Anatomy of the Linux Boot Process 170
Donna writes "This article discusses detailed similarities and differences involved in booting Linux on an x86-based platform (typically a PC-compatible SBC) and a custom embedded platform based around PowerPC, ARM, and others. It discusses suggested hardware and software designs and highlights the tradeoffs of each. It also describes important design pitfalls and best practices."
The good thing about Linux (Score:5, Insightful)
Re:The good thing about Linux (Score:5, Insightful)
Or hardware installation
Re:The good thing about Linux (Score:1, Interesting)
It did't die. It actually detected it, installed the drivers, and the link went up. The old drivers simply threw up an "im not working" error in the device manager.
Re:The good thing about Linux (Score:3, Funny)
Re:The good thing about Linux (Score:2)
I don't use that NIC or Windows anymore, but credit where credit is due.
Re:The good thing about Linux (Score:1)
Re:The good thing about Linux (Score:2, Insightful)
Or a process stuck in I/O wait.
Or NFS gets confused.
Humility and knowledge of one's own weaknesses please!
Re:The good thing about Linux (Score:2)
Real men just use a hex editor on /proc/kcore to remove the process. :-)
Re:The good thing about Linux (Score:5, Funny)
About that... I've unsuccessfully tried hotswapping an AGP video card once... I spent the rest of the day looking up motherboard, ram, and video card prices online... using another computer... I'll let you figure out why...
Re:The good thing about Linux (Score:1, Redundant)
Re:The good thing about Linux (Score:1, Interesting)
unsuccessfully tried hotswapping an AGP video card once... I spent the rest of the day looking up motherboard, ram, and video card prices online
Ah, it's not for softies, but hot-swapping a peripheral card has been done [folklore.org].
Re:The good thing about Linux (Score:3, Funny)
I think I need to write a poem.
PS. be careful what web page you were viewing at the time, as it isn't so easy to close.
Re:The good thing about Linux (Score:2)
Re:The good thing about Linux (Score:2)
Kjella
Re:The good thing about Linux (Score:5, Insightful)
It would especially be useful on laptops, or for people who like to save electricity by shutting down their computers when not in use.
Re:The good thing about Linux (Score:3, Insightful)
It would probably be most useful for the Linux kernel developers themselves.
-a
or ispell upgrade (Score:2)
What a Debian system looks like when booting (Score:5, Interesting)
Originally posted on the debian-devel list: http://lists.debian.org/debian-devel/2004/11/msg00 547.html [debian.org]
Re:What a Debian system looks like when booting (Score:4, Informative)
Basically, they found that rhgb (which is often turned off by Redhat Engineers) is wasting a lot of time and doesn't accomplish anything. Removing it would increase bootspeed.
Re:What a Debian system looks like when booting (Score:4, Interesting)
Or, you could post to the article that inspired yours(and was cited in it), regarding the Fedora boot process.
That was not my post. I just remember seeing it on debian-devel. Besides, the if you follow the links from the fedora-devel post you refer to, all you get is a couple of png images of the boot processes. The guy who did the Debian version explains how he did it and also provides links to the necessary tools.
Re:What a Debian system looks like when booting (Score:2, Informative)
That's because the project just started then. Here's the project page now with documentation and more samples:
www.bootchart.org [bootchart.org]
Proof reading? (Score:5, Insightful)
Re:Proof reading? (Score:1)
Glad somebody else noticed that, atleast it was only in the x86 section. I figure the author was trying to research how many readers who click on the link look at the FA and are not part of some Cultural Denial Of Service attack.
How many of you have clicked on a link just to hurt the server? How many have clicked refresh just to see how long the server stays up?
Feel free to post anonymously if you're ashamed.
Re:Proof reading? (Score:4, Informative)
I have a computer science degree (Score:5, Funny)
Re:I have a computer science degree (Score:3, Funny)
If you had an EE degree, you might find it more interesting... but then likely everyone else would find *you* boring as hell.
Arrows (Score:5, Interesting)
Anyway, I've often wondered why the OS insists on redetecting hardware when BIOS does it for me already. I've heard that the LinuxBios actually does away with the hardware detect phase; leaving it solely to the kernel.
If the most popular OSes out there are taking care of HW at the high level, why haven't BIOS makers taken advantage of this to reduce their workload?
Re:Arrows (Score:2, Informative)
Re:Arrows (Score:5, Insightful)
Re:Arrows (Score:3, Insightful)
Because if you buy a motherboard and the BIOS on it makes it so that the computer will only work with Windows XP, server 2k3 and linux kernel 2.4+ people will be pissed. Some people might still want to run DOS, OS/2, Windows 95/98, kernel 2.2, or some other old busted operating system. It's there for that reason. With a linux bios your computer can pretty m
Re:Arrows (Score:4, Informative)
Re:Arrows (Score:3, Interesting)
The OS just asks the BIOS for a list of PCI ID values, and loads the appropriate drivers for those IDs.
Re:Arrows (Score:1)
Re:Arrows (Score:2)
One of the reasons for the OS redetecting hardware is that relying on the BIOS is less portable,
Very true, but very ironic considering that BIOS was supposed to be the magic compatability layer.
