Every Linux distribution embodies some more or less clever hack for circumventing the normal boot process and causing your computer, when it is turned on, to organize itself, not as a PC running Windows, but as a "host" running Unix. This is slightly alarming the first time you see it, but completely harmless. When a PC boots up, it goes through a little self-test routine, taking an inventory of available disks and memory, and then begins looking around for a disk to boot up from. In any normal Windows computer that disk will be a hard drive. But if you have your system configured right, it will look first for a floppy or CD-ROM disk, and boot from that if one is available.

Linux exploits this chink in the defenses. Your computer notices a bootable disk in the floppy or CD-ROM drive, loads in some object code from that disk, and blindly begins to execute it. But this is not Microsoft or Apple code, this is Linux code, and so at this point your computer begins to behave very differently from what you are accustomed to. Cryptic messages began to scroll up the screen. If you had booted a commercial OS, you would, at this point, be seeing a "Welcome to MacOS" cartoon, or a screen filled with clouds in a blue sky, and a Windows logo. But under Linux you get a long telegram printed in stark white letters on a black screen. There is no "welcome!" message. Most of the telegram has the semi-inscrutable menace of graffiti tags.

Dec 14 15:04:15 theRev syslogd 1.3-3#17: restart. Dec 14 15:04:15 theRev kernel: klogd 1.3-3, log source = /proc/kmsg started. Dec 14 15:04:15 theRev kernel: Loaded 3535 symbols from /System.map. Dec 14 15:04:15 theRev kernel: Symbols match kernel version 2.0.30. Dec 14 15:04:15 theRev kernel: No module symbols loaded. Dec 14 15:04:15 theRev kernel: Intel MultiProcessor Specification v1.4 Dec 14 15:04:15 theRev kernel: Virtual Wire compatibility mode. Dec 14 15:04:15 theRev kernel: OEM ID: INTEL Product ID: 440FX APIC at: 0xFEE00000 Dec 14 15:04:15 theRev kernel: Processor #0 Pentium(tm) Pro APIC version 17 Dec 14 15:04:15 theRev kernel: Processor #1 Pentium(tm) Pro APIC version 17 Dec 14 15:04:15 theRev kernel: I/O APIC #2 Version 17 at 0xFEC00000. Dec 14 15:04:15 theRev kernel: Processors: 2 Dec 14 15:04:15 theRev kernel: Console: 16 point font, 400 scans Dec 14 15:04:15 theRev kernel: Console: colour VGA+ 80x25, 1 virtual console (max 63) Dec 14 15:04:15 theRev kernel: pcibios_init : BIOS32 Service Directory structure at 0x000fdb70 Dec 14 15:04:15 theRev kernel: pcibios_init : BIOS32 Service Directory entry at 0xfdb80 Dec 14 15:04:15 theRev kernel: pcibios_init : PCI BIOS revision 2.10 entry at 0xfdba1 Dec 14 15:04:15 theRev kernel: Probing PCI hardware. Dec 14 15:04:15 theRev kernel: Warning : Unknown PCI device (10b7:9001). Please read include/linux/pci.h Dec 14 15:04:15 theRev kernel: Calibrating delay loop.. ok - 179.40 BogoMIPS Dec 14 15:04:15 theRev kernel: Memory: 64268k/66556k available (700k kernel code, 384k reserved, 1204k data) Dec 14 15:04:15 theRev kernel: Swansea University Computer Society NET3.035 for Linux 2.0 Dec 14 15:04:15 theRev kernel: NET3: Unix domain sockets 0.13 for Linux NET3.035. Dec 14 15:04:15 theRev kernel: Swansea University Computer Society TCP/IP for NET3.034 Dec 14 15:04:15 theRev kernel: IP Protocols: ICMP, UDP, TCP Dec 14 15:04:15 theRev kernel: Checking 386/387 coupling... Ok, fpu using exception 16 error reporting. Dec 14 15:04:15 theRev kernel: Checking 'hlt' instruction... Ok. Dec 14 15:04:15 theRev kernel: Linux version 2.0.30 (root@theRev) (gcc version 2.7.2.1) #15 Fri Mar 27 16:37:24 PST 1998 Dec 14 15:04:15 theRev kernel: Booting processor 1 stack 00002000: Calibrating delay loop.. ok - 179.40 BogoMIPS Dec 14 15:04:15 theRev kernel: Total of 2 processors activated (358.81 BogoMIPS). Dec 14 15:04:15 theRev kernel: Serial driver version 4.13 with no serial options enabled Dec 14 15:04:15 theRev kernel: tty00 at 0x03f8 (irq = 4) is a 16550A Dec 14 15:04:15 theRev kernel: tty01 at 0x02f8 (irq = 3) is a 16550A Dec 14 15:04:15 theRev kernel: