diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0f20309e19..54679be438 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,15 @@
 cmake_minimum_required(VERSION 3.17)
 
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+
+set(MAIN_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
+set(MAIN_LIB_DIR "${CMAKE_CURRENT_SOURCE_DIR}/lib")
+set(MAIN_UTILS_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src/utils")
+set(MAIN_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src/main")
+set(SVD_DIR "${CMAKE_CURRENT_SOURCE_DIR}/dev/svd")
+set(DOWNLOADS_DIR "${MAIN_DIR}/downloads")
+set(TOOLS_DIR "${MAIN_DIR}/tools")
+
 set(TOOLCHAIN_OPTIONS none arm-none-eabi)
 set(TOOLCHAIN "arm-none-eabi" CACHE STRING "Toolchain to use. Available: ${TOOLCHAIN_OPTIONS}")
 set_property(CACHE TOOLCHAIN PROPERTY STRINGS ${TOOLCHAIN_OPTIONS})
@@ -14,6 +24,7 @@ if(TOOLCHAIN STREQUAL none)
     add_subdirectory(src/test)
 else()
     set(CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_SOURCE_DIR}/cmake/${TOOLCHAIN}.cmake")
+    include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/${TOOLCHAIN}-checks.cmake")
 endif()
 
 if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
@@ -37,13 +48,6 @@ if (NOT RUBY_EXECUTABLE)
 endif()
 
 
-set(MAIN_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
-set(MAIN_LIB_DIR "${CMAKE_CURRENT_SOURCE_DIR}/lib")
-set(MAIN_UTILS_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src/utils")
-set(MAIN_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src/main")
-set(SVD_DIR "${CMAKE_CURRENT_SOURCE_DIR}/dev/svd")
-
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
 include(GetGitRevisionDescription)
 get_git_head_revision(GIT_REFSPEC GIT_SHA1)
diff --git a/cmake/arm-none-eabi-checks.cmake b/cmake/arm-none-eabi-checks.cmake
new file mode 100644
index 0000000000..2faf08bc00
--- /dev/null
+++ b/cmake/arm-none-eabi-checks.cmake
@@ -0,0 +1,110 @@
+include(gcc)
+set(arm_none_eabi_triplet "arm-none-eabi")
+
+# Keep version in sync with the distribution files below
+set(arm_none_eabi_gcc_version "9.2.1")
+set(arm_none_eabi_base_url "https://developer.arm.com/-/media/Files/downloads/gnu-rm/9-2019q4/gcc-arm-none-eabi-9-2019-q4-major")
+# suffix and sha1
+set(arm_none_eabi_win32 "win32.zip" 60f364ecf2e8717a58d352db95b388eee508b727)
+set(arm_none_eabi_linux_amd64 "x86_64-linux.tar.bz2" 3829ff61b2601c6cf061a5a275c2538a96a8d521)
+set(arm_none_eabi_linux_aarch64 "aarch64-linux.tar.bz2" fdb6fe7058927ad897f63d2d245f825a9587a1c5)
+set(arm_none_eabi_gcc_macos "mac.tar.bz2" 26fe33e0c25d9a2947c0373ea48c00ef46eacd58)
+
+function(arm_none_eabi_gcc_distname var)
+    string(REPLACE "/" ";" url_parts ${arm_none_eabi_base_url})
+    list(LENGTH url_parts n)
+    math(EXPR last "${n} - 1")
+    list(GET url_parts ${last} basename)
+    set(${var} ${basename} PARENT_SCOPE)
+endfunction()
+
+function(host_uname_machine var)
+    # We need to call uname -m manually, since at the point
+    # this file is included CMAKE_HOST_SYSTEM_PROCESSOR is
+    # empty because we haven't called project() yet.
+    execute_process(COMMAND uname -m
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+        OUTPUT_VARIABLE machine)
+
