Messages in this thread | | | Date | Mon, 9 Feb 2015 12:23:15 -0800 | Subject | Re: [PATCH] x86, boot: Allow 64bit EFI kernel to be loaded above 4G | From | Yinghai Lu <> |
| |
On Mon, Feb 9, 2015 at 10:27 AM, Matt Fleming <matt@codeblueprint.co.uk> wrote: > On Tue, 03 Feb, at 06:03:20PM, Yinghai Lu wrote: > > The first thing that comes to mind is the issues we experienced last > year when adding support for loading initrds above 4GB to the EFI boot > stub, c.f. commit 47226ad4f4cf ("x86/efi: Only load initrd above 4g on > second try"). > > Are things going to work correctly this time?
That should be addressed the grub2.
I was thinking that we may need to add mem_limit command together with linuxefi and initrdefi. or add linuxefi64/initrdefi64?
BTW, I tested loading kernel above grub2 on virutalbox, qemu/kvm/OVMF, and real servers (ami ...) all work without problem.
wonder if we need have one black list for 64bit UEFI that does not support access memory above 4G.
>> @@ -1430,9 +1431,12 @@ struct boot_params *efi_main(struct efi_ >> * If the kernel isn't already loaded at the preferred load >> * address, relocate it. >> */ >> - if (hdr->pref_address != hdr->code32_start) { >> - unsigned long bzimage_addr = hdr->code32_start; >> - status = efi_relocate_kernel(sys_table, &bzimage_addr, >> + loaded_addr = hdr->code32_start; >> + loaded_addr |= (unsigned long)hdr->ext_code32_start << 32; > > Please compile this for CONFIG_X86_32 and fix any compiler warnings.
Ok.
> >> @@ -738,6 +742,13 @@ Offset/size: 0x264/4 >> >> See EFI HANDOVER PROTOCOL below for more details. >> >> +Field name: ext_code32_start >> +Type: modify (optional, reloc) >> +Offset/size: 0x268/4 >> +Protocol: 2.14+ >> + >> + The address is used with code32_start to compare pref_address >> + to support EFI 64bit kernel get loaded above 4G. > > It would be good to mention that this new field contains the upper > 32-bits of the 64-bit address.
ok. that is: upper 32bits of the 64bit address of startup_32 when kernel loaded above 4G.
Thanks
Yinghai
| |