On Thu, 2013-01-10 at 18:04 +0000, David Woodhouse wrote: > From: David Woodhouse <[email protected]> > > If the bootloader calls the EFI handover entry point as a standard function > call, then it'll have a return address on the stack. We need to pop that > before calling efi_main(), or the arguments will all be out of position on > the stack. > > Signed-off-by: David Woodhouse <[email protected]> > --- > arch/x86/boot/compressed/head_32.S | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/x86/boot/compressed/head_32.S > b/arch/x86/boot/compressed/head_32.S > index aa4aaf1..ccb2f4a 100644 > --- a/arch/x86/boot/compressed/head_32.S > +++ b/arch/x86/boot/compressed/head_32.S > @@ -50,8 +50,10 @@ ENTRY(startup_32) > pushl %eax > pushl %esi > pushl %ecx > + sub $0x4, %esp > > .org 0x30,0x90 > + add $0x4, %esp > call efi_main > cmpl $0, %eax > movl %eax, %esi
It's worth pointing out that efilinux doesn't invoke the handover protocol as a function, it pushes arguments onto the stack and jumps. So this change will actually break that boot loader. Is there a particular reason why you need to invoke it as a standard function on 32-bits? -- Matt Fleming, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