+    set(${var} ${machine} PARENT_SCOPE)
+endfunction()
+
+function(arm_none_eabi_gcc_install)
+    set(dist "")
+    if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
+        set(dist ${arm_none_eabi_win32})
+    elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux")
+        host_uname_machine(machine)
+        if(machine STREQUAL "x86_64")
+            set(dist ${arm_none_eabi_linux_amd64})
+        elseif(machine STREQUAL "aarch64")
+            set(dist ${arm_none_eabi_linux_aarch64})
+        else()
+            message("-- no precompiled ${arm_none_eabi_triplet} toolchain for machine ${machine}")
+        endif()
+    elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin")
+        set(dist ${arm_none_eabi_gcc_macos})
+    endif()
+
+    if(dist STREQUAL "")
+        message(FATAL_ERROR "could not install ${arm_none_eabi_triplet}-gcc automatically")
+    endif()
+    list(GET dist 0 dist_suffix)
+    list(GET dist 1 dist_sha1)
+    set(dist_url "${arm_none_eabi_base_url}-${dist_suffix}")
+    string(REPLACE "/" ";" url_parts ${dist_url})
+    list(LENGTH url_parts n)
+    math(EXPR last "${n} - 1")
+    list(GET url_parts ${last} basename)
+    set(output "${DOWNLOADS_DIR}/${basename}")
+    message("-- downloading ${arm_none_eabi_triplet}-gcc ${arm_none_eabi_gcc_version} from ${dist_url}")
+    file(DOWNLOAD ${dist_url} ${output}
+        INACTIVITY_TIMEOUT 30
+        STATUS status
+        SHOW_PROGRESS
+        EXPECTED_HASH SHA1=${dist_sha1}
+        TLS_VERIFY ON
+    )
+    list(GET status 0 status_code)
+    if(NOT status_code EQUAL 0)
+        list(GET status 1 status_message)
+        message(FATAL_ERROR "error downloading ${basename}: ${status_message}")
+    endif()
+    message("-- extracting ${basename}")
+    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${TOOLS_DIR})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E tar xf ${output}
+        RESULT_VARIABLE status
+        WORKING_DIRECTORY ${TOOLS_DIR}
+    )
+    if(NOT status EQUAL 0)
+        message(FATAL_ERROR "error extracting ${basename}: ${status}")
+    endif()
+endfunction()
+
+function(arm_none_eabi_gcc_add_path)
+    arm_none_eabi_gcc_distname(dist_name)
+    set(gcc_path "${TOOLS_DIR}/${dist_name}/bin")
+    set(ENV{PATH} "$ENV{PATH}:${gcc_path}")
+endfunction()
+
+function(arm_none_eabi_gcc_check)
+    gcc_get_version(version
+        TRIPLET ${arm_none_eabi_triplet}
+        PROGRAM_NAME prog
+        PROGRAM_PATH prog_path
+    )
+    if(NOT version)
+        message("-- could not find ${prog}")
+        arm_none_eabi_gcc_install()
+        return()
+    endif()
+    message("-- found ${prog} ${version} at ${prog_path}")
+    if(NOT arm_none_eabi_gcc_version STREQUAL version)
+        message("-- expecting ${prog} version ${arm_none_eabi_gcc_version}, but got version ${version} instead")
+        arm_none_eabi_gcc_install()
+        return()
+    endif()
+endfunction()
+
+arm_none_eabi_gcc_add_path()
+arm_none_eabi_gcc_check()
\ No newline at end of file
diff --git a/cmake/arm-none-eabi.cmake b/cmake/arm-none-eabi.cmake
index e86cb6a507..eb7ddebabf 100644
--- a/cmake/arm-none-eabi.cmake
+++ b/cmake/arm-none-eabi.cmake
@@ -6,35 +6,16 @@ if(WIN32)
 endif()
 
