qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v2 21/30] Deprecate 32 bit big-endian MIPS


From: Pierre Muller
Subject: Re: [PATCH v2 21/30] Deprecate 32 bit big-endian MIPS
Date: Fri, 16 Sep 2022 12:10:30 +0200
User-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2



Le 16/09/2022 à 10:38, Richard Henderson a écrit :
On 9/16/22 10:08, Pierre Muller wrote:

    I am using gcc230 machine for the gcc compile farm.

    This is a big endian mips64 machine runnig Debian Buster.

When compiling the qemu 7.1.0 release source,
the generated binaries are 32-bit mips binaries,
and I did not find out how to generate a 64-bit versions
of the executables.

Yes, that host seems to have been installed with the o32 abi instead of the n64 
(or n32) abi.

Indeed,
    As mips32 seems to still be the default arch that gcc uses,
I don't really understand the idea of depreciating big endian mips32.

Is this solely related to cross-compilation issues?

Yes.  Even gcc230 is fairly small for actually compiling qemu, it takes many 
hours.  So
for many hosts we rely on cross-compilation from x86_64.

For that, we rely on the set of cross-compilers built by Debian 11 (bullseye) 
plus (!) the
host libraries for that platform.  We cannot simply rely on 
crossbuild-essential-mips
because building qemu requires many more system libraries than just libc.

In https://www.debian.org/releases/bullseye/, you'll note that big-endian mips 
is not
listed, so we are now missing those system libraries.

 So this is not limited to mips32, as big endian mips64 is also not supported 
anymore in bulleye...

We are not intending to *remove* support for big-endian mips, as 99% of the 
code paths are
shared with little-endian mips, which we can continue to test.  But we are now 
saying that
big-endian mips is not "supported" and might break.

  Thank you for your answer and the clarifications!

Pierre



reply via email to

[Prev in Thread] Current Thread [Next in Thread]