add riscv gcc toolchain cmake

Change-Id: I1452618481d07810d19adeb8ad788c4ec4b6e2e4

Author: alex-spacemit

cmake/riscv64-spacemit-gcc.cmake

@@ -0,0 +1,38 @@
+# Copyright (c) 2023 SpacemiT. All rights reserved.
+set(CMAKE_SYSTEM_NAME Linux)
+SET(CMAKE_SYSTEM_PROCESSOR riscv64)
+set(CMAKE_SYSTEM_VERSION 1)
+
+if(CMAKE_HOST_SYSTEM_PROCESSOR MATCHES "^(riscv)")
+message(STATUS "HOST SYSTEM ${CMAKE_HOST_SYSTEM_PROCESSOR}")
+else()
+set(GNU_MACHINE riscv64-unknown-linux-gnu CACHE STRING "GNU compiler triple")
+if(DEFINED ENV{RISCV_ROOT_PATH})
+    file(TO_CMAKE_PATH $ENV{RISCV_ROOT_PATH} RISCV_ROOT_PATH)
+else()
+    message(FATAL_ERROR "RISCV_ROOT_PATH env must be defined")
+endif()
+
+set(RISCV_ROOT_PATH ${RISCV_ROOT_PATH} CACHE STRING "root path to riscv toolchain")
+set(CMAKE_C_COMPILER ${RISCV_ROOT_PATH}/bin/riscv64-unknown-linux-gnu-gcc)
+set(CMAKE_CXX_COMPILER ${RISCV_ROOT_PATH}/bin/riscv64-unknown-linux-gnu-g++)
+set(CMAKE_STRIP ${RISCV_ROOT_PATH}/bin/riscv64-unknown-linux-gnu-strip)
+set(CMAKE_FIND_ROOT_PATH "${RISCV_ROOT_PATH}/riscv64-unknown-linux-gnu")
+set(CMAKE_SYSROOT "${RISCV_ROOT_PATH}/sysroot")
+endif()
+
+if(NOT DEFINED CMAKE_CXX_FLAGS)
+    set(CMAKE_CXX_FLAGS "-march=rv64gcv_zfh_zba")
+endif()
+
+if(NOT DEFINED CMAKE_CXX_FLAGS)
+    set(CMAKE_C_FLAGS "-march=rv64gcv_zfh_zba")
+endif()
+
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
+set(CMAKE_C_FLAGS "-march=rv64gcv_zfh_zba -latomic -mabi=lp64d ${CMAKE_C_FLAGS}")
+set(CMAKE_CXX_FLAGS "-march=rv64gcv_zfh_zba -latomic -mabi=lp64d ${CXX_FLAGS}")
+add_definitions(-D__fp16=_Float16)