$ brew install cmake
$ $ cmake -version
cmake version 3.18.2

$ brew tap ArmMbed/homebrew-formulae
$ brew install arm-none-eabi-gcc
$ arm-none-eabi-gcc --version

arm-none-eabi-gcc (GNU Tools for Arm Embedded Processors 9-2019-q4-major) 9.2.1 20191025 (release) [ARM/arm-9-branch revision 277599]
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ brew install libusb dfu-util
$ dfu-util --version
dfu-util 0.9

$ brew install stlink
$ st-flash --version
v1.5.1

/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
  /* USER CODE END WHILE */
  LL_mDelay(100);
  LL_GPIO_TogglePin(LD3_GPIO_Port, LD3_Pin);
  LL_GPIO_TogglePin(LD4_GPIO_Port, LD4_Pin);
  LL_GPIO_TogglePin(LD5_GPIO_Port, LD5_Pin);
  LL_GPIO_TogglePin(LD6_GPIO_Port, LD6_Pin);
  /* USER CODE BEGIN 3 */
}

$ make
$ ls build
F407_CMake.bin
F407_CMake.elf
F407_CMake.hex
...

$ st-flash --format ihex write build/F407_CMake.hex

st-flash 1.6.1
2020-09-06T12:33:36 INFO common.c: F4xx: 192 KiB SRAM, 1024 KiB flash in at least 16 KiB pages.
2020-09-06T12:33:36 INFO common.c: Attempting to write 2308 (0x904) bytes to stm32 address: 134217728 (0x8000000)
EraseFlash - Sector:0x0 Size:0x4000 2020-09-06T12:33:36 INFO common.c: Flash page at addr: 0x08000000 erased
2020-09-06T12:33:36 INFO common.c: Finished erasing 1 pages of 16384 (0x4000) bytes
2020-09-06T12:33:36 INFO common.c: Starting Flash write for F2/F4/L4
2020-09-06T12:33:36 INFO flash_loader.c: Successfully loaded flash loader in sram
enabling 32-bit flash writes
size: 2308
2020-09-06T12:33:36 INFO common.c: Starting verification of write complete
2020-09-06T12:33:36 INFO common.c: Flash written and verified! jolly good!

$ dfu-util -a0 -d 0x0483:0xdf11 -s 0x08000000 -D build/F407_CMake.bin
dfu-util 0.9

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

dfu-util: Invalid DFU suffix signature
dfu-util: A valid DFU suffix will be required in a future dfu-util release!!!
Opening DFU capable USB device...
ID 0483:df11
Run-time device DFU version 011a
Claiming USB DFU Interface...
Setting Alternate Setting #0 ...
Determining device status: state = dfuERROR, status = 10
dfuERROR, clearing status
Determining device status: state = dfuIDLE, status = 0
dfuIDLE, continuing
DFU mode device DFU version 011a
Device returned transfer size 2048
DfuSe interface name: "Internal Flash  "
Downloading to address = 0x08000000, size = 2308
Download        [=========================] 100%         2308 bytes
Download done.
File downloaded successfully

cmake_minimum_required(VERSION 3.6)

set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
set(CMAKE_SYSTEM_NAME Generic)

# tool chain
set(CMAKE_C_COMPILER   arm-none-eabi-gcc)
set(CMAKE_ASM_COMPILER arm-none-eabi-gcc)
set(CMAKE_CXX_COMPILER arm-none-eabi-g++)
set(CMAKE_EXE_LINKER   arm-none-eabi-g++)
set(OBJCOPY            arm-none-eabi-objcopy)
set(SIZE               arm-none-eabi-size)

# project
project(F407_CMake)

set(ELF_FILE ${PROJECT_NAME}.elf)
set(HEX_FILE ${PROJECT_NAME}.hex)
set(BIN_FILE ${PROJECT_NAME}.bin)
set(MAP_FILE ${PROJECT_NAME}.map)

# mpu
set(CPU       cortex-m4)
set(FPU       -mfpu=fpv4-sp-d16)
set(FLOAT_ABI -mfloat-abi=hard)
set(LDSCRIPT  STM32F407VGTx_FLASH.ld)

# compiler options
add_compile_options(-O2)
add_compile_options(-Wall)
add_compile_options(-ffunction-sections)
add_compile_options(-fdata-sections)
add_compile_options(-fstack-usage)

set(CMAKE_C_FLAGS "-mcpu=${CPU} -std=gnu11 ${FPU} ${FLOAT_ABI} -mthumb")
set(CMAKE_CXX_FLAGS "-mcpu=${CPU} -std=gnu++14 -fno-use-cxa-atexit ${FPU} ${FLOAT_ABI} -mthumb")
set(CMAKE_AS_FLAGS "-mcpu=${CPU} -x assembler-with-cpp ${FPU} ${FLOAT_ABI} -mthumb")
set(CMAKE_EXE_LINKER_FLAGS "-mcpu=${CPU} -T${CMAKE_CURRENT_SOURCE_DIR}/${LDSCRIPT} --specs=nosys.specs -Wl,-Map=${MAP_FILE} -Wl,--gc-sections -static --specs=nano.specs ${FPU} ${FLOAT_ABI} -mthumb -Wl,--start-group -lc -lm -lstdc++ -lsupc++ -Wl,--end-group")

enable_language(ASM)

# define
add_definitions(-DUSE_FULL_LL_DRIVER)
add_definitions(-DPREFETCH_ENABLE=1)
add_definitions(-DINSTRUCTION_CACHE_ENABLE=1)
add_definitions(-DDATA_CACHE_ENABLE=1)
add_definitions(-DSTM32F407xx)

# includes
include_directories(
    Core/Inc
    Drivers/STM32F4xx_HAL_Driver/Inc
    Drivers/CMSIS/Device/ST/STM32F4xx/Include
    Drivers/CMSIS/Include
)

# sources
file(GLOB SRCS
    Core/Src/main.c
    Core/Src/stm32f4xx_it.c
    Drivers/STM32F4xx_HAL_Driver/Src/stm32f4xx_ll_gpio.c
    Drivers/STM32F4xx_HAL_Driver/Src/stm32f4xx_ll_rcc.c
    Drivers/STM32F4xx_HAL_Driver/Src/stm32f4xx_ll_utils.c
    Drivers/STM32F4xx_HAL_Driver/Src/stm32f4xx_ll_exti.c
    Core/Src/system_stm32f4xx.c
    startup_stm32f407xx.s
)

# executables
add_executable(${ELF_FILE} ${SRCS})

add_custom_command(TARGET ${ELF_FILE} POST_BUILD
    COMMAND ${OBJCOPY} -Obinary ${ELF_FILE} ${BIN_FILE}
    COMMAND ${OBJCOPY} -Oihex   ${ELF_FILE} ${HEX_FILE}
    COMMAND ${SIZE} --format=berkeley ${ELF_FILE} ${HEX_FILE}
    COMMENT "Invoking: Cross ARM GNU Print Size"
)

$ mkdir out
$ cd out
$ cmake ..
$ make
$ ls

CMakeCache.txt          F407_CMake.bin          F407_CMake.hex          Makefile
CMakeFiles              F407_CMake.elf          F407_CMake.map          cmake_install.cmake