Re:Arrows (Score:3, Informative)
But it doesn't have to be efficient at any of it, because you're not going to do
Re:Arrows (Score:2)
I'm actually glad that it does. We did the TiVo hack, and our bios didn't see the tivo harddrive at all. Luckily, linux saw it just fine and was able to mount it without a problem.
Re:Arrows (Score:2)
My BIOS sees that I have one 1GB disk; linux sees that I have a 1GB disk to boot off and a 120GB disk for data -- software is much more flexible than firmware, to the point where I wonder quite why we have the latter...
Re:Arrows (Score:2)
Because many BIOSes are crappy, and mis-initialize the hardware. Haven't you ever seen boot messages like "Broken BIOS screwed up ATA PIO mode, fixing..." or something along those lines?
The BIOS is there so that boot code can print stuff on the screen and find the hard drive to boot the OS. Nothing else. It attempts to initialize hardware but it is not to be trusted.
If the most popular OSes out the
acronymfinder.com didn't help (Score:1, Insightful)
Re:acronymfinder.com didn't help (Score:2, Informative)
-D
Re:acronymfinder.com didn't help (Score:2, Informative)
Re:acronymfinder.com didn't help (Score:3, Informative)
Re:acronymfinder.com didn't help (Score:2)
Imposter!!! (Score:1, Funny)
You're not a nerd! I bet you even have a girlfriend and/or tattoo!
describes important design pitfalls (Score:1, Interesting)
Like, you know, a monolithic kernel?
Re:describes important design pitfalls (Score:4, Funny)
Linux Boot (Score:2, Interesting)
Re:Linux Boot (Score:3, Insightful)
Re:Linux Boot (Score:2)
Re:Linux Boot (Score:2)
Re:Linux Boot (Score:2)
For Debian users, there is a slightly easier way [virgilio.it], but still involves the commandline stuff
More discussion? (Score:4, Interesting)
The article makes an interesting read (although the server is getting slow already), but it seems a bit short on commentary. I'm no expert on the low-level systems of Linux, so the bare facts are quite interesting, but I would have been more interested to read a comparison of the merits of the different systems.
My impression, from the article, is that x86 versions of Linux are carrying quite a lot of legacy (from DOS et al). Does this mean that Linux on other architectures is "better" in any sense? I don't know, but I'd be interested if someone can inform.
Re:More discussion? (Score:2, Funny)
Once Linux has booted, it should not matter much.
It is more the overall architecture that is better in the sense that it is "cleaner".
For example, you don't need an extended/logical partition hack, you can have 32-64 equivalent partitions on a PowerPC with O
Speaking of linux booting... (Score:3, Insightful)
Re:Speaking of linux booting... (Score:3, Interesting)
Re:Speaking of linux booting... (Score:3, Insightful)
I know, I know, Debian isn't exactly your "grandmother's distribution", but the distro in question is pretty irrelevant once I get to the point.
Anyway, I set it up so they basically couldn't screw it up.
Re:Speaking of linux booting... (Score:2)
On a somewhat unrelated note, I have also not figured out why Mandrake 10.1 takes far longer to boot up on a much more powerful computer than my Mandrake 10.0 system.
Re:Speaking of linux booting... (Score:4, Insightful)
"On a somewhat unrelated note, I have also not figured out why Mandrake 10.1 takes far longer to boot up on a much more powerful computer than my Mandrake 10.0 system."
Somewhat unrelated ???!!!
Why don't you try pressing Escape just before the progress bar gets stuck, and find out which particular part of the boot process is causing all the delay. Mandrake may well be trying to set up some service or some piece of hardware that you don't actually use. If so, you can remove the item in question from you setup configuration. This probably explains why Mandrake 10.1 boots slower than 10.0 for you.
Re:Speaking of linux booting... (Score:2)
I wish that would work. With the old computer, I would make my choice in LILO, and it would instantly start booting. With the new one, I make my choice in LILO, and get this progress bar accross the bottom of the LILO screen, which inches accross while the computer appears to be doing absolutely nothing, gets stuck almost at the end, sits there a while, then launches into the graphical boot (where ESC does work). That part goes slow but no surprises there.
Re:Speaking of linux booting... (Score:3, Informative)
Just on the off-chance......got a motherboard that supports serial-ATA ? My kernel would hang for 30 seconds trying to detect a (non-existant) second ATA disk. Adding "hdg=noprobe" to the kernel boot line (/boot/grub/menu.lst in my case, maybe something like
Re:Speaking of linux booting... (Score:3, Informative)
Danial Howard
Re:Speaking of linux booting... (Score:5, Informative)
The most notable example I can give is Xandros. The booting process shows an animated Xandros logo with very general boot details such as detecting hardware... done, and Loading Kernel ... done.
The distros that usually don't offer a type of bootsplash by default are aimed for us power users because we want to know what's going on.
