Hi Sahil,
Am 2021-11-17 19:11, schrieb Sahil Malhotra (OSS):
Could you please add some description what this is doing and for what this is intended? To have a "DTB overlay feature", it is enough to just enable CONFIG_OF_LIBFDT_OVERLAY.
I will add some description, and yes for DTB overlay feature, it is enough to enable CONFIG_OF_LIBFDT_OVERLAY but we need to do this step before booting the kernel that's why also have to enable CONFIG_OF_SYSTEM_SETUP.
Ok. What will the overlay do? Could you give an example?
Apparently you're adding an overlay passed by optee. Doesn't this have to be applied to u-boot's control dtb too?
Yes, we will be applying the overlay passed by optee, yes it will be applied to dtb which will be passed to uboot for kernel booting.
If I read this patch correctly, you're modifying the DT before you jump to linux. But I was asking whether you also have to modify the DT which is used by u-boot. Eg. if you disable some kind of crypto nodes (because optee will use them in secure world), this also have to communicated to u-boot, not only linux, no?
But until you've explained what this is about, this is only guesswork.
-michael