if you want to compiler some xxx.bb only, you just bitbake xxx
Ques
maybe be meet some problem when you first build the image, and you should execute git config --global --add safe.directory "*" and then bitbake fsl-image-auto
Notice
If the driver or files you want to add has no .bb file(xxx.bb), and you must add a xxx.bb file in the correct directory, for example:
bitbake fsl-image-auto and generate the current osal-kernel-lib folder, and then enter osal-kernel-lib/1.0-r0/git/, and then git add ., and git commit -m "111" to record the current commit generated, and now you can add your own neccessary file(./FDMA/fdma_driver_module.c ./FDMA/fdma_driver_module.h and /FDMA/Makefile), and generate the patch file to use git diff > fdma-add.patch.
add fdma-driver.bb under meta-test/recipes-kernel/fdma/fdma-driver.bb second
and then add fdma-add.patch under meta-test/recipes-kernel/rsdk/files/fdma-add.patch
and next is add file://fdma-add.patch\ into osal-kernel-lib.bbappend under meta-test/recipes-kernel/rsdk/osal-kernel-lib.bbappend
and the last you can bitbake fdma-driver to build the fdma_driver.ko only.
Tips
If the m7-sample added into project under resources/m7-sample and resources/arm-none-eabi-10-2020-q4-major-x86_64-linux.tar.bz2, and then you can build the m7-sample.bb by bitbake m7-sample genarate the m7-sample under build_37/tmp/work/cortexa53-crypto-fsl-linux/m7-sample. But if you want to rebuild the m7-sample.bb, you must be excute bitbake m7-sample -c do_compile -f command to rebuild it. And if you want to change or add some code in m7-sample, you must modified the m7-sample under build_37/tmp/work/cortexa53-crypto-fsl-linux/m7-sample/1.0-r0/git and then it will be enable to compile to your m7-sample.bb results.