Re: [edk2-devel] [edk2-test PATCH v1 2/2] SctPkg: Enable RISCV64 support using AARCH64 sources

["Leif Lindholm" <leif@nuviainc.com>]

On Tue, Feb 09, 2021 at 14:47:46 +0100, Heinrich Schuchardt wrote:
> >>> I have no idea why the alignment would be 3 on other platforms, so I
> >>> don't know how to fix it.
> >>> If anyone knows more, please let me know. I'll just change the comment
> >>> to say Riscv64.
> >>>
> >>>>> +.align 3
> >>
> >> Both on Aarch64 and on RISC-V an odd alignment value makes no sense.
> >>
> >> .align 8 should do no harm. But is it needed?
> >
> > The glory of the GAS .align directive is that its meaning differs
> > between architectures and executable formats. On ARM/AArch64, as well
> > as on RISC-V (I think?) the alignment is described as a power of 2.
> >
> > So .align 3 on ARM and others are the same as .align 8 on x86 (ELF)
> > and others.
> >
> > (It might not be a bad idea to start replacing .align directives with
> > .baligh to reduce confusion.)
> 
> Thanks for pointing out the different meanings of .align. They are
> documented in binutils-2.36/gas/doc/as.info chapter 7.3.
> 
> .balign is GNU assembler specific.
> 
> Do we have to consider other assemblers here?

I don't think so.
The GNU family of toolchains are the only ones using .s/.S sources.
Unless there are GNU-compatible assemblers that don't support the
directive.

Visual Studio uses .asm on ARM* and .nasm on x86.

/
    Leif