Re: Preliminary results - was: Re: Question on BIGGEST_ALIGNMENT in GCC on NetBSD/m68k

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Eero,

On Mon, 23 Jun 2025 at 00:13, Eero Tamminen <oak@helsinkinet.fi> wrote:
> On 16.6.2025 18.39, John Paul Adrian Glaubitz wrote:
> > To summarize:
> >
> > - the ELF header provides provides the e_ident and e_flags fields which could be
> >    used for identifying a Linux/m68k system using the 4 bytes alignment ABI
> > - MIPS uses e_flags for differentiating its ABIs
> > - PA-RISC sets e_ident to 0x03 (Linux) while every other arch uses 0x00 (SysV ABI)
> > - qemu-user needs to be patched to deal with the changed alignment (include/user/abitypes.h)
> > - the kernel needs to be patched to deal with the changed alignment (arch/m68k/kernel/signal.c)
> > - NetBSD uses an emulation layer which allows 2 bytes alignment a.out executables on an
> >    ELF system with 4 bytes alignment
>
> So Linux could eventually have similar emulation layer for 2-byte
> aligned ELF binaries (I don't see point in a.out support)?

Support for a.out was removed from Linux in commits 19e8b701e258701b
("a.out: Stop building a.out/osf1 support on alpha and m68k") in v5.18
and 987f20a9dcce3989 ("a.out: Remove the a.out implementation") in v6.1.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds