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Newsgroups: comp.os.linux,comp.os.linux.announce,comp.answers,news.answers Path: senator-bedfellow.mit.edu!enterpoop.mit.edu!spool.mu.edu!uwm.edu!ux1.cso.uiuc.edu!howland.reston.ans.net!agate!doc.ic.ac.uk!warwick!uknet!mcsun!julienas!geocub!labri.greco-prog.fr!corsini From: corsini@labri.greco-prog.fr Subject: Linux Frequently Asked Questions 3/6 [monthly posted] Message-ID: <PART3_739718152@geocub.greco-prog.fr> Followup-To: poster Summary: Linux, a small and free unix-like for 386-AT computers. Sender: corsini@greco-prog.fr (Marc-Michel CORSINI) Reply-To: linux@numero6.greco-prog.fr Organization: Greco Prog. CNRS & LaBRI, Bordeaux France References: <PART2_739718152@geocub.greco-prog.fr> Date: Thu, 10 Jun 1993 13:16:34 GMT Approved: news-answers-request@MIT.Edu Expires: Sat, 24 Jul 1993 13:15:52 GMT Lines: 1058 Xref: senator-bedfellow.mit.edu comp.os.linux:45694 comp.os.linux.announce:772 comp.answers:943 news.answers:9274 Archive-name: linux-faq/part3 Last-Modified: 93/06/1 Version: 1.19 ********************************************************* * * * Answers to Frequently asked questions about Linux * * * ********************************************************* This post contains Part 3 of the Linux FAQ (6 parts). It must be read *after* the 2 first parts. ===================================8<====>8============================ CONTENTS (of this part) VI. MISCELLANEOUS HINTS (part3) VII. MORE HINTS (part3) ===================================8<====>8============================ VI. MISCELLANEOUS HINTS ======================= *** This section is maintained by Matt Welsh (mdw@tc.cornell.edu). Please *** mail me if you have any changes/updates/questions. Thanks -mdw Special gcc information are located in section IX. A special section is devoted to it since it's *the* compiler of Linux. I have subsectionned this part in 3 subsections: VI.A Misc Information VI.B Minor/Major Information VI.C Serial Information VI.A. Misc information ~~~~~~~~~~~~~~~~~~~~~~ VI.01) It seems that $#@! ported on linux don't run correctly, what do I do about reporting bugs? ANSWER: (Matt Welsh) It's possible that either the program itself has a bug or that Linux has a problem that this program brings out. :) But first check that the size of the file(s) corresponds that of the files(s) on the FTP sites where it's available. If they're different, either you downloaded them incorrectly (i.e. you forgot to turn on "bin") or whoever put them on the FTP site uploaded them incorrectly. If that's not the problem, then post to comp.os.linux asking about the program, to verify that it is a bug. PLEASE: when posting possible "bug reports" include all error and output information from running/compiling the program. Just saying "it doesn't work" isn't very helpful. Also mention your specific setup, Linux version, GCC version, etc. Some of these things depend on running under certain versions and you may have missed that information. Note that my "ml-linux-bugs@dg-rtp.dg.com" bug reporting list has been phased out. It turns out that Linux has so few bugs, most of which are resolved on the newsgroup or through Linus before I can accumulate them and post. :) In short: if there's a bug in Linux or in Linux-ported software, it will usually be fixed in the next patchlevel or version. VI.02) Has $#@! been ported to Linux? ANSWER: First check out the FTP sites and read the monthly INFO-SHEET, as well as the new "Linux News" and the META-FAQ's (all of which are either available on the FTP sites and/or posted to the newsgroup as they're written). Also check out the "Linux Project Registry" (posted to the newsgroup and on the FTP sites) which lists ongoing/current Linux projects. Also look in the "old" Linux digests and mailing-list archives, kept on tsx-11.mit.edu and nic.funet.fi. Also, see if there's a GNU(*) version of the program you're looking for (which are available everywhere). Since Linux uses GCC as its native compiler, most GNU software ports directly to Linux without problems. If all else fails, ask on the mailing list or newsgroup if the program is ported and where it's available. (*) GNU stands for GNU's Not Unix, which (besides being a recursive acronym) is a project started by the Free Software Foundation (the FSF) to write a freely distributable version of Unix. The GNU kernel is named HURD, and is based on Mach. It is currently being written, and is not yet done. Many of the GNU utilities, however, are completed and are much more functional than the original Unix utilities. Since they are freely available, Linux is using them as well. VI.03) I've ported $#@! to Linux, what should i do to add it in the standard distribution? ANSWER: (Matt Welsh) First read the previous Q/A, then talk to the maintainers of the various releases (MCC interim, SLS, and so on) about including your program with those releases. The best way to make programs available to the rest of the world is to upload it to one of the Linux FTP sites (such as tsx-11.mit.edu:/pub/incoming or sunsite.unc.edu:/pub/Linux/Incoming). BTW Whenever you submit binaries, please think that if you link them with shared libraries, this might cause problems for those who (gasp!) don't have the shared libraries installed. You can either link them using -static, and if someone wants to build a shared version on their own machine they can get the sources (which you should also make available) and build it themself. Or else provide the shared lib. VI.04) I want to port $#@! to Linux, what are the flags? ANSWER: Recall that Linux implements subset of SYSV and POSIX, so -DUSG and -DPOSIX work in general. NOTE1: SIGBUS is not there, and can be safely commented out in general. NOTE2: see section related to GCC, in the third part of this FAQ, for more details. VI.B. Major/Minor device number ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ *** This section is maintained by Rick Miller, any comments, *** suggestions, remarks should be mailed to him at <rick@ee.uwm.edu> *** Last Update: April 1993 This is a list of the device names, along with Major and minor numbers, which the Linux kernel may currently recognize. I say "may" because some of them may require patches to your kernel, others must be configured-in using the Linux kernel's "make config" routine before compiling. My profuse thanks to all the writers of device drivers for Linux, and to all those patient folks who took the time to explain their devices to me. May they become obscenely rich. Until then, I hope this list will help prevent driver collisions and perhaps lend a clue to a newbie or two. IF YOU WANT ANY CHANGES OR ADDITIONS TO THIS LIST, *TELL ME*! DEVICES NOT LISTED HERE SHOULD USE MAJOR NUMBERS *ABOVE 127* UNTIL ALLOCATED A MORE PERMANENT NUMBER IN THE LOWER RANGE. (I suggest using a more-or-less random number to avoid the chance of collisions with any other experimental drivers.) TO HAVE MAJOR/MINOR NUMBERS ALLOCATED (OFFICIALLY) FOR YOUR DEVICE DRIVER, SEND E-MAIL TO: RICK@EE.UWM.EDU VI.05) What are the device minor/major numbers? Majors: 0. Unnamed ....... (unknown) .... for proc-fs, NFS clients, etc. (???) 1. Memory ........ (character) .. mem ramdisk kmem null port zero core 2. Floppy ........ (block) ...... fd[0-3]<[dhDH]{360,720,1200,1440}> 3. AT-Disk ....... (block) ...... hd[a-b]<[0-8]> 4. Tty ........... (character) .. tty's and pty's 5. Dial-out ...... (character) .. tty cua* 6. Parallel ...... (character) .. par[0-2] lp[0-2] 8. SCSI-Disk ..... (block) ...... sd[a-h]<[0-8]> 9. SCSI-Tape ..... (character) .. <n>st[0-1] or <n>rmt[0-1] 10. Mouse ......... (character) .. logibm psaux inportbm atibm (mouse) 11. CD-ROM ........ (block) ...... scd[0-1] 12. QIC-tape? ..... (character) .. rmt{8,16} tape<{-d,-reset}> 13. XT-disk ....... (block) ...... xd[a-b]<[0-8]> 14. Audio ......... (character) .. audio dsp midi mixer sequencer 15. Joystick ...... (character) .. js[0-1] 16. Socket ........ (character) .. net arp 17. AF_UNIX ....... (character) .. unix 18. AF_INET ....... (character) .. inet ip icmp tcp udp 19. WE-driver ..... (character) .. we[0-3] 20. DP8390-driver . (character) .. wd[0-3] ec[0-3] ne[0-3] 21. Sony-CD-ROM ... (block) ...... sonycd 22. 2nd AT-Cntrlr . (block) ...... hd1[a-b]<[0-8]> 23. Mitsumi CD-ROM (block) ...... mcd 31. Link Interface (character?) . ??? Breakdown of minors by Majors: ------------------------------ 0. Unnamed ....... (unknown) .... for proc-fs, NFS clients, etc. Minors? 1. Memory ........ (character) .. ram mem kmem null port zero core (0. /dev/ram: was supposed to be the ramdisk, but never got used. As of this date it has not been implemented and probably won't be.) 1. /dev/mem 1. /dev/ramdisk: a BLOCK device (the RAM-disk) 2. /dev/kmem 3. /dev/null 4. /dev/port 5. /dev/zero 6. /dev/core: like /dev/mem, but in "core"-file format for gdb 2. Floppy ........ (block) ...... fd[0-3]<[dhDH]{360,720,1200,1440}> Minors are [[4 * type] + drive] where drive 0-3 == A:-D: (floppy) and type is: 0: Autodetect 4: 720k on 3.5" DD 1: 360k on 5.25" DD 5: 360k on 5.25" HD 2: 1.2M on 5.25" HD 6. 720k on 5.25" HD 3: 360k on 3.5" DD 7. 1.44M on 3.5" HD 0. /dev/fd0: Autodetected first floppy. 1. /dev/fd1: Autodetected second floppy. 2. /dev/fd2: Autodetected third floppy. 3. /dev/fd3: Autodetected fourth floppy. 4. /dev/fd0d360: 360k on 5.25" DD in first drive 5. /dev/fd1d360: 360k on 5.25" DD in second drive (You can work out the rest of the intermediates...) 8. /dev/fd0h1200: 1.2M on 5.25" HD in first drive 12. /dev/fd0D360 (/dev/fd0H360): 360k on 3.5" DD in first drive 16. /dev/fd0D720 (/dev/fd0H720): 720k on 3.5" DD in first drive 20. /dev/fd0h360: 360k on 5.25" HD in first drive 24. /dev/fd0h720: 720k on 5.25" HD in first drive 28. /dev/fd0H1440: 1.44M on 3.5" HD in first drive Naming goes like this: fd[drive][media][size] where: [drive]=0-3: Corresponds to DOS's "A:"-"D:". [media]={d,h,D,H}: d=Double Density 5.25" diskette h=High Density 5.25" diskette D=Double Density 3.5" diskette H=High Density 3.5" diskette [size]={360,720,1200,1440} kilobytes. Floppies are assumed to be double-sided (DS), and drives are assumed to be high-density devices. 3. AT-Disk ....... (block) ...... hd[a-d]<[0-8]> (For IDE, MFM, and RLE drives and controllers.) On the first AT controller card: 0. /dev/hda (/dev/hda0): The whole first HD, including its MBR. 1-4. /dev/hda{1-4}: Primary partitions on the first hard drive. 5-8. /dev/hda{5-8}: Extended partitions on the first hard drive. 64. /dev/hdb (/dev/hdb0): The whole second HD, including its MBR. 65-68. /dev/hdb{1-4}: Primary partitions on the second hard drive. 69-72. /dev/hdb{5-8}: Extended partitions on the second hard drive. On the second AT controller card: 128. /dev/hdc (/dev/hdc0): The whole third HD, including its MBR. 129-132. /dev/hdc{1-4}: Primary partitions on the third hard drive. 133-136. /dev/hdc{5-8}: Extended partitions on the third hard drive. 192. /dev/hdd (/dev/hdd0): The whole fourth HD, including its MBR. 193-196. /dev/hdd{1-4}: Primary partitions on the fourth hard drive. 