Blue Screen of Death for Mac OS X

An anonymous reader writes "Possibly nothing in the OS world has as much of a bad rap as the infamous BSOD (blue screen of death) in Microsoft Windows. On the other hand Apple hides the ugly kernel panics behind a nice looking GUI which only tells you its time to restart your dead system. Interestingly Mac OS X kernel has a secret API which lets you decide what your kernel panics are going to look like! In this Mac OS X Internals article Amit Singh explains how to use this API. Apparently you can upload custom panic images into the kernel and there's even a way to test these images by causing a fake panic. The article also shows the ultimate joke is to upload an actual BSOD image for authentic Windows looking panics right inside of OS X."

Comments

Not like Microsoft invented it...

[ackthpt]

It's not like Microsoft invented it, either. I remember these quite unfondly. Before that I had a frozen screen on a C64. And before that I had stopped lights on the PDP-11 display. And before that we had random characters all over the screen of Ohio Scientific (OSI) computers.

But Microsoft is widely credited with perfecting the BSoD and giving it fame.

A system crash with a tasteful little box can be as easily dispised as all the the preceding. I suppose, like everything Apple is doing these days, they've given it a certain panache and now everybody will want one.

Re:Not like Microsoft invented it...

[DingerX]

Guru meditations were awesome, and I fondly remember that flashing red border.

But Amiga wasn't first. The Mac "Bomb" preceded it, and was notoriously useless for troubleshooting.

Still, most Windows XP users haven't seen a BSOD ever. Go ahead and ask them. See, Windows XP solved that. But mysteriously, their power supply is unreliable, and "trips" on the slightest whim.

You gotta love that. "BSOD is bad for marketing, and most people don't know what to do with the information anyway. Let's just reset the computer and pretend it's a power spike."

I'd advise people to change their default settings, but one time I had "write memory contents to log file on BSOD" enabled when I was moving data about, and hand less free memory on my HD than in RAM.

Don't ever, ever do that.

Re:Not like Microsoft invented it...

[MyDixieWrecked]

A system crash with a tasteful little box can be as easily dispised as all the the preceding.

that is precisely true.

My machine at work has some kind of hardware problem that was never quite solved while it was under applecare. it "panics" at least once a day, some days, it'll "panic" 5-10 times. Some things that set it off are scrolling in a terminal window (such as when I'm sync'ing portage on our server) or putting an audio CD in the lower optical drive.

The last time we brought it to tekserve, they claimed that both scsi drives were bad and they replaced them, and we didn't have a panic for a couple months, but by the time they came back (and with a vengence, I might add), there was no more applecare coverage...

I quote "panic" because sometimes I get that nice pretty "please restart your computer" screen, sometimes I get the text dump on the desktop, and sometimes the machine locks up, altogether.

luckily, we're getting one of those nice quad-xeon machines as soon as adobe releases the new creative suite, at which point I'll throw this machine out of a window.

Re:Not like Microsoft invented it...

[Anonymous Coward]

It's not like Microsoft invented it, either.

Microsoft had a single DEBUG line in the registry for Windows 95 -- it allowed the application of your choice to intercept the crash.

The first commercially successful program to implement it was "Power Utilities 95 with Crashproof" that handled/exposed many hardware conflict sins without just covering them up.

About 50K copies later and good shelf space at Frys/COMPUSA/BestBuy , Symantec took notice and put out their $29 Crashproofing program that didn't perform dozens of system checks or even unmask the cause of the crash.

If version 1.0 of that Norton floppy disk consisted of anything more than copying a 1 line registry change and a pointer to a bitmap, then it never showed in practice.

Re:Not like Microsoft invented it...

[Frequency Domain]

No, MS didn't invent it. They just perfected it. Remember when there was talk about adding a BSOD hotkey to the MS keyboard, so you wouldn't have to go through the hassle of running software to get it?

Re:Not like Microsoft invented it...

[kabloom]

But Amiga wasn't first. The Mac "Bomb" preceded it, and was notoriously useless for troubleshooting.

