From mboxrd@z Thu Jan  1 00:00:00 1970
Subject: Re: 32bit compat mode for arm64
References: <CAFLxGvyr7f8bUxaEVpEwSGYEvX4FrkpGBV6qa2sR3SHq3wi_Yw@mail.gmail.com>
From: Jan Kiszka <jan.kiszka@siemens.com>
Message-ID: <40a67d93-847a-d67f-bbc7-a6494591e97e@siemens.com>
Date: Mon, 2 Mar 2020 13:16:50 +0100
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To: Richard Weinberger <richard.weinberger@gmail.com>, xenomai@xenomai.org

On 28.02.20 22:01, Richard Weinberger via Xenomai wrote:
> Hi!
> 
> I noticed that running 32bit arm EABI xenomai userspace is currently
> not possible
> on arm64 kernels.
> 
>  From a quick look I see the following tasks to make it happen:
> - syscall gate adaptations for cobalt arm32 syscalls (they are
> different from regular arm EABI)
> - teach ipipe_root_nr_syscalls() on arm64 about __NR_compat_syscalls
> - Don't use XENOMAI_ABI_REV for compat userspace on arm64
> - Implement a syscall32-table.h (for COBALT_SYSCALL32emu_DECL() and friends)
> 
> Is this something which will be supported sooner or later?
> ...or is there a massive show-stopper I didn't notice so far?
> 

Well, if there is a strong use case, usually proprietary legacy software 
that refuses to be ported to 64-bit, I would not refuse such a contribution.

Jan

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