hello zephyr users

i'm using the stmf469i discovery board and i'm trying to enable some stm32 hal drivers but, try as i might, i cannot.

so for example, if i look in menuconfig for CONFIG_USE_STM32_HAL_DMA2D it appears but it is in red. if i press ? for information:

Name: USE_STM32_HAL_DMA2D
Type: bool
Value: n

Help:

  Enable STM32Cube Chrom-Art Accelerator™ controller (DMA2D) HAL module
  driver

Direct dependencies (=y):
     HAS_STM32CUBE(=y)

Kconfig definition, with parent deps. propagated to 'depends on'
================================================================

At modules/Kconfig.stm32:108
Included via /home/tristen/zephyrproject/zephyr/Kconfig:8 -> Kconfig.zephyr:10 -> modules/Kconfig:21
Menu path: (Top) -> Modules

  config USE_STM32_HAL_DMA2D
        bool
        depends on HAS_STM32CUBE(=y)
        help
          Enable STM32Cube Chrom-Art Accelerator™ controller (DMA2D) HAL module
          driver

working back it says it

HAS_STM32CUBE (=y)

SOC_SERIES_STM32F4X(=y)

yet i can't explicitly enable that specific CONFIG_USE_STM32_HAL_DMA2D and i can't include it in the prj.conf (errors about not being able to explicitly set it) and so i don't know what to do.

in my code i could

#include <stm32f4xx_hal_dma2d.h>

and compile without errors however the linking process failed whenever i tried to access a function, eg: HAL_DMA2D_Init. so it's like the environment knows i want to use that HAL and makes the include available to me, but i can't complete the build.

so i don't know if i'm getting hung up on the idea of whether linking will work if i could only enable CONFIG_USE_STM32_HAL_DMA2D or whether there is another way to get my project to compile/link the required hal driver, or indeed whether there are other options i'm not aware of.

when i look in 

zephyrproject/modules/hal/stm32/stm32cube/stm32f4xx/CMakeLists.txt

there is a whole lot of stuff about zephyr_library_sources_ifdef(CONFIG_USE_STM32_HAL_[all the things i would like to enable but cannot]) but the problem is i can't actually enable any of them.

anyway i tried google every which way and i'm stuck, so if anyone can help a brother out i'd be over the moon, cheers all, tristen.