197-200. /dev/hdd{5-8}: Extended partitions on the fourth hard drive. Notes: BE *VERY* CAREFUL WITH the four "whole drive" devices (hda, hdb, hdc, and hdd)!! These four devices embody the *entire* *drive*, not just one partition. The only things that use them are things that need to read/change the partition table (like fdisk). Linux doesn't order anything. It perceives partitions in the order in which they appear in the partition table. Thus, /dev/hd?1 may follow /dev/hd?2 in the cylinder numbering. The names of the hard drives are not the same as under Minix. 4. Tty ........... (character) .. tty's and pty's 0. /dev/tty0: This is the currently active Virtual Console. 1-9. /dev/tty[1-9]: Specific virtual consoles. 10-63. /dev/ttyV[10-63]: More virtual consoles that nobody uses. 64-127. /dev/tty[0-?][0-63]: Dial-in serial ([controller][port]). 128-191. /dev/pty[p-s][0-f]: PTY Masters. 192-255. /dev/tty[p-s][0-f]: PTY Slaves. ([0-f]=0123456789abcdef) Notes: NOTICE THE NEW NAMING FOR SERIAL LINES. Serial lines will be named either "tty..." or "cua..." (See Major #5) followed by the one-digit number of the *board* the line is from, and the number of the line on that board. The four default lines are considered to be on board "0", so what DOS calls "COM2:" should now be known as "/dev/tty01" or "/dev/cua01". For more information on the use of multi-port boards, read the documentation which accompanies the serial patches. 5. Dial-out ...... (character) .. tty cua* 0. /dev/tty: the tty that owns the process calling it. 64-127. /dev/cua[0-?][0-63]: Dial-out serial ([controller][port]). (See Major #4 for NEW NAMING CONVENTION.) 6. Parallel ...... (character) .. par[0-2] lp[0-2] Parallel (printer) ports. (Increasable in include/linux/lp.h) 0. /dev/par0 (/dev/lp0): First XT parallel port 1. /dev/par1 (/dev/lp1): First AT parallel port 2. /dev/par2 (/dev/lp2): Second AT parallel port Notes: The number of line printers is defined by LP_NO which is found in [/usr/src]/linux/include/lp.h. 7. Unused. (First come, first serve.) This one's getting old. No minor numbers are yet assigned. It's not even in the source code. Maybe it never will be... 8. SCSI-Disk ..... (block) ...... sd[a-h]<[0-8]> Minors numbers are ((16 * Drive) + Partition) where Drive is the number of the physical drive in order of detection and Partition is as follows: 0 is the whole drive 1-4 are the DOS "primary" partitions 5-15 are the DOS "extended" (or "logical") partitions, so... 0. /dev/sda (/dev/sda0): The first (detected) SCSI drive. 1-4. /dev/sda[1-4]: Primary partitions on the first SCSI drive. 5-15. /dev/sda[5-15]: Extended partitions on the first SCSI drive. 16. /dev/sdb (/dev/sdb0): The second (detected) SCSI drive. 17-20. /dev/sdb[1-4]: Primary partitions on the second drive. 21-31. /dev/sdb[5-15]: Extended partitions on the second drive. 32. /dev/sdc (/dev/sdc0): The third (detected) SCSI drive. ...and so on. 9. SCSI-Tape ..... (character) .. <n>st[0-1] or <n>rmt[0-1] 0. /dev/st0: First (detected) SCSI tape drive, rewind-on-close. 1. /dev/st1: Second (detected) SCSI tape drive, rewind-on-close. 128. /dev/nst0: First (detected) SCSI tape, *no* rewind-on-close. 129. /dev/nst1: Second (detected) SCSI tape, *no* rewind-on-close. 10. Mouse ......... (character) .. logibm psaux inportbm atibm (mouse) (MGR may require that /dev/mouse be linked to one of these...) NOTE THE CHANGES TO DIFFERENTIATE MOUSE TYPES! (Please implement these in the distributions.) 0. /dev/logibm: Logitec-'compatible' bus mouse 1. /dev/psaux: PS/2 mouse port (may not work on some lap-tops, yet) 2. /dev/inportbm: MicroSoft "InPort" bus mouse 3. /dev/atibm: ATI XL bus mouse 11. CD-ROM ........ (block) ...... scd[0-1] 0. /dev/scd0: The first (detected) SCSI CD-ROM. 1. /dev/scd1: The second (detected) SCSI CD-ROM. ("There's not much more to it than that" says Eric Youngdale.) 12. QIC-tape? ..... (character) .. rmt{8,16} tape<{-d,-reset}> (I really don't have much info on this one... ) 6. /dev/rmt8: QIC-120 8. /dev/rmt16 (/dev/tape): QIC-150 136. /dev/tape-d: (It has something to do with being 128+8... ?) 255. /dev/tape-reset: For resetting only. 13. XT-disk ....... (block) ...... xd[a-b]<[0-8]> XT (8-bit) hard disk controller devices. Minor numbers are assigned in the same manner as for the normal (AT-type) Hard Drive devices ("/dev/hd*"). 14. Audio ......... (character) .. audio dsp midi mixer sequencer 0. /dev/mixer: Mixer and Control Device 1. /dev/sequencer: FM-synthesizer and Midi 2. /dev/midi: (for future use) 3. /dev/dsp: Digitized voice (DAC/ADC) 4. /dev/audio: (Reserved for compatibility with Sun) 15. Joystick ...... (character) .. js[0-1] 0. /dev/js0: (Left/Right?) joystick. 1. /dev/js1: (Right/Left?) joystick. 16. Socket ........ (character) .. net arp 0. /dev/net: Generic layer (sockets) 1. /dev/arp: Address Resolution Protocol (ARP) 17. AF_UNIX ....... (character) .. unix 0. /dev/unix: AF_UNIX protocol layer 18. AF_INET ....... (character) .. inet ip icmp tcp udp 0. /dev/inet: AF_INET protocol layer 1. /dev/ip: Inernet Protocol (IP) 2. /dev/icmp: Internet Control Message Protocol (ICMP) 3. /dev/tcp: Transmission Control Protocol (TCP) 4. /dev/udp: User Datagram Protocol (UDP) 19. WE-driver ..... (character) .. we[0-3] 0-3. /dev/we[0-3]: "WE" driver 20. DP8390-driver . (character) .. wd[0-3] ec[0-3] ne[0-3] 0-3. /dev/wd[0-3]: "DP8390" driver, WD8003 8-11. /dev/ec[0-3]: "DP8390" driver, 3C503 16-19. /dev/ne[0-3]: "DP8390" driver, NE2000 21. Sony-CD-ROM ... (block) ...... sonycd 0. /dev/sonycd: Sony CDU-535 CD-ROM, I think. 22. 2nd AT-Cntrlr . (block) ...... hd1[a-b]<[0-8]> Minor numbers are like those of the primary AT-Disk controller. THIS MAY WORK FOR HARD-CARDS. (Note the "1" in the device name for the secondary controller. This is because we may eventually wish to change the names of the primary-controller drives to "hd0[a-b]...".) 23. Mitsumi CD-ROM (block) ...... mcd I don't know much about this one. 31. Link Interface (character?) . ??? 0. ??? Link Interface for use with Christoph Niemann's driver for the INMOS C012-based high-speed serial link interface card (useful for talking to transputers or video digitizers). VI.06) (Chuck Boyer) Could some one clear up the devices meaning? ANSWER: (Jim Winstead Jr) >port This allows programs to access the hardware ports directly. Not something you generally mess around with much. >ptyp0-3 >ptypa...tty These are the pseudo-tty 'master' devices. Each pty connection uses a slave-master set of tty devices. >tty0... tty[1-8] are the virtual consoles associated with Alt-F[1-8]. tty0 is the current virtual console (so writing something to tty0 goes to the current vc). >tty64 I've figured out is the modem connection Yes, that would correspond to COM1 under DOS. However, the tty64 name is obsolete - ttys[1-4] should be used instead. >ttyp0... >ttypa... These are the pseudo-tty 'slave' devices. >ttys1... These are the serial devices. ttys1 corresponds to COM1 under DOS, ttys2 corresponds to COM2, etc. VI.C Special Serial ~~~~~~~~~~~~~~~~~~~ *** This section is maintained by Jim Gifford *** (jgifford@attmail,world.std}.com), some addenda were sent by *** Juha Ursin (jus@snakemail.hut.fi) *** Last update May 1993. Douglas E. Quale: This has come up a couple of times already (including the case of serial mice as well), but for the record stty acts on stdin not stdout. Old stty's (from V7 