On Tuesday 28 November 2006 13:46, bibo,mao wrote: > yes, x84_64EFI starts with 64-bit long mode and page enabled(virtual > address equals physical address) if it is x86_64 efi bios, it is defined in > section 2.3.4 of UEFI Specification Version 2.0. > > If kernel image is bzImage, x64 efi bootloader need switch to 32 bit > protect mode(or real mode) from 64 bit long mode, and if kernel image is > gzipped/plain format, efi bootloader can directly jump to 64-bit kernel > entry address without mode switch.
Thanks for your detailed information. So does it mean that GRUB needs to provide a PE32+ application to EFI, if it is on x86_64? Or does it understand PE32? More information is welcome. BTW, in the current implementation, GRUB skips real mode setup code in Linux and directly jumps to a protected mode entry on EFI. Can we use the same trick with bzImage on x86_64? Mode switching is not difficult, but if we can omit it, that would be much easier to implement. Okuji _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
