From: adventures in9 <email@example.com>
To: 9fans <firstname.lastname@example.org>
Subject: Re: [9fans] spim syscall stack adjustment
Date: Fri, 27 Jan 2023 13:10:32 -0800 [thread overview]
Message-ID: <CAPfmpJB0jLgyAc6L6vNC32-Uh1LCfxOe1eCKRW9tr0ORsK32wg@mail.gmail.com> (raw)
I could try and build a spim world without the ADD in syscall to see
what happens. It might be a week or 2 before I can find the time.
As for why it does it. I never really looked into it. I figured it
was just another endian issue. I had enough bugs that when I got past
that one I just moved on to the next. But I do need to set up a fresh
9 Front install to go through and get patches for all the mips and
I also have a big-endian Atheros/Qualcomm chip that I need to get
around to building a kernel for, and then there will be a close to 1
to 1 chip to compare mips and spim stuff.
On Thu, Jan 26, 2023 at 6:47 PM Anthony Martin <email@example.com> wrote:
> Does anyone know why the libc system call functions for
> spim add four to the stack pointer (R29) before issuing
> the SYSCALL instruction?
> It was introduced in the third edition but there were
> never any spim kernels released so I wasn't able to
> compare the libc additions to the trap code.
> I was watching one of adventuresin9's videos about his
> ongoing port to the MediaTek MT7688 and he mentioned
> having to modify the stack offsets in the syscall trap
> handler just as cherry9 had done for the loongson port.
> Is there any reason not to simply get rid of that ADD $4?
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prev parent reply other threads:[~2023-01-27 21:11 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-27 2:46 Anthony Martin
2023-01-27 21:10 ` adventures in9 [this message]
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