[M] Change in coreboot[main]: libpayload/x86: Extend exception handling to x86_64 architecture

[Subrata Banik (Code Review)]

Attention is currently required from: Arthur Heymans, Julius Werner, Paul Menzel.

Subrata Banik has posted comments on this change by Subrata Banik. ( https://review.coreboot.org/c/coreboot/+/83036?usp=email )

Change subject: libpayload/x86: Extend exception handling to x86_64 architecture
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Patch Set 16:

(1 comment)

File payloads/libpayload/arch/x86/exception_asm_64.S:

https://review.coreboot.org/c/coreboot/+/83036/comment/505c34e5_50a44602?usp... :
PS13, Line 338: offset
> > > > offset 32:63 goes into 8(%rax)
> > >
> > > actually we have marked that zero already https://review.coreboot.org/c/coreboot/+/83036/13/payloads/libpayload/arch/x... here, hence, unable to comment here.
> > >
> > > let me add the comment above?
> > >
> > > WDYT?
> >
> > 0 is wrong if you link this payload above 4G. Maybe it's easier
>
> Unable to get into the exception handle if we have some non-zero value at offset 32-64 of IDT table.
>   +    movl %edi, 8(%rax)

do you think https://review.coreboot.org/c/coreboot/+/83036/16/payloads/libpayload/arch/x... its because of x86_64 Canonical Form ?