Helping building Android driver modules for STM32MP25 running OpenSTDroid

[ozi]

I've been trying to build compatible Android modules (.ko) for my STM32MP25F7-EV1 running OpenSTDroid Distribution. I've successfully built these modules, but I cannot enable them with the `insmod` command because they're incompatible.

insmod: ERROR: could not insert module btusb.ko: Exec format error

I ran `strings btusb.ko | grep vermagic` and it looks like the `btusb.ko` is using a slightly different kernel version than the target's kernel version (6.1.78-00024-ge4076639eb90 for module v.s. 6.1.78-00024-gf31b8a21afa8 for kernel).

vermagic=6.1.78-00024-ge4076639eb90 SMP preempt mod_unload aarch64
__UNIQUE_ID_vermagic330
__UNIQUE_ID_vermagic330

I don't understand where I'm going wrongly. Here's my module build process so far

1. Download OpenSTDroid Distribution (following the wiki linked here).
2. Build OpenSTDroid using the wiki linked here.
3. Set the following environment variables

export BUILD_TOP=$(pwd) /* AOSP root/top directory */
export ARCH=arm64 
export CROSS_COMPILE=aarch64-linux-gnu- 
export KERNEL_src=${BUILD_TOP}/device/stm/stm32mp2-kernel/linux-stm32mp2​

1. Ran `./device/stm/stm32mp2-kernel/source/load_kernel.sh` to load the kernel.
2. I entered `$KERNEL_SRC` and ran `make menuconfig` to enable the Bluetooth USB configuration options.
3. I ran `make olddefconfig`, `make prepare`, and then `make –C $KERNEL_SRC ARCH=$ARCH CROSS_COMPILE=$CROSS_COMPILE –j$(nrpoc)` to build the kernel.
4. Finally, I run `make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- M=drivers/bluetooth modules` to successfully build `btusb.ko`.

Am I in the wrong kernel folder? Am I building the module incorrectly? Any insight would be helpful.

Target Hardware Platform: STM32MP25F7-EV1

Target Operating System: OpenSTDroid Distribution (st-android-13.0.0-2024-07-31) [Wiki link]

Target Kernel Version: 6.1.78-00024-gf31b8a21afa8