On Fri, 2013-12-06 at 12:25 +0000, Grant Likely wrote: > On Thu, 5 Dec 2013 15:28:06 +0000, Catalin Marinas <catalin.marinas@xxxxxxx> wrote: > > On Thu, Dec 05, 2013 at 02:43:23PM +0000, Mark Salter wrote: > > > On Thu, 2013-12-05 at 14:18 +0000, Catalin Marinas wrote: > > > > On Fri, Nov 29, 2013 at 10:05:10PM +0000, Mark Salter wrote: > > > > > This patch adds PE/COFF header fields to the start of the Image > > > > > so that it appears as an EFI application to EFI firmware. An EFI > > > > > stub is included to allow direct booting of the kernel Image. Due > > > > > to EFI firmware limitations, only little endian kernels with 4K > > > > > page sizes are supported at this time. > > > > > > > > I don't fully understand the EFI firmware limitations but for big endian > > > > we could have the EFI_STUB wrapper in little endian and get the kernel > > > > to switch to big endian once booted. The image header should always be > > > > little endian. > > > > > > That would be fun. :) You'd also have to switch back and forth to make > > > EFI runtime services calls. > > > > OK, we'll have to live with this restriction. > > Or just disable runtime services on the switch to big ending. Big endian > should not disable the stub (but getting it to work could be a follow-up > patch) > The other problem with BE is that the PE/COFF masquerading is built into head.S so the same Image can be used for EFI and non-EFI. I don't see a BE opcode which we could us to provide the magic "MZ" at the start of a BE kernel Image. --Mark -- 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
