Date: Sun, 15 Feb 2026 07:56:21 -0800 From: Ahmad Khalifa <ahmadkhalifa570@gmail.com> To: Jessica Clarke <jrtc27@freebsd.org> Cc: "src-committers@freebsd.org" <src-committers@freebsd.org>, "dev-commits-src-all@freebsd.org" <dev-commits-src-all@freebsd.org>, "dev-commits-src-main@freebsd.org" <dev-commits-src-main@freebsd.org> Subject: Re: git: a60e7e6ff0ec - main - stand: compile ia32 EFI loader with -malign-double Message-ID: <CAMLT6uDpnYb%2B1DFCwYizOku%2Bpa4%2BAxGMa%2BFhJGztTjVpdyx9sw@mail.gmail.com> In-Reply-To: <CAMLT6uBpSKUH9Q6RRg65-jtW%2BoO3-TK0TeejqbVXxnrND2EQPQ@mail.gmail.com> References: <6991d07b.43f21.696cde4f@gitrepo.freebsd.org> <0B6A645E-D9E4-4337-B280-7E3CBA1FDC1B@freebsd.org> <CAMLT6uBpSKUH9Q6RRg65-jtW%2BoO3-TK0TeejqbVXxnrND2EQPQ@mail.gmail.com>
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On Sun Feb 15, 2026 at 4:27 PM +0200, Ahmad Khalifa wrote: > On Sun Feb 15, 2026 at 4:02 PM +0200, Jessica Clarke wrote: >> On 15 Feb 2026, at 13:56, Ahmad Khalifa <vexeduxr@FreeBSD.org> wrote: >>> >>> The branch main has been updated by vexeduxr: >>> >>> URL: https://cgit.FreeBSD.org/src/commit/?id=a60e7e6ff0ec1fdd66c2568ac6c03b843dbb3c9d >>> >>> commit a60e7e6ff0ec1fdd66c2568ac6c03b843dbb3c9d >>> Author: Ahmad Khalifa <vexeduxr@FreeBSD.org> >>> AuthorDate: 2026-02-15 12:23:26 +0000 >>> Commit: Ahmad Khalifa <vexeduxr@FreeBSD.org> >>> CommitDate: 2026-02-15 13:30:06 +0000 >>> >>> stand: compile ia32 EFI loader with -malign-double >>> >>> The UEFI spec says: >>>> Structures are aligned on boundaries equal to the largest internal >>>> datum of the structure and internal data are implicitly padded to >>>> achieve natural alignment. >>> >>> By default, structs containing members of type "long long" have 4 byte >>> alignment on i386. This caused some EFI structures to be subtly wrong. >>> >>> Fix this by compiling the ia32 EFI loader with -malign-double, which >>> bumps the alignment up to 8 if such members are present. >> >> This seems like a dangerously big hammer. Are there any types shared >> with libsa or the kernel itself that would change layout? (I suppose >> for the latter they already need to be aligned as the kernel is 64-bit?) > > For the kernel, any shared types would have already needed to be > aligned, yes. I didn't consider shared types with either libsa or libefi > though, I'll look into it now. Nice catch. > Okay, so libsa, libefi, liblua and ficl all share types with the loader. Quite obvious in hindsight... I'll back this out until I come up with something better. >> >> Annotating just the EFI types would seem more appropriate, like how we >> annotate function pointers to use the Microsoft calling convention. > > They're all under contrib unfortunately. Not sure if we want to > introduce that big of a diff with upstream. > >> >> Jessicahome | help
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