Darwin 1.4.1 installs on Qemu 2.7!

Darwin 1.4.1 on Qemu

Darwin 1.4.1 on Qemu

I tried the x86 version from Apple’s Darwin web site.  For those who don’t know Darwin was (is?) an open source version of the OS X kernel and userland.  This was on parity with the OS X 10.1 release.  It was notoriously picky about hardware back in 2001, let alone anything today, and much to my amazement it installed fine on Qemu 2.7.

Source code to the packages should be about here.

Whlie I may have a kernel dump of Darwin 0.3, old releases appear next to impossible to find.

I just played with NeXTSTEP 0.8

NeXTSTEP 0.8

NeXTSTEP 0.8

And I have to say, it’s pretty impressive!  Previous flies on my system, having owned a cube, I can say that the 68030 on this is WAY faster.  And I’ve always read about 0.8, and kind of figured it was basically lost to the winds of time.  It’s really cool to see it boot up!  And the emulated disks are so much faster than the magnetic optical drives of the day.

It’s amazing to think that in 1988, the current world of iThings had just started.

I was looking back at old posts

And I saw my old look at Mach+Lites.  And of course there was a qcow disk image associated with some ancient version of Qemu which I can’t run on Wine on OS X.  So I figured with a bit of fun I’d update the disk image to work with Qemu 1.7.0.

Luckily Qemu 0.15.1 works just fine for it’s qemu-img.  So a quick

qemu-img convert -f qcow -O vmdk mach.img mach.vmdk

and I had my image.  I’m not sure of what the NE2000 parameters that Mach can use to enable the network, but I do recall it was easier to just rebuild Qemu around them.  However this time, I switched to the Mach kernel that utilized Linux device drivers to get a working network.

I updated the hard disk file here.

Screen Shot 2013-12-27 at 12.16.18 AM

For the two or three people who care about BSD evolutionary dead ends.

A tale of two kernels.

Back in the early 1990’s Microkernel’s were all the rage. Everywhere you would go you’d hear all about Pink, Taligent, Windows NT, and the grand daddy of them all Mach.

Probably the most well known debate about microkernel vs monolithic kernels was the Tanenbaum vs Torvalds debate that raged on comp.os.minix back in 1992. You can read the entire thing here : ( http://www.oreilly.com/catalog/opensources/book/appa.html ). It was interesting in the sense that even Ken Thompson of UNIX fame even chipped in. Tanenbaums’s major points were that a microkernel is more inherently portable than a monolithic kernel, and that microkernels could be more reliable, and easier to maintain. Of course more than 10 years later we can see that Linux still flourishes, and that outside of Windows NT & OS X no mainstream OS relies on a microkernel. Even OS X treats mach more as a call library than a traditional microkernel, since all of the exe’s in Darwin / OS X are Mach-O format, not COFF/ELF,A.OUT, etc etc.

Mach started out as a project from CMU derived from the UNIX source code, to try to re-invent the lower levels of UNIX into something that would scale easier to multiprocessors, support for threads, and the holy grail of them all, expand it’s portability. Sadly the first few versions of Mach are barred from distribution due to their inclusion of encumbered UNIX source code. However when the university of Utah picked up Mach, and released Mach4 (UK22, info here http://www.cs.utah.edu/flux/mach4/html/Mach4-proj.html ), including full source. Also they provided Lites, a BSD server that can run atop Mach, giving the user a ‘UNIX’ system, as it were.

Lites

Lites

So digging through some network groups, and testing stuff, I finally slapped together the pieces, and built a Mach/Lites system on NetBSD 1.1 . And how does it perform? It’s significantly slower than NetBSD is. You can tell that the amount of context switching involved in Mach as a program makes a call the microkernel, which in turn validates & passes it to the server, which further validates, runs the process, then sends the results back to the kernel, which then passes it back to the program. I’ve heard in a worse case scenario a 500% reduction in speed. You can always read more info on the fine wiki article here ( http://en.wikipedia.org/wiki/Mach_kernel ).

Lots of people will argue that microkernel’s have simply failed, and that it’s simply an example of what seemed like a good idea being pushed too hard once it was found to fail. It a lot of ways it reminds me of ADA.

So for now I’m going to provide a Qemu image of Lites running on Mach 4. unzipping the file will provide you with a lites.cmd file which for windows users you can just run directly. Things to note are:

-The version of Qemu that I’ve bound requires libpcap to be installed.
-Mach4 can only address 16mb of ram, due to DMA issues across the 16mb line.
-I’ve enabled user mode networking so that
-the cmd file sets up local port 23 to be redirected to the VM. This will allow you to telnet in simply by ‘telnet localhost’. You may want to use putty for better terminal handeling
-The included Gcc 2.4.5 is ancient. Outside of building a simple irc client, I wouldn’t expect much.
-The boot process is broken, and it’ll parse through the rc scripts twice. Just let it do it’s thing, and it’ll drop to a login prompt.

Logging into Lites/NetBSD

Logging into Lites/NetBSD

Other than that it behaves just like a NetBSD 1.1 machine.

Notice that grub boots the kernel /Mach.UK22 . When Mach boot’s it’ll load up the files emulator & startup. The ‘emulator’ is the Lites microkernel. Once it’s loaded it’ll start mach_init which just symlinks to /sbin/init and the normal NetBSD bootup will commence.

You can download my image directly here as MachUK22-lites-nat.zip.

Next time we’ll play with SLS Linux.