Re:Speaking of linux booting... (Score:2)
Speaking of Windows booting... (Score:2)
Re:Speaking of Windows booting... (Score:3, Informative)
Re:Speaking of Windows booting... (Score:1)
Re:Speaking of Windows booting... (Score:1)
you've got a problem with your install then. I routinly do that and have never ever had that happen
Login screen way to late. (Score:1, Informative)
You can even do it after pressing ESC. It is simpler to do that way.
Re:Login screen way to late. (Score:2)
You can even do it after pressing ESC. It is simpler to do that way.
I seem to recall Microsoft released a patch to fix that very problem. Though I haven't worked with a "fast" Win9x system for a while now. (where fast is better than a 800Mhz Celeron)
I always just disabled the splash screens in Win9x anyway, I think using TweakUI.
Re:Speaking of Windows booting... (Score:1)
Re:Speaking of linux booting... (Score:5, Informative)
If it's a server/professional workstation, the services boot loader is probably more useful. I'd sure like to have one on windows when I'm trying to troubleshoot a boot problem, without having to use safe mode - especially if the problem doesn't show up in safe mode...
Or something based off rhgb... (Score:2, Informative)
Gentoo bootsplash (Score:2)
Phillip.
Re:Speaking of linux booting... (Score:5, Interesting)
Re:Speaking of linux booting... babble (Score:2)
From the Apple ][e, to the Radio Shack Tandys, to MS-DOS 3.3, to Windows 98, these highly sucess
funny.... (Score:2, Funny)
kinda fun in an admittedly strange way, it's also cool to see how your leet speed reading is, if you can keep up.
Re:Speaking of linux booting... (Score:2, Informative)
Re:Speaking of linux booting... (Score:2)
Progress bars are from hell, I can't believe you suggested that.
Fire safety and misdirected arrows? (Score:3, Funny)
Time to stop trusting that the arrows if emergency exit signs are right now too?
Re:Fire safety and misdirected arrows? (Score:2)
don't like the splash screens (Score:3, Interesting)
Damn right (Score:2, Funny)
Frickin' noobs, eh?
Re:don't like the splash screens (Score:2)
Splash screens when things go wrong (Score:1)
The same applies to boot splash screens. The verbose screen lets you know exactly where a fault is occurring, so you have some hope of fixing it.
You also get a much better idea of how far you are from a useful desktop, by seeing the service names. A simple progress meter rarely updates consistently, so it
Re:don't like the splash screens (Score:3, Insightful)
I mean isn't Linux all about choice and configurability?
Re:don't like the splash screens (Score:3, Insightful)
The BSD boot process (Score:5, Funny)
1) birth
2) death (confirmed by netcraft)
Should be "BIOS" vs. "known hardware" (Score:5, Informative)
Having written a few embedded bootloaders (and modified some others), I will say that booting an embedded device is far far easier than booting a device who's hardware (that is critical to booting) can change between boots.
Re:Should be "BIOS" vs. "known hardware" (Score:3, Interesting)
So it should be possible to store an HW description into a small flash and boot *fast*, without having to discover hardware, and if the user want to add new critical "cold-plug" hardware (such as boot disk), he would just have to hit Del at the boot, and then a HW discover would be made..
Re:Should be "BIOS" vs. "known hardware" (Score:2)
Re:Should be "BIOS" vs. "known hardware" (Score:2)
Perhaps there could be a BIOS Parameter to switch to "intelligent OS" to get the BIOS to skip Hardware Detection.
Actually, it doesn't look like hardware detection is the cause of the big delays in BIOS. LinuxBIOS accomplishes that in a fraction of a second.
The big delay seems to be truly horrible code, pointless self testing (I'll know the video is bad when I don't see a picture!) no reasonable standards for resource allocation between the many modular componants of BIOS requiring each module to dupl
Re:Should be "BIOS" vs. "known hardware" (Score:2)
Stop plagiarizing! (Score:4, Insightful)
From the Slashdot submission:
And from the actual article: Replacing the string "This installment of "Migrating from x86 to PowerPC"" with "This article" and replacing the word "between" with the phrase "involved in" is not sufficient to serve as summarization in the submitter's own words. Somehow I have a hard time believing that the submitter "Donna" and the article author Lewin Edwards are one and the same person. If I'm wrong, then fine. You can't plagiarize yourself. If I'm correct, then Slashdot's done it again. The article summary isn't an original work by Donna, but a minor modification of the article author's own summary, and should be properly attributed as such.Re:Stop plagiarizing! (Score:3, Insightful)
My boot process (Score:5, Funny)
Re:My boot process (Score:2)
10:02:08 up 218 days, 21:51, 6 users, load average: 0.17, 0.08, 0.07
bootchart site moved. (Score:2, Interesting)
Bootchart is actually some of the coolest use of graphical display of data I have seen in a while:
bootchart [bootchart.org]
Some of the Solaris 10 guys even used it to improve the boot process on new releases of Solaris 10.
The latest updates (as of a few days ago) continued to streamline the system.
Why isn't the PC BIOS fully 32-bit yet? (Score:2)
Re:The article: (Score:1, Funny)
Re:The article: (Score:4, Funny)