64
+OPTEE_OS_SDK = $(STAGING_DIR)/lib/optee/export-ta_rv64
+endif
 ifeq ($(BR2_aarch64),y)
 OPTEE_OS_LOCAL_SDK = $(OPTEE_OS_BUILDDIR_OUT)/export-ta_arm64
 OPTEE_OS_SDK = $(STAGING_DIR)/lib/optee/export-ta_arm64