Hi Thorsten, Le jeudi 06 décembre 2012 à 20:56 +0000, Thorsten Glaser a écrit : > Laurent Vivier dixit: > > >I think it should be a good idea to play with the linux-user mode of > >qemu. > > Does that emulate an MMU? The system mode doesn’t, IIRC.
MMU is useless in usermode emulation. > >qemu linux-user mode traps guest (m68k) syscalls to translate them to > >native ones. It's not perfect. > > Well right. It also doesn’t catch genuine kernel bugs, and > probably a lot less other bugs (I remember having FPU issues > which turned out to be ARAnyM bugs, but still). indeed > > >really usable for a debian buildd, but it can be used to develop and > > Hum, but right now, all we need is buildds. I agree > >correct build issues. For instance, you can build glibc, kernel and gcc > >concurrently on one machine in less than a day ;-) > > I’m down to about 1.5 days on gcc. With your bogomips from below, > I believe you can’t get any faster, unless you go parallel building, > which won’t work because, right now, m68k is not SMP. A full system simulator is slow mainly because of I/O. User-mode emulation has native I/O performance. > (I also don’t think it gets the new cmpxchg syscall right ;) > > >I have tested it on an ubuntu 12.10 x86_64 system, and it seems to work > > Urgh… I’d not trust *buntu to get anything right… > > >Note3: and for those that want to know the real power of their new m68k > >machine, I've added in attachement bogomips.c to compute the bogomips > >and the equivalent 040 cpu frequency. Mine (on a Q6600 a 2.4 Ghz) is: > >$ ./bogomips > >Clocking: 132 > >BogoMips: 104.00 > >Calibration: 524288 > > I get this on ARAnyM, on a 3.2 GHz host box: > > Clocking: 265.269 > BogoMips: 209.00 > Calibration: 1048576 > > So I believe it’s not slower ;-) but more reliable. On a full system emulation, like ARAnyM or even KVM, clock (needed to compute instructions per second) is not reliable. So you can't compare ... > But still, thanks. I guess your method makes for a quicker start, > although I believe that, for most people, Aranym/Quick from the > Debian wiki would be enough (and possibly, as you already said > it’s not complete, needed) to work on build issues. > > (Actually, the general consensus is that we need *less* emulation > and more bare iron right now.) As I said, it is just to play or to help to solve build issue and saving time. Don't play, don't have fun ;-) Regards, Laurent -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: http://lists.debian.org/1354832087.7874.12.camel@Quad