Error: Type 11

"But I keep typing 11 and nothing's happening"

Likewise

[Umbral Blot]

Likewise in windows you can change the background color and text color of the BSOD (or at least you could uder 98, I haven't had the desire to play around with it under 2000 / XP since they crash much less frequently).

Let me be the first to say

[GungaDan]

I, for one, welcome our new department-wide goatse.cx kernel panic message.

Any of you guys hiring?

Well on the upside

[OverlordQ]

The Win32 BSOD does give you better information so you can try to diagnose the problem.

Which is kinda lacking in the OSX Panic screen.

Re:Well on the upside

[RAMMS EIN]

But then MS made the brillant decision to reboot the system right when the BSOD appeared, robbing it of any usefulness. Or perhaps they didn't do it on purpose, but I've seen plenty of displays just go blue for a split second, then blank as the system started rebooting.

Re:Well on the upside

[mybecq]

The Win32 BSOD does give you better information so you can try to diagnose the problem.

Kind of like knowing that there were:
- 56 bulbs
- 24 horizontal grill bars
- 72 vertical ridges on 1600 sq ft of 1/4" steel
- 20% full gas tank
- 209,000 miles driven
- 3 tread patterns
- 5 axles
- 18 wheels

You still got hit by a truck.

Re:Well on the upside

[shawnce]

Kernel panic information gets logged on reboot to a file and you can capture a kernel core dump if you want.

Review... TN2063, TN2118, Debugging the Kernel, etc.

Re:Well on the upside

[kevmo]

I find it very useful for the rare occasions that I get BSODs anymore to at least know what driver caused the problem. If the BSOD lists something like atixxxxx, then I know that my video card screwed up, and so on. Because almost all of my crashes are caused by driver or hardware problems, its helpful knowing just what that problem is so I can fix the driver or replace the hardware (and thus almost never get crashes on that computer in the future).

The world's funniest joke

[Malc]

Hardly the ultimate joke. Jokes are supposed to be original. This has been a screen saver under Linux for years.

Anyway, couldn't this be described as the ultimate joke?

Old Hat

[overshoot]

Yawn.

Once upon a time, I was chairing an out-of-town meeting with a roomful of engineers. We spent most of the morning working a spreadsheet with margin calculations on it trying to come up with a margin budget that everyone could live with; I was running the machine that drove the projector.

The conversation took a turn away from the spreadsheet, and after a bit the BSOD came up onscreen. The panic in the room was palpable -- everyone figured we'd just lost the whole morning, and quite a few had afternoon flights out.

So I hit the shift key and entered my password to unlock the screen.

The classic BSOD screensaver gets the same amusement factor without the hassle of hacking OSX.

Leave it to apple!

[lostngone]

Leave it to Apple to give you a choice when it comes to Panic screens. Does Vista do this yet?

Keep it simple

[EmbeddedJanitor]

If you have an unstable system (BSOD-worthy), then it is probably best to rely on as few system resources as possible. THis includes GUIs etc. That's why a simple text-based BSOD or oops handler is a better idea than something that tries to do a whole bunch of cute graphics etc (which relies on a whole lot more hardware & software to be working properly).

Re:Keep it simple

[Sqwubbsy]

THis includes GUIs etc. That's why a simple text-based BSOD or oops handler is a better idea than something that tries to do a whole bunch of cute graphics etc (which relies on a whole lot more hardware & software to be working properly).

You are so not a Mac owner based on these statements.

Re:Keep it simple

[blaster]

The graphical version takes slightly fewer resources. You have to run a single buffer through an RLE decompression routine directly out into a linear mapped framebuffer. To display text you actually have to use all of the console code. Remember, there is no hardware console, so you have to actually do all the text element positioning in software, and the graphics card is in exactly the same mode either way.

It does not take appreciably more resources either way, and both code paths are fairly simple and well tested.

Re:Keep it simple

[Jahz]

Keep it simple AND keep it informative. A real BSOD will include information about the stop code and arguments at the time of death. If the system knows which driver caused the crash it will tell you this as well.
The Mac panic screen not only takes more resources to display but they tell you far less. "Please restart" in 23 different languages is not helpful. The 10.0 and 10.1 version looked much better.

