diff --git a/cmake/toolchain_IARARM.cmake b/cmake/toolchain_IARARM.cmake
new file mode 100644
index 0000000..48e34f9
--- /dev/null
+++ b/cmake/toolchain_IARARM.cmake
@@ -0,0 +1,178 @@
+#-------------------------------------------------------------------------------
+# Copyright (c) 2020, IAR Systems AB. All rights reserved.
+# Copyright (c) 2020, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+#-------------------------------------------------------------------------------
+
+cmake_minimum_required(VERSION 3.15)
+
+SET(CMAKE_SYSTEM_NAME Generic)
+set(CMAKE_SYSTEM_PROCESSOR       ${ARM_SYSTEM_PROCESSOR})
+set(CMAKE_SYSTEM_ARCHITECTURE    ${ARM_SYSTEM_ARCHITECTURE})
+
+if(CROSS_COMPILE)
+    set(CMAKE_C_COMPILER_TARGET      arm-${CROSS_COMPILE})
+    set(CMAKE_ASM_COMPILER_TARGET    arm-${CROSS_COMPILE})
+else()
+    set(CMAKE_C_COMPILER_TARGET      arm-arm-none-eabi)
+    set(CMAKE_ASM_COMPILER_TARGET    arm-arm-none-eabi)
+endif()
+
+set(CMAKE_C_COMPILER iccarm)
+set(CMAKE_ASM_COMPILER iasmarm)
+
+set(LINKER_VENEER_OUTPUT_FLAG --import_cmse_lib_out= )
+set(COMPILER_CMSE_FLAG --cmse)
+
+# This variable name is a bit of a misnomer. The file it is set to is included
+# at a particular step in the compiler initialisation. It is used here to
+# configure the extensions for object files. Despite the name, it also works
+# with the Ninja generator.
+set(CMAKE_USER_MAKE_RULES_OVERRIDE ${CMAKE_CURRENT_LIST_DIR}/set_extensions.cmake)
+
+macro(arm_toolchain_reset_compiler_flags)
+    set_property(DIRECTORY PROPERTY COMPILE_OPTIONS "")
+
+    add_compile_options(
+        $<$<COMPILE_LANGUAGE:C,CXX>:-e>
+        $<$<COMPILE_LANGUAGE:C,CXX>:--dlib_config=full>
+        $<$<COMPILE_LANGUAGE:C,CXX>:--vla>
+        $<$<COMPILE_LANGUAGE:C,CXX>:--silent>
+        $<$<COMPILE_LANGUAGE:C,CXX>:-DNO_TYPEOF>
+        $<$<COMPILE_LANGUAGE:C,CXX>:-D_NO_DEFINITIONS_IN_HEADER_FILES>
+        $<$<COMPILE_LANGUAGE:C,CXX>:--diag_suppress=Pe546,Pe940,Pa082,Pa084>
+    )
+endmacro()
+
+macro(arm_toolchain_reset_linker_flags)
+    set_property(DIRECTORY PROPERTY LINK_OPTIONS "")
+
+    add_link_options(
+      --silent
+      --semihosting
+      --redirect __write=__write_buffered
+    )
+endmacro()
+
+macro(arm_toolchain_set_processor_arch)
+    if(${ARM_SYSTEM_PROCESSOR} STREQUAL "cortex-m0plus")
+      set(CMAKE_SYSTEM_PROCESSOR Cortex-M0+)
+    else()
+      set(CMAKE_SYSTEM_PROCESSOR ${ARM_SYSTEM_PROCESSOR})
+    endif()
+    set(CMAKE_SYSTEM_ARCHITECTURE ${ARM_SYSTEM_ARCHITECTURE})
+
+    if (DEFINED ARM_SYSTEM_DSP)
+        if(NOT ARM_SYSTEM_DSP)
+            string(APPEND CMAKE_SYSTEM_PROCESSOR ".no_dsp")
+        endif()
+    endif()
+endmacro()
+
+macro(arm_toolchain_reload_compiler)
+    arm_toolchain_set_processor_arch()
+    arm_toolchain_reset_compiler_flags()
+    arm_toolchain_reset_linker_flags()
+
+    unset(CMAKE_C_FLAGS_INIT)
+    unset(CMAKE_C_LINK_FLAGS)
+    unset(CMAKE_ASM_FLAGS_INIT)
+    unset(CMAKE_ASM_LINK_FLAGS)
+
+    set(CMAKE_C_FLAGS_INIT "--cpu ${CMAKE_SYSTEM_PROCESSOR}")