 set(TARGET_TRIPLET "arm-none-eabi")
-set(gcc "${TARGET_TRIPLET}-gcc${TOOL_EXECUTABLE_SUFFIX}")
-
-find_program(GCC "${gcc}")
-if (NOT GCC)
-    message(FATAL_ERROR "Could not find ${gcc}")
-endif()
-
-set(ARM_NONE_EABI_GCC_VERSION 9.2.1)
-
-execute_process(COMMAND "${GCC}" -dumpversion
-    OUTPUT_STRIP_TRAILING_WHITESPACE
-    OUTPUT_VARIABLE GCC_VERSION)
-
-if (NOT ${ARM_NONE_EABI_GCC_VERSION} STREQUAL ${GCC_VERSION})
-    # TODO: Show how to override on cmdline or install builtin compiler
-    message(FATAL_ERROR "Expecting gcc version ${ARM_NONE_EABI_GCC_VERSION}, but found ${GCC_VERSION}")
-endif()
-
-get_filename_component(TOOLCHAIN_BIN_DIR "${GCC}" DIRECTORY)
 
 set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
-set(CMAKE_ASM_COMPILER "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-gcc${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "asm compiler")
-set(CMAKE_C_COMPILER "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-gcc${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "c compiler")
-set(CMAKE_CXX_COMPILER "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-g++${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "c++ compiler")
-set(CMAKE_OBJCOPY "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-objcopy${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "objcopy tool")
-set(CMAKE_OBJDUMP "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-objdump${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "objdump tool")
-set(CMAKE_SIZE "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-size${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "size tool")
-set(CMAKE_DEBUGGER "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-gdb${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "debugger")
-set(CMAKE_CPPFILT "${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-c++filt${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "c++filt")
+set(CMAKE_ASM_COMPILER "${TARGET_TRIPLET}-gcc${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "asm compiler")
+set(CMAKE_C_COMPILER "${TARGET_TRIPLET}-gcc${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "c compiler")
+set(CMAKE_CXX_COMPILER "${TARGET_TRIPLET}-g++${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "c++ compiler")
+set(CMAKE_OBJCOPY "${TARGET_TRIPLET}-objcopy${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "objcopy tool")
+set(CMAKE_OBJDUMP "${TARGET_TRIPLET}-objdump${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "objdump tool")
+set(CMAKE_SIZE "${TARGET_TRIPLET}-size${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "size tool")
+set(CMAKE_DEBUGGER "${TARGET_TRIPLET}-gdb${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "debugger")
+set(CMAKE_CPPFILT "${TARGET_TRIPLET}-c++filt${TOOL_EXECUTABLE_SUFFIX}" CACHE INTERNAL "c++filt")
 set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
diff --git a/cmake/gcc.cmake b/cmake/gcc.cmake
new file mode 100644
index 0000000000..cfe2ddf3db
--- /dev/null
+++ b/cmake/gcc.cmake
@@ -0,0 +1,34 @@
+function(gcc_get_version var)
+    cmake_parse_arguments(args
+        ""
+        "TRIPLET;PROGRAM_NAME;PROGRAM_PATH"
+        ""
+        ${ARGN}
+    )
+    set(prog "gcc")
+    if(args_TRIPLET)
+        set(prog "${args_TRIPLET}-${prog}")
+    endif()
+    if(args_PROGRAM_NAME)
+        set(${args_PROGRAM_NAME} ${prog} PARENT_SCOPE)
+    endif()
+
+    find_program(gcc ${prog})
+    if (NOT gcc)
+        set(${var} OFF PARENT_SCOPE)
+    endif()
+
+    if(args_PROGRAM_PATH)
+        set(${args_PROGRAM_PATH} ${gcc} PARENT_SCOPE)
+    endif()
+
+    execute_process(COMMAND "${gcc}" -dumpversion
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+        OUTPUT_VARIABLE version)
+
+    if("" STREQUAL version)
+        set(${var} OFF PARENT_SCOPE)
+    else()
+        set(${var} ${version} PARENT_SCOPE)
+    endif()
+endfunction()
diff --git a/cmake/settings.cmake b/cmake/settings.cmake
index d3e3db8f3a..17d48168b4 100644
--- a/cmake/settings.cmake
+++ b/cmake/settings.cmake
@@ -18,7 +18,7 @@ function(enable_settings exe name)
     add_custom_command(
         OUTPUT ${dir}/${SETTINGS_GENERATED_H} ${dir}/${SETTINGS_GENERATED_C}
         COMMAND
-            ${CMAKE_COMMAND} -E env CFLAGS="${cflags}" TARGET=${name}
+            ${CMAKE_COMMAND} -E env CFLAGS="${cflags}" TARGET=${name} PATH=$ENV{PATH}
             ${RUBY_EXECUTABLE} ${SETTINGS_GENERATOR} ${MAIN_DIR} ${SETTINGS_FILE} -o "${dir}"
         DEPENDS ${SETTINGS_GENERATOR} ${SETTINGS_FILE}
     )
diff --git a/cmake/stm32.cmake b/cmake/stm32.cmake
index 23fb723333..f028a3fdc2 100644
--- a/cmake/stm32.cmake
+++ b/cmake/stm32.cmake
@@ -192,13 +192,15 @@ endfunction()
 
 function(add_hex_target name exe hex)
     add_custom_target(${name} ALL
+        cmake -E env PATH=$ENV{PATH}
         ${CMAKE_OBJCOPY} -Oihex $<TARGET_FILE:${exe}> ${hex}
         BYPRODUCTS ${hex}
     )
 endfunction()
 
 function(add_bin_target name exe bin)
-    add_custom_target(${name} ALL
+    add_custom_target(${name}
+        cmake -E env PATH=$ENV{PATH}
         ${CMAKE_OBJCOPY} -Obinary $<TARGET_FILE:${exe}> ${bin}
         BYPRODUCTS ${bin}
     )