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Message-ID: <eb77b42f8ec4b67c1554dfac4a8efdfd8a4168c6.camel@xry111.site>
Subject: Re: [PATCH 1/1] LoongArch: Fixed loongarch kernel csr_xxx implicit
 declaration.
From:   Xi Ruoyao <xry111@xry111.site>
To:     =?gb2312?Q?=C0=EE=D3=EE=C5=F4?= <liyupeng@zbhlos.com>
Cc:     chenhuacai <chenhuacai@kernel.org>, kernel <kernel@xen0n.name>,
        "jiaxun.yang" <jiaxun.yang@flygoat.com>,
        loongarch <loongarch@lists.linux.dev>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        caizp2008 <caizp2008@163.com>
Date:   Wed, 31 Aug 2022 19:09:47 +0800
In-Reply-To: <AGcAvgDYFKf5CnvlznsCy4ok.3.1661932466929.Hmail.liyupeng@zbhlos.com>
References: <feb773a8df5d30b8d9347d1c922997c9da1fd06a.camel@xry111.site>
         <AGcAvgDYFKf5CnvlznsCy4ok.3.1661932466929.Hmail.liyupeng@zbhlos.com>
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On Wed, 2022-08-31 at 15:54 +0800, =E6=9D=8E=E5=AE=87=E9=B9=8F wrote:
>=20
> thank you for your reply=E3=80=82
> I used the latest gcc tool on the official website of loongson,gcc-
> 8.3.0.
> http://www.loongnix.cn/zh/toolchain/GNU/

Vanilla kernel cannot work with Loongnix:

1. In Loongnix, GRUB loads pass the essential information to the kernel
following "Loongson Firmware-Kernel Interface Specification".  Vanilla
kernel does not support it and will never support it.
2. In Loongnix, the syscall numbers are different and the layout of some
data structures used in kernel UAPI is different.  Any Loongnix
application invoking a syscall will likely blow up immediately on a
vanilla kernel.

These two problems are very difficult.  There is some plan to insert
compatibility layers to work around them, but not even one line of code
has been written AFAIK.

So if you want to build a kernel for Loongnix, don't use the vanilla
kernel.  If you just want to build a vanilla kernel with a pre-built
cross toolchain, use the toolchain from
https://kernel.org/pub/tools/crosstool/.
--=20
Xi Ruoyao <xry111@xry111.site>
School of Aerospace Science and Technology, Xidian University