On Tue, 2013-08-13 at 11:30 -0700, H. Peter Anvin wrote: > On 08/09/2013 08:38 AM, H. Peter Anvin wrote: > > On 08/09/2013 08:32 AM, James Bottomley wrote: > >> On Fri, 2013-08-09 at 08:23 -0700, H. Peter Anvin wrote: > >>> I would like to change the defaults for CONFIG_EFI and CONFIG_EFI_STUB > >>> to y. There is little reason to omit this since EFI now is a > >>> significant percentage of all systems. > >> > >> You didn't actually attach the patch, but I presume this is for 64 bit > >> compiles on x86 only? We still have significant problems getting 64 bit > >> EFI to interact with 32 bit kernels, so I don't believe we should enable > >> CONFIG_EFI globally for all of x86. > >> > > > > Well, it doesn't *solve* the problem with cross-mode, but it should work > > as-is for EFI32->32-bit kernel and EFI64->64-bit kernel. For the > > cross-mode kernels they will simply not do anything. > > > > Either way, nothing bad should come from it. The worst thing that will > > happen is that the kernel says "I don't have any EFI that I recognize." > > > > Cross-mode support will always require a secondary bootloader (since as > > far as I know there is no concept of "fat binaries" for EFI), but Matt > > Fleming is working on genuine cross-mode support for both the boot stub > > and (eventually) run time support. > > > > James, does this address your concerns? You mean for globally enabling CONFIG_EFI on x86? not really for 32 bit, you say above it's pretty much unusable; I'd prefer just to enable it for 64 bit. As you said in your original post "since EFI now is a significant percentage of all systems" but you actually mean EFI64 ... EFI32 is a pretty insignificant percentage of all systems. Can we actually boot a 32 bit kernel on an EFI64 system? The last time I tried on my Secure Boot SDV it wouldn't work; the problem is getting someting in the transfer of control path to boot the processor back to 32 bit mode. James -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
