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Browsing Posts published in April, 2006

Windows on Macs

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Posted by hmafra:

What do you think of Robert E. Cringely on the future of Boot Camp, Windows Vista and Macintoshes?

he idea makes sense, but, would it be feasible?


Rainer Brockerhoff wrote:

…Indeed, the usual hardware developer notes which used to come out a few weeks after a new PowerPC Mac was released are still absent for all Intel Macs – not that these notes ever went into chip-level detail of any Apple hardware.

The developer note for the Intel iMacs just came out (along with a few others). There are some interesting tidbits – for instance, EFI Flash memory size is 2 megabytes – but no mention of the TPM chip, as expected. Also, all the recent notes are very terse and go into less detail, even for PowerPC machines…

Rainer Brockerhoff wrote:

…But the main advantage is that the OSes for the virtual machines can be simplified. All the tricky little kexts and drivers you see on current PowerPC Macs will be substituted by one or two “generic” versions which will interface to the virtual peripherals simulated by the hypervisor, and the actual machine’s peripheral drivers will be in EFI or on the cards themselves.

One variation of this idea would be for Apple to sit down with game developers and define a basic Intel VM; just enough to see a drive partition, input devices and the video card. This would make porting very easy, as most games try to take over as much of the machine as possible anyway, and you’d have optimum performance.

camilotelles wrote:


Thanks, Camilo, I was about to link to that myself…

Posted by camilotelles:

Well, people sure have short memories.

I’ve commented several times before (for instance, here [8 months ago!], here, here, or here), that Apple’s Intel Macs contain an Infineon TPM chip. This from the very first developer transition kit, up to the latest released machine.

See my first link for details, and John Gruber‘s excellent analysis.

Today I was surprised to find several indignant articles pointing out that:

It looks like Intel has embedded “Trusted Computing” DRM protection in its Infineon chip and forgot to tell people.


…nobody wants to admit that the Intel Macs currently on sale have a TPM chip.

This is not only old news, but has been extensively photographed and discussed. It’s well-known that Apple uses the TPM chip in increasing degree in Mac OS X 10.4.x, to prevent people installing it on generic PCs, and it’s certain that Mac OS X 10.5 will also do so.

Does Apple come right out and say so? Admittedly not. Indeed, the usual hardware developer notes which used to come out a few weeks after a new PowerPC Mac was released are still absent for all Intel Macs – not that these notes ever went into chip-level detail of any Apple hardware. At the same time, Apple withdrew publication of a few kernel source files for Darwin, the open-source base for Mac OS X. Both facts demonstrate that Apple’s security locks are still in flux and may change extensively in the near future. Will all these things be documented in the future? Hard to say. If the TPM chip’s encryption is sufficiently strong, they could be documented without defeating Apple’s purpose; but keeping details hidden always helps.

Is this evil? Well, depends on your definition of course. As Gruber points out, people who are incensed about this should also boycott Linux for its support of several TPM chips, including Infineon’s. Certainly, Apple has a right to enforce its current license terms which state that Mac OS X should run only on Apple hardware.

But what else will the chip be used for in the future? As I’ve repeatedly wrote here before, using it for DRM protection of media – which is what most of the critics claim to fear – isn’t likely. Mostly because, if you do the math, Intel Macs will be a minority for years and any such protected media would either not work at all or be open on PowerPC Macs, of which there are several tens of millions still in operation.

What’s far more likely – and we’ll know for sure in August – is that the TPM chip will be used to boot a trusted hypervisor at the EFI level. Apple has even patented a scheme to run tamper-resistant code and more than one OS at once. From the wording it’s obvious that the TPM chip is used for that:

In one embodiment the system comprises a processor and a memory unit coupled with the processor. In the system, the memory unit includes a translator unit to translate at runtime blocks of a first object code program into a blocks of a second object code program, wherein the blocks of the second object code program are to be obfuscated as a result of the translation, and wherein the blocks of the second object code program include system calls. The memory unit also includes a runtime support unit to provide service for some of the system calls, wherein the runtime support unit is to deny service for others of the system calls, and wherein service is denied based on a tamper resistance policy.

So, what I think likely is that the machine will boot into the trusted hypervisor. This will be encrypted into firmware and decrypted, and checked against tampering, by the TPM chip. Once this is running it will show a screen like the Boot Camp boot selector, with one important difference: you’ll be able to select more than one OS to boot up. All of them, including Mac OS X itself, will run inside a virtual machine.

What’s the advantage? Of course all OSes will run at near-native speeds if nothing else is running at the same time – the hypervisor’s overhead will be negligible. In fact, this scheme has been used and refined on mainframes for decades, where it is assisted by hardware; now that Intel’s Core processors have hardware virtualization support, it should be easy to do likewise.

But the main advantage is that the OSes for the virtual machines can be simplified. All the tricky little kexts and drivers you see on current PowerPC Macs will be substituted by one or two “generic” versions which will interface to the virtual peripherals simulated by the hypervisor, and the actual machine’s peripheral drivers will be in EFI or on the cards themselves. This reduces disk and RAM usage at the expense of performance, although this shouldn’t be a problem except for games – but then, as I said below, hardcore gamers will prefer to boot directly into “the most popular game loader” anyway.

Another extremely desirable gain for Apple will be that they’ll only have a version of Intel Mac OS X that runs on this trusted virtual machine. To get this running on a generic PC, people would have to reimplement the entire Apple hypervisor too, write drivers etc., and even this would be easily defeatable by the TPM chip. Still, it’s a major architectural change and for that reason we’ll only see this in Leopard.

