Updates for the x86 boot process: - Initialize FPU late. Right now FPU is initialized very early during boot. There is no real requirement to do so. The only requirement is to have it done before alternatives are patched. That's done in check_bugs() which does way more than what the function name suggests. So first rename check_bugs() to arch_cpu_finalize_init() which makes it clear what this is about. Move the invocation of arch_cpu_finalize_init() earlier in start_kernel() as it has to be done before fork_init() which needs to know the FPU register buffer size. With those prerequisites the FPU initialization can be moved into arch_cpu_finalize_init(), which removes it from the early and fragile part of the x86 bringup.