How to profile the kernel during its initialization?

[Zheng Da]

Hello

Can we profile the kernel during its initialization? perf is
initialized in an early stage in start_kernel(), but it seems there
are no command-line parameters to enable it.
Does anyone have any ideas how to profile the kernel during its
initialization (before user space programs start to run)? I think
someone should have the similar problem as me, and there should be
some solutions.

Thanks,
Da