MLECO-1860: Support for Arm GNU Embedded Toolchain

This patch enables compilation of ML use cases bare-metal applications
using Arm GNU Embedded Toolchain. The GNU toolchain can be used instead
of the Arm Compiler that was already supported.

The GNU toolchain is also set as the default toolchain when building
applications for the MPS3 target.

Note: The version of GNU toolchain must be 10.2.1 or higher.

Change-Id: I5fff242f0f52d2db6c75d292f9fa990df1aec978
Signed-off-by: Kshitij Sisodia <kshitij.sisodia@arm.com>

1 files changed, 22 insertions, 20 deletions

diff --git a/scripts/cmake/bare-metal-sources.cmake b/scripts/cmake/bare-metal-sources.cmake
index 8b348e3..2bfe616 100644
--- a/scripts/cmake/bare-metal-sources.cmake
+++ b/scripts/cmake/bare-metal-sources.cmake
@@ -28,13 +28,15 @@ set(SOURCE_GEN_DIR          ${CMAKE_BINARY_DIR}/generated/bsp)
 if (NOT DEFINED MEM_PROFILES_SRC_DIR)
     set(MEM_PROFILES_SRC_DIR    ${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/subsystem-profiles)
 endif()
+
 set(MEM_PROFILE_TEMPLATE    ${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/templates/peripheral_memmap.h.template)
 set(IRQ_PROFILE_TEMPLATE    ${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/templates/peripheral_irqs.h.template)
 set(MEM_REGIONS_TEMPLATE    ${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/templates/mem_regions.h.template)
 set(TA_SETTINGS_TEMPLATE    ${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake/templates/timing_adapter_settings.template)
+set(LINKER_SCRIPT_DIR       "${PLAT_HAL}/bsp/mem_layout")
 set(TENSORFLOW_LITE_MICRO_PLATFORM_LIB_NAME  "libtensorflow-microlite.a")
 set(TENSORFLOW_LITE_MICRO_FLAG               "-DTF_LITE_STATIC_MEMORY")
-set(ETHOS_U55_FLAG          "-DARM_NPU=1")
+set(ETHOS_U55_FLAG                           "-DARM_NPU=1")
 
 if (ETHOS_U55_ENABLED)
     set(OPTIONAL_FLAGS      "${OPTIONAL_FLAGS} ${ETHOS_U55_FLAG}")
@@ -54,23 +56,33 @@ if (TARGET_PLATFORM STREQUAL mps3)
     if (TARGET_SUBSYSTEM STREQUAL sse-300)
         message(STATUS          "target subsystem is ${TARGET_SUBSYSTEM}")
         set(BSP_PACKAGE_DIR     "${PLAT_HAL}/bsp/bsp-packs/mps3")
-        set(SCAT_FILE           "${PLAT_HAL}/bsp/mem_layout/mps3-${TARGET_SUBSYSTEM}.sct")
+        set(LINKER_SCRIPT_NAME  "${TARGET_PLATFORM}-${TARGET_SUBSYSTEM}")
 
         # Include the mem profile definitions specific to our target subsystem
         include(${MEM_PROFILES_SRC_DIR}/corstone-${TARGET_SUBSYSTEM}.cmake)
         set(OPTIONAL_FLAGS      "${OPTIONAL_FLAGS} ${MPS3_PLATFORM_FLAG}")
+
+        # For deployment on the MPS3 FPGA platform, we need to produce
+        # two bin files - one that is loaded into the ITCM, and another
+        # that is loaded into the DDR region.
+        set(MPS3_SECTION_PATTERNS   "*.at_itcm" "*.at_ddr")
+        set(MPS3_OUTPUT_BIN_NAMES   "itcm.bin"  "ddr.bin")
+        set(MPS3_FPGA_CONFIG        "${CMAKE_CURRENT_SOURCE_DIR}/scripts/${TARGET_PLATFORM}/${TARGET_SUBSYSTEM}/images.txt")
     else ()
         message(FATAL_ERROR "Non compatible target subsystem: ${TARGET_SUBSYSTEM}")
     endif ()
 elseif (TARGET_PLATFORM STREQUAL simple_platform)
     set(BSP_PACKAGE_DIR     "${PLAT_HAL}/bsp/bsp-packs/${TARGET_PLATFORM}")
-    set(SCAT_FILE           "${PLAT_HAL}/bsp/mem_layout/${TARGET_PLATFORM}.sct")
+    set(LINKER_SCRIPT_NAME  "${TARGET_PLATFORM}")
     include(${MEM_PROFILES_SRC_DIR}/${TARGET_PLATFORM}.cmake)
     set(OPTIONAL_FLAGS      "${OPTIONAL_FLAGS}")
 else ()
     message(FATAL_ERROR "Non compatible target platform ${TARGET_PLATFORM}")
 endif ()
 
