From: Greg Ungerer <gerg@kernel.org>
To: Rob Landley <rob@landley.net>, linux-m68k@vger.kernel.org
Subject: Re: m68k fdpic toolchain?
Date: Sun, 28 Jan 2024 22:55:19 +1000 [thread overview]
Message-ID: <5534a940-2346-4911-8395-aeefd3d50513@kernel.org> (raw)
In-Reply-To: <18232799-792d-e5c4-5483-00e84b8bd530@landley.net>
On 28/1/24 20:27, Rob Landley wrote:
> Now that we can build coldfire fdpic support in the kernel, does a _compiler_ exist?
No, no fdopic support has been added to bgcc for m68k/coldfire.
> https://lore.kernel.org/linux-mm/20220428033319.239341-1-gerg@linux-m68k.org/T/
>
> I built buildroot's mcf5208evb defconfig and booted it under qemu, but it's
> binflt, which I'm not adding to my test system's package dependencies. According
> to fs/Kconfig.binfmt:
>
> config BINFMT_ELF_FDPIC
> bool "Kernel support for FDPIC ELF binaries"
> default y if !BINFMT_ELF
> depends on ARM || ((M68K || RISCV || SUPERH || XTENSA) && !MMU)
>
> So I can select it, but in gcc's current git "grep -irl fdpic gcc/config" only
> has hits in the sh, arm, frv, and bfin directories.
As-is today you can load and run PIE ELF binaries using this support.
No additional changes to binutils or gcc required for that.
Regards
Greg
> Two of those three (frv and blackfin) were jettisoned by linux-kernel due to
> loss of expertise in the development community. I've already got an sh2 fdpic
> test system, but only on real hardware, not qemu (which decided to add
> qemu-system-sh4 instead of qemu-system-sh way back when, and thus never
> populated the rest of the family).
>
> I'm happy to use out-of-tree patches for m68k if that's what's available, but I
> haven't been able to find any. I assume that enabling fdpic means the ABI was
> documented specifying the registers for the extra segments...?
>
> Rob
>
next prev parent reply other threads:[~2024-01-28 12:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-28 10:27 m68k fdpic toolchain? Rob Landley
2024-01-28 12:55 ` Greg Ungerer [this message]
-- strict thread matches above, loose matches on Subject: below --
2024-01-27 23:40 Rob Landley
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