Hi Aiden, On Tue, 21 Apr 2020 at 18:45, <aiden.p...@intel.com> wrote: > > From: Aiden Park <aiden.p...@intel.com> > > This will allow a board or cpu to do its specific initialization > at 64-bit entry if U-Boot is a pure 64-bit binary. > > Signed-off-by: Aiden Park <aiden.p...@intel.com> > --- > arch/x86/cpu/start64.S | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/x86/cpu/start64.S b/arch/x86/cpu/start64.S > index 7be834788b..b8ac5aab57 100644 > --- a/arch/x86/cpu/start64.S > +++ b/arch/x86/cpu/start64.S > @@ -13,6 +13,11 @@ > .globl _start > .type _start, @function > _start: > +#if defined(CONFIG_X86_RUN_64BIT_ONLY) > + jmp init_64bit_entry > +.globl init_64bit_entry_ret > +init_64bit_entry_ret: > +#endif
Would it be safe to do this always? Is that a standard register to have the HOB pointer be in? If so, we could always store it. We could also make sure that U-Boot passes it on too. Note that U-Boot has a struct arch_spl_handoff which is how it passes the HOB through. > /* Set up memory using the existing stack */ > mov %rsp, %rdi > call board_init_f_alloc_reserve > -- > 2.20.1 > Regards, Simon