Archive for August 13th, 2007

Gentoo/MIPS on QEMU: Update

Monday, August 13th, 2007

Well, those who recall my earlier post… I’ve managed to get a VM going.
qemu-mipsel ~ # emerge --info
Portage 2.1.2-r9 (default-linux/mips/2007.0/cobalt/o32, gcc-4.1.1, glibc-2.3.6-r4, 2.6.18-4-qemu mips)
=================================================================
System uname: 2.6.18-4-qemu mips MIPS 4Kc V0.0 FPU V1.0
Gentoo Base System release 1.12.6
Timestamp of tree: Sun, 12 Aug 2007 13:50:01 +0000
dev-lang/python: 2.4.3-r1
dev-python/pycrypto: 2.0.1-r5
sys-apps/sandbox: 1.2.17
sys-devel/autoconf: 2.61
sys-devel/automake: 1.6.3, 1.9.6-r2, 1.10
sys-devel/binutils: 2.16.1-r3
sys-devel/gcc-config: 1.3.14
sys-devel/libtool: 1.5.22
virtual/os-headers: 2.6.14.4
ACCEPT_KEYWORDS="mips"
AUTOCLEAN="yes"
CBUILD="mipsel-unknown-linux-gnu"
CFLAGS="-mips1 -O2 -pipe"
CHOST="mipsel-unknown-linux-gnu"
[...]

The assessment? Well, firstly, it’s slow, very slow. I realise the BogoMIPS is a somewhat dubious benchmark… but:

QEMU:
system type : Qemu
processor : 0
cpu model : MIPS 4Kc V0.0 FPU V1.0
BogoMIPS : 246.27

versus… my Qube2 (250MHz):
system type : Cobalt Qube2
processor : 0
cpu model : Nevada V10.0 FPU V10.0
BogoMIPS : 248.83

one of the Lemote Fulong miniPCs (660MHz):
system type : lemote-fulong
processor : 0
cpu model : ICT Loongson-2 V0.2 FPU V0.1
BogoMIPS : 444.41

or my IP28 (195MHz):
system type : SGI Indigo2
processor : 0
cpu model : R10000 V2.5 FPU V0.0
BogoMIPS : 193.53

Is it usable?  Well, if that benchmark is anything to go by, it isn’t that much slower than my Qube2.  But the CPU that QEMU emulates, doesn’t implement any cacheops… so in that respect, it’s even slower than the Qube2 (which at least has some primary cache) .  I’ll know as I install more stuff, but my first impresions are that it’ll be too slow for most tasks running Gentoo, unless your host PC is a beast (mine isn’t).  Unless you’re doing development, you’d be better off just running everything on the host PC bypassing the emulation layer.

I might consider putting together a kernel that will allow installation of Gentoo/MIPS, since it’ll be a good way for me to test the userland components of any netboot images I produce.  I’m yet to try a kernel build, at the moment I’m using Debian’s kernel.

It is doubtful that this machine will ever be officially supported, but I’ll consider it if there’s sufficient demand. ;-)

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