Obviously you are NOT ready for the Mac. Come see the light, friend.

Do you really think that Apple have decided error codes and detailed crash reports are not important?? No, of course they have not. There are two reasons Apple does this.

1) The truth is that the infamous blue page of kernel farts that windows spews out are only to technicians or sysadmins. The home user, and in fact, the power users, can do nothing with it. Nothing, of course, except Google for the stop code and hope Microsoft has a techhelp article on what it means. You can reply to this and say that

STOP: 0x0000008E (c0000005, bf875fc3, f07bcd48, 00000000)
KERNEL_MODE_EXCEPTION_NOT_HANDLED

makes perfect sense to you... but you'd be lying. I know that the relevent part is 8E but 99% of users NEVER NEED TO SEE THIS and will NEVER USE IT.

Back to Apple. Apple has a little ditty called the "CrashReporter" and it has an OSX front-end to the system's log filed in /var/log/. The logs contain all the nitty gritty about what was in the registers when the sytem exploded, what driver/module caused it, etc readily and easily recorded in the system log. Said information (like STOP: 0x0000000000000000008E) is for a tech or sysadmin, not a standard user.

2) What do you do with the BSOD info displayed?? A true nooblar would write it all down. That's a waste of time, becuase its also in Windows' system log. Assuming you're going to Google for it, you would presumably reboot the machine, right? So why did we even need to see the error when it happened? The machine is up not, and the logs are visible...??

Bottom line: Apple's goal is to keep things simple, clean and friendly. What would your parents rather see?

1. A pleasant semi-transparent overlay that asks them to reboot their machine (in their native language)
2. A solid blue screen reading "KERNEL_MODE_EXCEPTION_NOT_HANDLED" followed by 30 rows of random-like numbers

Which one?

P.S. - Don't even think about saying "what happens if you cant boot." If that is the case, remove the new hardware. Otherwise you are in DEEP trouble... the code doesnt really matter and you'd actually be better off reading the error from /var/log.

Re:Keep it simple

[jericho4.0]

Regarding your first point; I'm more than a power user. I can actually figure out what those funny numbers mean. But, I never, ever, do. Who the hell does?

Re:Keep it simple

[ArwynH]

Real Programmers don't mix up array indexing and counting the length of an array.

And since the joke envolves the length of the array and not the index of it's last member, I guess the jokes on you.

Hidden?

[exp(pi*sqrt(163))]

hides the ugly kernel panics behind a nice looking GUI

It must hide them really well because in 4 or 5 years I haven't seen one. (I did once about 5 years ago though - that'll teach me to mess with third party USB drivers.)

Stupid boring new crash screen...

[Moofie]

That's not NEARLY as cool as the car crash sound Macs used to make when they really, really, REALLY blew up fierce. Get a good pair of speakers, and that sound would scare the tar out of everybody in the area!

I think it only happened to me once, on a junky old LCIII, while I was just working. There was a key combo to induce it on boot, though, and I got a lot of mileage out of that...

Gray screen of death

[azav]

I have gotten the gray screen of death twice on my Quad.

When capturing QuickTime video, QuickTime writes one copy of the file and then makes another. If you are capturing to a mastering codec (ie animation) minutes can become gigabytes. It is easy to fill up the internal HD in this case.

What can easily happen in this case is the file writing routines will start writing over allocated blocks. System files, even track zero. If it writes over track zero, your internal hard drive will be destroyed.

How do I know this? It happened to me twice.

The second time, I was left with a 17 GB file on my hard drive that can not be deleted by any means other than reformatting the disk. The first time it happened, the HD was borked so bad that plugging it into another Mac caused that mac to kernel panic. Apple replaced the drive but I lost everything minus my backups.

As I was told by an Apple tech, when a hd starts up the dirve itself checks the validity of track zero. If it is invalid, you have a hardware fault and this generates a kernel panic.

This was all validated by Apple techs.

You have been warned. Hope this helps someone.