What boots it?

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OK, people have asked me to comment on Boot Camp Public Beta.

If you’ve been away for the last few weeks, the $13K+ prize to make Windows XP boot on an Intel Mac has been won by two puzzle addicts. Granted that their solution is complex to implement and runs slowly due to the lack of proper video drivers (and others), but it’s still impressive. My Intel Mac mini hasn’t arrived yet, so I can’t speak from firsthand experience, but it seems it overlays just enough legacy BIOS responses on the Mac’s EFI to interact with an complementarily modified Windows XP.

Well, Wil Shipley and others donated money to that effort, and this seems to have convinced Apple, about a week later, to make “Boot Camp” public. It consists of three parts: a firmware upgrade that puts the (optional) legacy BIOS support module into the firmware, a small utility that allows nondestructive repartitioning of an Intel Mac’s hard drive, and a CD containing XP drivers for most (though not all) Intel Mac peripherals. It’s a beta, and some things don’t work yet, but it’s much smoother than the hacked-together version. In effect, the Intel Macs can now be dual-booted with Windows XP; also, people report progress in booting some Linux variants, and Vista support may not be impossible anymore. Ah yes, Apple has also stated that something like this will be a part of Leopard aka Mac OS X 10.5, which will be demoed at the upcoming WWDC and may be out around the end of the year. And AAPL stock shot up nearly 10% over the next two days…

So much for the facts. Interpretations are diverse; in fact, I haven’t seen so many divergent comments since Intel Macs were announced last June.

As usual, after a couple of days, Gruber, Siracusa and a few others posted excellent analyses of the situation. However, much of the immediate commentary was – let’s charitably say – weird. Immediate doom has been predicted for Apple first and foremost, as well as for Microsoft, for Dell, and for software developers. Let’s look at that last idea first.

Most non-developers are saying that, obviously, Mac developers will now fold up and die, or migrate to become Windows developers in droves, or (if they support both platforms) discontinue Mac versions of their products. After all, all Mac support questions can now be answered by “boot into XP”. And Windows is where the money is, right?

Wrong. Let’s check each type of developer separately. There are the two big ones: Microsoft and Adobe. Microsoft obviously won’t close the Macintosh Business Unit (MBU); I hear it’s their top division in terms of income per employee. Obviously, most Mac users want Mac versions of their applications, even if they have to be from Microsoft. The same goes for Adobe products; most of them were, originally, ported from the Mac to Windows anyway. And even if Adobe is having a hard time porting their stuff from CodeWarrior to Xcode, eventually they’ll do so.

At the other end of the spectrum are small developers like myself, up to small 3- or 5-person shops. Very few of those are multiplatform. I can safely say that an overwhelming percentage are Mac-only because developing on the Mac, for the Mac, is enjoyable and lucrative. Read Wil Shipley’s interview and his WWDC Student Talk and see what I mean. Here’s a pertinent part:

I love the Mac user base because they tend to be people who are into trying out new software and recommending it to each other and giving the little guy a chance. Windows users have demonstrated, ipso facto, that they do not believe in the little guy.

The two types of Windows users I’ve identified at my café are:

a) I use Windows to run Word and Excel and browse the web (and read e-mail in my web browser), and

b) I’m a programmer and I spend all my time in a Windows IDE or hacking around with my system.

The problem is that market (a) already has all the software they think they’ll ever need, and clearly isn’t into looking beyond what they already have or they’d have noticed they could do all that they currently do, and more, but much easier, on a Mac. And market (b) is too small for me to aim any software at it.

No doubt most non-developers (and Windows developers like (b) above) believe that developers mostly hate their jobs and just do whatever distasteful thing is necessary to maximize their income. Well, it’s not really that way; granted that many of us have to work to pay for the groceries, and Mac-related jobs are not really plentiful (yet!), but many .NET slaves spend extra hours at their home Macs to write really cool software.

In other words, we write for the Mac because it’s satisfying and would do it even for free, all day, every day (assuming the grocery problem to be solved somehow). Would I migrate XRay to Windows? No way. The tools aren’t there, the APIs are uncool, and the Windows community – well, as far as I can tell, there’s no Windows community at all. And regarding the market size, better a small fish in a small pond, and all that.

So what about the middle-sized software companies? Here the situation may not be as clearcut. It depends a lot on company culture, I suppose. Are the people in charge active Mac users but also target Windows just because, well, they might sell a lot of copies over there? Or are they primarily Windows developers which also have a Mac version championed by a couple of vocal believers among their programmers? It could be either way, and only time will tell. But should some of the latter type close out their Mac support, they might have done it anyway sooner or later.

Now, game developers are a special case. Discounting for the moment some diehard Mac-only game developers, reactions among the multiplatform gamers have been very cautious. After all, a game user is the person most likely to dual-boot into Windows just to run the very latest game at full speed – though such a fanatic is still more likely to have a dedicated, souped-up PC just for that purpose. So, widespread availability of Boot Camp might, really, lead some game companies to neglect Mac versions, purely for economical reasons.

Update: Ouch, I forgot to put in John C. Randolph’s comment on this:

Apple now lets you use the most popular game loader!

…and he’s sooo right! icon_biggrin.gif

Stay tuned for more comments on this…

OK, April 1st

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Here’s a roundup

…see also Top 100 April Fool’s Day Hoaxes. Personally, I think the BBC’s Spaghetti Harvest is unbeatable.

Update: Chuq von Rospach reveals the truth about the RDF.

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