+# Add link options for the linker script to be used:
+add_linker_script(${LINKER_SCRIPT_DIR} ${LINKER_SCRIPT_NAME})
+
 if (ETHOS_U55_ENABLED)
     USER_OPTION(TA_CONFIG_FILE "Path to the timing adapter configuration file"
             "${CMAKE_SCRIPTS_DIR}/ta_config.cmake"
@@ -91,7 +103,6 @@ configure_file("${IRQ_PROFILE_TEMPLATE}" "${SOURCE_GEN_DIR}/peripheral_irqs.h")
 configure_file("${MEM_REGIONS_TEMPLATE}" "${SOURCE_GEN_DIR}/mem_regions.h")
 configure_file("${TA_SETTINGS_TEMPLATE}" "${SOURCE_GEN_DIR}/timing_adapter_settings.h")
 
-message(STATUS "Scatter file: ${SCAT_FILE}")
 message(STATUS "Using BSP package from: ${BSP_PACKAGE_DIR}")
 
 if (DEFINED VERIFY_TEST_OUTPUT)
@@ -114,27 +125,14 @@ if (DEFINED ARMCLANG_DEBUG_DWARF_LEVEL)
     set(OPTIONAL_FLAGS "${OPTIONAL_FLAGS} -gdwarf-${ARMCLANG_DEBUG_DWARF_LEVEL}")
 endif()
 
-set(COMPILER_FLAGS              "${ALL_COMMON_FLAGS} ${TENSORFLOW_LITE_MICRO_FLAG} ${PROFILING_OPT} ${OPTIONAL_FLAGS}")
+set(COMPILER_FLAGS              "${TENSORFLOW_LITE_MICRO_FLAG} ${PROFILING_OPT} ${OPTIONAL_FLAGS}")
 # For some reason, cmake doesn't pass the c++ standard flag, adding it manually
 set(CMAKE_CXX_FLAGS             "${COMPILER_FLAGS} -std=c++11" CACHE INTERNAL "")
 set(CMAKE_C_FLAGS               "${COMPILER_FLAGS}" CACHE INTERNAL "")
-set(CMAKE_ASM_FLAGS             "${CPU_LD}")
 set(CMAKE_ASM_COMPILE_OBJECT    ${CMAKE_CXX_FLAGS})
 
-add_link_options(--strict --callgraph --load_addr_map_info --map)
-add_link_options(--symbols --xref --scatter=${SCAT_FILE})
-
-# Warnings to be ignored:
-# L6314W = No section matches pattern
-# L6439W = Multiply defined Global Symbol
-add_link_options(--diag_suppress=L6439W,L6314W)
-add_link_options(--info sizes,totals,unused,veneers --entry Reset_Handler)
-
-if (CMAKE_BUILD_TYPE STREQUAL Release)
-    add_link_options(--no_debug)
-endif ()
-
-set(CMAKE_EXE_LINKER_FLAGS "${CPU_LD}")
+# Tell linker that reset interrupt handler is our entry point
+add_link_options(--entry Reset_Handler)
 
 set(PLAT_BSP_INCLUDES
     ${PLAT_HAL}/bsp/cmsis-device/include
@@ -168,3 +166,7 @@ file(GLOB_RECURSE SRC_PLAT_HAL
     "${PLAT_HAL}/bsp/bsp-core/*.c"
     "${BSP_PACKAGE_DIR}/*.c"
     )
+
+# Special retarget source to direct stdin, stdout and stderr streams to the
+# UART block.
+set(PLAT_RETARGET_SOURCE "${PLAT_HAL}/bsp/bsp-core/retarget.c")