+    set(CMAKE_ASM_FLAGS_INIT "--cpu ${CMAKE_SYSTEM_PROCESSOR}")
+    set(CMAKE_C_LINK_FLAGS "--cpu ${CMAKE_SYSTEM_PROCESSOR}")
+    set(CMAKE_ASM_LINK_FLAGS "--cpu ${CMAKE_SYSTEM_PROCESSOR}")
+
+    set(CMAKE_C_FLAGS ${CMAKE_C_FLAGS_INIT})
+    set(CMAKE_ASM_FLAGS ${CMAKE_ASM_FLAGS_INIT})
+endmacro()
+
+# Configure environment for the compiler setup run by cmake at the first
+# `project` call in <tfm_root>/CMakeLists.txt. After this mandatory setup is
+# done, all further compiler setup is done via arm_toolchain_reload_compiler()
+arm_toolchain_reload_compiler()
+
+# Behaviour for handling scatter files is so wildly divergent between compilers
+# that this macro is required.
+macro(target_add_scatter_file target)
+    target_link_options(${target}
+        PRIVATE
+        --config $<TARGET_OBJECTS:${target}_scatter>
+    )
+    add_dependencies(${target}
+        ${target}_scatter
+    )
+
+    add_library(${target}_scatter OBJECT)
+    foreach(scatter_file ${ARGN})
+        target_sources(${target}_scatter
+            PRIVATE
+                ${scatter_file}
+        )
+        # Cmake cannot use generator expressions in the
+        # set_source_file_properties command, so instead we just parse the regex
+        # for the filename and set the property on all files, regardless of if
+        # the generator expression would evaluate to true or not.
+        string(REGEX REPLACE ".*>:(.*)>$" "\\1" SCATTER_FILE_PATH "${scatter_file}")
+        set_source_files_properties(${SCATTER_FILE_PATH}
+            PROPERTIES
+            LANGUAGE C
+        )
+    endforeach()
+
+    target_link_libraries(${target}_scatter
+        platform_region_defs
+    )
+
+    target_compile_options(${target}_scatter
+        PRIVATE
+            --preprocess=sn $<TARGET_OBJECTS:${target}_scatter>
+    )
+endmacro()
+
+macro(add_convert_to_bin_target target)
+    get_target_property(bin_dir ${target} RUNTIME_OUTPUT_DIRECTORY)
+
+    add_custom_target(${target}_bin
+        SOURCES ${bin_dir}/${target}.bin
+    )
+    add_custom_command(OUTPUT ${bin_dir}/${target}.bin
+        DEPENDS ${target}
+        COMMAND ielftool
+            --silent
+            --bin $<TARGET_FILE:${target}>
+            ${bin_dir}/${target}.bin
+    )
+
+    add_custom_target(${target}_elf
+        SOURCES ${bin_dir}/${target}.elf
+    )
+    add_custom_command(OUTPUT ${bin_dir}/${target}.elf
+        DEPENDS ${target}
+        COMMAND ielftool
+            --silent
+            $<TARGET_FILE:${target}>
+            ${bin_dir}/${target}.elf
+    )
+
+    add_custom_target(${target}_hex
+        SOURCES ${bin_dir}/${target}.hex
+    )
+    add_custom_command(OUTPUT ${bin_dir}/${target}.hex
+        DEPENDS ${target}
+        COMMAND ielftool
+            --silent
+            --ihex $<TARGET_FILE:${target}>
+            ${bin_dir}/${target}.hex
+    )
+
+    add_custom_target(${target}_binaries
+        ALL
+        DEPENDS ${target}_bin
+        DEPENDS ${target}_elf
+        DEPENDS ${target}_hex
+    )
+endmacro()