Re:Gray screen of death

[slamb]

This has been a serious flaw in Unixes since I knew about it. The OS will let your HD fill up and overwrite itself. Many *nix flag wavers often defend this behaviour. Why they do is beyond me.

You're completely wrong. When the free space reaches 100%, write() will return ENOSPC (no space). The superuser will still be able to use the system, because traditionally, there's a 5% reserve which only uid=0 can use. (The "df" goes up to 105%.) The correct semantics are well-defined. If you've seen anything else, it's a bug in whatever system you were using, which no one could seriously defend.

Now, if you're talking about user applications breaking when encountering this condition...yeah, there are certainly some out there that break. There are buggy applications written for every platform. It's just laziness - Unix gives them well-defined semantics they can use to handle it correctly and an easy test environment (quotas).

Re:Gray screen of death

[blob.DK]

Excuse me, Sir, but that is a misunderstanding on your part. Mac OS X does not overwrite track zero just because the disk is full.

What you have experienced is the phenomenom of Mac OS X getting caught up in: "ups, the disk is full - so now I can't save any (system) preferences." Any files written during this will end up as zero-byte files.

There is no magic "QuickTime will overwrite vital systemfiles, to which only root has access"-routines.

Re:Gray screen of death

[glesga_kiss]

That's not the point. A malicious user can hose the entire system by running 'cat /dev/zero >> /opt/junk'. And I mean hose as in "system unusable, 100% of data lost"; the worst kind of hosed. The fact that Final Cut has options to manage this doesn't detract from the fact that the OS should manage itself better. Writing over track 0 on the HD? Creation of undeletable files? What is this, a return to the 8-bit days again?

When you get to 100MB free, the OS should tell the applications to go away. It should never fill 100% of the drive. Let's see you boot to remedy it when you can't write to log files.

Ultimate joke....

[ROMRIX]

"The article also shows the ultimate joke is to upload an actual BSOD image for authentic Windows looking panics right inside of OS X."

Ya! and then we could like, (snicker, snicker) we could like, bring up pictures of toilet paper on the monitor (snicker, snicker) and they would think (hehe, snicker) they would think they got T.P.'ed! HAHAHAHA!!!!!111!!!

Did anyone else just develop a twitch in their left eye?

Oligatory Monty Python Reference

[CrazyJim1]

If the aptly named blue screen of death is indeed the ultimate joke, people should die laughing at it.

Another promise Microsoft didn't keep...

[spywhere]

There were rumors, before XP came out, that they were going to respond to the iMac by making the Blue Screen of Death available in five designer colors.

Bah! You young punks!

[rocjoe71]

You young punks and blue-screens-of-panic blah, blah blah!

...In my day, we didn't even HAVE screens, just a blinking light and if that light ever stopped blinking, you knew there was trouble, boy...

Redmond...

[RAMMS EIN]

Redmond, start your photocopiers!

What happens if...

[mr_neke]

System encountered a kernel panic in the panic() function.

Cue infinite recursion...

Chairing a Meeting

[Pfhorrest]

I know it's off-topic, but I just had to share the image that came to mind when I first read this:

Once upon a time, I was chairing an out-of-town meeting with a roomful of engineers...

Picture, if you will, a meeting room filled with terrified engineers, all cowering behind one end of the table and desperately trying to shield their heads from ballistic chairs, being hurled by a Donkey-Kong like Steve Ballmer, who in turn is jumping up and down upon the far end of the table...

I know the Steve Ballmer jokes are old and off-topic (and I don't mean to compare you to him) but the image of "chairing" a meeting full of engineers was just to hilarious not to share. :-)

Becouse you all know...

[dark-br]

... Macs Crash Different

And don't get me wrong, I'm typing this on a Mac and I would not trade it for anything else out there ;)

Re:You want the ultimate joke?

[freedom_india]

Its NOT Funny, OK ???

Once we built a system for C*tibank (T+2) in FoxPro 2.6 for Windows and one of the users actually took a screenshot of the same, put it as background, and then complained our application doesn't work.

We spent 2 FULL days debugging the damn application before we realized the issue.

Oh.... &&%%$$&&