Ports LoongArch

[dbhrscom]

Hello！

About LoongArch Brief introduction

LoongArch is the RISC instruction set launched by loongson in 2021. The details are as follows:

LoongArch Reference Manual

​

It works on the loongsong 3a5000 processor.

I have two computers with this processors，Prepare to do some basic ports on FreeBSD

So I want to consult

Have you considered or started porting loongarch to BSD system?

And what exactly I need to do.

Thanks!!!

 

[oOiOo]

Hello,
To my knowledge, Loongsong architecture is based on MIPS. Unfortunately, even though MIPS is present in FreeBSD 13's source code , it's support has been removed on 2022/01/01 . Howether, NetBSD support Loongsong devices : http://wiki.netbsd.org/ports/evbmips/loongson/.
Regards

 

[Lamia]

Like ARMv7 (Cortex A8) became unsupported from FBSD 12.2.

 

[dbhrscom]

Hello,
To my knowledge, Loongsong architecture is based on MIPS. Unfortunately, even though MIPS is present in FreeBSD 13's source code , it's support has been removed on 2022/01/01 . Howether, NetBSD support Loongsong devices : http://wiki.netbsd.org/ports/evbmips/loongson/.
Regards

In 2021, the 3a5000 processor released by Godson no longer uses the MIPS instruction set, but uses LoongArch, a new instruction set.

 

[Crivens]

In that case we are talking about a complete new port. Step #1 would be llvm support. Is that done?

 

[covacat]

The ISA has been referred to as "a fork of MIPS64r6" due to a perceived lack of changes judging from instruction listings.[30][31] In August 2021, Linux maintainers complained that submitted LoongArch code is "...a blind copy of the MIPS code...", however "only with a different name".[32]

 

[dbhrscom]

LoongArch is a RISC instruction set, which can be used for reference. However, when running Linux, LoongArch and MIPs are not compatible.

 

[dbhrscom]

In that case we are talking about a complete new port. Step #1 would be llvm support. Is that done?

Please refer to

https://github.com/llvm/llvm-project/commits?author=SixWeining

GitHub - loongson/llvm-project: The support for loongarch in this repository has been refactored and merged into the upstream repository of LLVM, so its mission is completed and it will be deleted soon. Please use the upstream repository directly in

The support for loongarch in this repository has been refactored and merged into the upstream repository of LLVM, so its mission is completed and it will be deleted soon. Please use the upstream re...

github.com

 

[eexx]

In that case we are talking about a complete new port. Step #1 would be llvm support. Is that done?

Done in llvm 16.0.0
https://releases.llvm.org/16.0.0/docs/ReleaseNotes.html#changes-to-the-loongarch-backend

 

[Crivens]

Great. Now we need hardware and volunteers. Any takers?

 

[kpedersen]

With regards to donating hardware; my Chinese is a bit rusty, but I am fairly sure that their website clearly states:

Good bloomin luck getting hold of one of these chips. We have made them as difficult to source as those fancy Loongson Lemote laptops released in 2006.

(translation mine).

 

[Crivens]

I had checked at that time, and they were like mirages. And too little bang for too many bucks.

 

[astyle]

If hardware is hard to get ahold of, it will take a LOONG time to get the software working