lp1 at 0x0378, (polling) Dec 14 15:04:15 theRev kernel: PS/2 auxiliary pointing device detected -- driver installed. Dec 14 15:04:15 theRev kernel: Real Time Clock Driver v1.07 Dec 14 15:04:15 theRev kernel: loop: registered device at major 7 Dec 14 15:04:15 theRev kernel: ide: i82371 PIIX (Triton) on PCI bus 0 function 57 Dec 14 15:04:15 theRev kernel: ide0: BM-DMA at 0xffa0-0xffa7 Dec 14 15:04:15 theRev kernel: ide1: BM-DMA at 0xffa8-0xffaf Dec 14 15:04:15 theRev kernel: hda: Conner Peripherals 1275MB - CFS1275A, 1219MB w/64kB Cache, LBA, CHS=619/64/63 Dec 14 15:04:15 theRev kernel: hdb: Maxtor 84320A5, 4119MB w/256kB Cache, LBA, CHS=8928/15/63, DMA Dec 14 15:04:15 theRev kernel: hdc: , ATAPI CDROM drive Dec 15 11:58:06 theRev kernel: ide0 at 0x1f0-0x1f7,0x3f6 on irq 14 Dec 15 11:58:06 theRev kernel: ide1 at 0x170-0x177,0x376 on irq 15 Dec 15 11:58:06 theRev kernel: Floppy drive(s): fd0 is 1.44M Dec 15 11:58:06 theRev kernel: Started kswapd v 1.4.2.2 Dec 15 11:58:06 theRev kernel: FDC 0 is a National Semiconductor PC87306 Dec 15 11:58:06 theRev kernel: md driver 0.35 MAX_MD_DEV=4, MAX_REAL=8 Dec 15 11:58:06 theRev kernel: PPP: version 2.2.0 (dynamic channel allocation) Dec 15 11:58:06 theRev kernel: TCP compression code copyright 1989 Regents of the University of California Dec 15 11:58:06 theRev kernel: PPP Dynamic channel allocation code copyright 1995 Caldera, Inc. Dec 15 11:58:06 theRev kernel: PPP line discipline registered. Dec 15 11:58:06 theRev kernel: SLIP: version 0.8.4-NET3.019-NEWTTY (dynamic channels, max=256). Dec 15 11:58:06 theRev kernel: eth0: 3Com 3c900 Boomerang 10Mbps/Combo at 0xef00, 00:60:08:a4:3c:db, IRQ 10 Dec 15 11:58:06 theRev kernel: 8K word-wide RAM 3:5 Rx:Tx split, 10base2 interface. Dec 15 11:58:06 theRev kernel: Enabling bus-master transmits and whole-frame receives. Dec 15 11:58:06 theRev kernel: 3c59x.c:v0.49 1/2/98 Donald Becker http://cesdis.gsfc.nasa.gov/linux/drivers/vortex.html Dec 15 11:58:06 theRev kernel: Partition check: Dec 15 11:58:06 theRev kernel: hda: hda1 hda2 hda3 Dec 15 11:58:06 theRev kernel: hdb: hdb1 hdb2 Dec 15 11:58:06 theRev kernel: VFS: Mounted root (ext2 filesystem) readonly. Dec 15 11:58:06 theRev kernel: Adding Swap: 16124k swap-space (priority -1) Dec 15 11:58:06 theRev kernel: EXT2-fs warning: maximal mount count reached, running e2fsck is recommended Dec 15 11:58:06 theRev kernel: hdc: media changed Dec 15 11:58:06 theRev kernel: ISO9660 Extensions: RRIP_1991A Dec 15 11:58:07 theRev syslogd 1.3-3#17: restart. Dec 15 11:58:09 theRev diald[87]: Unable to open options file /etc/diald/diald.options: No such file or directory Dec 15 11:58:09 theRev diald[87]: No device specified. You must have at least one device! Dec 15 11:58:09 theRev diald[87]: You must define a connector script (option 'connect'). Dec 15 11:58:09 theRev diald[87]: You must define the remote ip address. Dec 15 11:58:09 theRev diald[87]: You must define the local ip address. Dec 15 11:58:09 theRev diald[87]: Terminating due to damaged reconfigure.

The only parts of this that are readable, for normal people, are the error messages and warnings. And yet it's noteworthy that Linux doesn't stop, or crash, when it encounters an error; it spits out a pithy complaint, gives up on whatever processes were damaged, and keeps on rolling. This was decidedly not true of the early versions of Apple and Microsoft OSes, for the simple reason that an OS that is not capable of walking and chewing gum at the same time cannot possibly recover from errors. Looking for, and dealing with, errors requires a separate process running in parallel with the one that has erred. A kind of superego, if you will, that keeps an eye on all of the others, and jumps in when one goes astray. Now that MacOS and Windows can do more than one thing at a time they are much better at dealing with errors than they used to be, but they are not even close to Linux or other Unices in this respect; and their greater complexity has made them vulnerable to new types of errors.


Перейти на страницу:
Изменить размер шрифта: