On Tue, Jan 14, 2014 at 6:44 AM, Mark Salter <msalter@xxxxxxxxxx> wrote: > On Mon, 2014-01-13 at 19:49 +0100, Arnd Bergmann wrote: >> On Friday 10 January 2014, 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. Support in the COFF header >> > for signed images was provided by Ard Biesheuvel. >> > >> > Signed-off-by: Mark Salter <msalter@xxxxxxxxxx> >> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> >> >> You got the ordering of the S-o-b lines wrong. Since you send the >> patch, your name should come last. > > Yes. > >> >> > +config EFI_STUB >> > + bool "EFI stub support" >> > + depends on !ARM64_64K_PAGES && OF >> > + select LIBFDT >> > + default y >> > + help >> > + This kernel feature allows an Image to be loaded directly >> > + by EFI firmware without the use of a bootloader. >> > + See Documentation/efi-stub.txt for more information. >> > + >> > endmenu >> >> Why not ARM64_64K_PAGES? I thought that it was going to be the >> default for a lot of distros that would need to run on UEFI systems. > > The UEFI spec currently mandates 4k page size. We may be able to work > around that or get the spec changed, but for now it is just 4k pages. > >> >> > menu "Userspace binary formats" >> > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile >> > index 5ba2fd4..1c52b84 100644 >> > --- a/arch/arm64/kernel/Makefile >> > +++ b/arch/arm64/kernel/Makefile >> > @@ -4,6 +4,8 @@ >> > >> > CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET) >> > AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) >> > +CFLAGS_efi-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) \ >> > + -I$(src)/../../../scripts/dtc/libfdt >> >> Hmm, this is pretty ugly. I notice the same has been done on MIPS >> as well, but I'd hope we can find a proper way to do it. > > Yes, I just copied that from mips. I can look into some more. > >> >> > diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c >> > new file mode 100644 >> > index 0000000..10d02bf >> > --- /dev/null >> > +++ b/arch/arm64/kernel/efi-stub.c >> > + >> > +/* Include shared EFI stub code */ >> > +#include "../../../drivers/firmware/efi/efi-stub-helper.c" >> > +#include "../../../drivers/firmware/efi/fdt.c" >> >> It gets worse here. > > Well, I'm open to suggestions here. The shared code has to work with > stubs which are built into kernel (arm64) and which are part of the > compressed image wrapper. > The decompression algorithms are shared among the compressed image wrappers using #include of C code, so this is following that convention. The only other mechanism that I saw for sharing code with the compressed image wrappers was copying of files, as is done with the FDT files for the ARM compressed wrapper. I agree that neither of these is elegant, but whatever we do needs to work for compiling into the decompression wrapper (arm) and the kernel proper (arm64). Roy -- 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