through BSD4.3) used stdout, but this is suboptimal and doesn't conform to POSIX. The GNU stty you are likely using on Linux uses stdin, as does the stty distributed with BSD Networking Release 2. (Also, ``stty -a'' is more informative about possible parameters, although it's pretty hard for me to remember what 90% of that stuff does without refering to the man page.) Jim Gifford: However, there are a few older (of mysterious origin) stty's that work on stdout(I have one myself!) VI.07) Is there a list somewhere where I can get help with serial communications under Linux? ANSWER: (Jim Gifford -- jgifford@world.std.com) There is a list for the discussion of serial communications under Linux. It is for problems, drivers, new developments, etc... with the Linux serial devices. The list is: linux-serial@stolaf.edu To join, send mail to linux-serial-request@stolaf.edu I hope that this list will prove beneficial to the improvement of Linux. This list is maintained by Michael K. Johnson as linux-serial-request@stolaf.edu VI.08) When I run kermit under Linux, I get "Warning, Read access to lock directory denied". What am I doing wrong? ANSWER: Nothing, you just need to create /usr/spool/uucp (kermit 4.6?) or /usr/spool/locks (this is for the kermit5A), which is where kermit like to lock files. VI.09) What are the major, minor numbers for the serial ports under linux? ANSWER: Major 4, Minor : 64 /dev/ttys0 - com1 65 /dev/ttys1 - com2 66 /dev/ttys2 - com3 67 /dev/ttys3 - com4 VI.10) can anyone give me a sample /etc/inittab entry for login from a pc attached to serial line /dev/ttys2? ANSWER: "Humberto speaking :), updated by Rick Miller" First set up the modem to turn off echo and enable auto answer, I do this in kermit by connecting to the modem and typing "ate0s0=1" followed by enter (w/o quotes). Then setup inittab to spawn getty on the modem ttys2:vt100:/etc/getty -m 1200 ttys2 (Replace "vt100" with the name of the /etc/termcap entry for the terminal type you will use, or use "dumb" if you don't have one.) Then it should work. Some modems can be permanently set to disable echo and set auto answer, see your manual. Jim Weigand says: disable all messages. This will prevent getty from hanging up your modem. Set For: ATE0 No echo ATQ1 No messages ATS0=2 Answer 2nd ring ATS7=60 1 minute to answer (shorter if 2400 baud) You can use kermit to set these. Do an AT&W to save for power-up. Michael K. Johnson says: If you would rather not save these commands as defaults to come up on power-up, perhaps because you want to use your current modem settings under a DOS communications package, you can also shove these command out ttys? from /etc/rc (or /etc/rc.local) using the command: echo "<modem_settings>" > /dev/ttys? VI.11) How do I set parameters like parity for serial login? ANSWER: Use stty and redirect input from the serial line. ex: stty parodd < /dev/ttys2 which gives ttys2 odd parity. type stty -a to get an idea of possible parameters. Or 'man stty' as well :) VI.12) (Juha Ursin) I run SLS pl6, kernel is pl8 and I use libc.4.3.2. Trying to allow login on my terminal (on ttyS1 with only three wires (RX, TX, GND) connected). Getty 9600 /dev/ttyS1 starts and I get the login prompt, but the password prompt newer appears. ANSWER: (Ted Ts'o) Setting CLOCAL is the correct way to solve this --- it is not a bug in the kernel. Since you only have three wires connected, it means that the carrier detect line was left floating, and probably floated to ground. Thus, the /dev/ttyS1 device blocked waiting for carrier detect to go high. The reason why the login prompt appeared is that getty opened /dev/ttyS1 with the NODELAY flag; but when /dev/ttyS1 was reopened for /bin/login, it did not have the NODELAY flag, and you ended up blocking. That's what the CLOCAL flag is for --- it indicates that the serial port is hooked up to a local (hence CLOCAL) terminal, and so the carrier detect line should be ignored. In general, whenever the carrier detect line is not supported by a serial device, or if your RS-232 cable does not support the CD wire, the CLOCAL flag should be set. VI.13) (Juha) Where are my Call-out-mode -serial ports (cuaX) ?, When should I use these cuaX ports ?, Why on my system ttys3 is used instead of ttyS3 ? ANSWER: (Ted) Ask the person who created the install procedure (Peter MacDonald, in the case of SLS). >When should I use these cuaX ports? When you're dialing out (i.e., kermit, cu, seyon, uucp, etc.). >On my configuration ttyS3 is named ttys3 incorrectly - why? Again, see the person who created the install procedure. Recent versions of SLS create the serial devices using the new convention (ttyS3). ttys3 represents an older convention, and some older install procedures may not have switched over. VI.14) (Juhan) What other possibly free IRQ's there are than IRQ5 ?, Can I use IRQ7 when not printing ?, ANSWER: (Ted) IRQ 2 is also often free, although some networking cares use them. > Can I use IRQ 7 when not printing? It's generally a bad idea to have two cards plugged in sharing an IRQ address. It happens to work with most serial cards, but it doesn't alwas work. You can use IRQ 7 if you don't have a parallel port plugged into your system. If you do have a parallel port plugged in, you can try using IRQ 7; it might work, it might not. Be sure to also make sure that the printer works after you plug in your serial card configured to use IRQ 7. Another alternative: If you are using the version of the parallel printer driver that doesn't use interrupts, you can go to your parallel port board, and disable the IRQ, thus freeing IRQ 7. Is pin 1 nearest to the plate or is it 31? If this is a sample PC ISA card, then A1 is the pin closest the "back" of the card, and on the top, if the pins are held down and the "back" of the card is to your right: ---------------------------------------------------------------------- | | | | | | | | | | | | +---------------------------------+ +---+ +---+ | | | | +----------+ +---------------+ A A 3 1 1 The "B1..B31" pins are on the reverse side of the card. VII. MORE HINTS =============== This part try to keep track of the different information that appeared in comp.os.linux and on the list since beginning of March. I tried to update it for KERNEL_VERSION, so there might be some mistakes. Moreover take care to use the correct library and include stuff, and the ad-hoc gcc you use !!! VII.01) How can I backup my Hd under Linux ? ANSWER: I know at least two ways. One possibility is tar and mtools, another possibility is the diskbackup/diskrestore of Diamano Bolla (digest37 vol. #2) which saves big hd to floppies using the stdin/stdout. These utilities have been uploaded to the major sites in file disksplit.tar.Z. An example usage (Roger Binns) is: tar cvf - bin dev usr etc .. | compress | diskbackup and to restore: diskrestore | uncompress | tar xvf - BTW: if you are on Ethernet you could send your files via tar..|rsh (tar...) or even via NFS to a host which is regularly backed up ! VII.02) Where is 'which' ? ANSWER: It depends on the sh you are running: in bash 'type -path' in tcsh it's a builtin for rc you can try the following (untested by me) script from Kevin Brown: #!/bin/sh for i in `echo $PATH | sed 's/:/ /g'` ; do for j in ""$@" ; do if test -x "$i/$j" ; then echo "$i/$j" fi done done VII.03) How to use setterm: for the novice? ANSWER:The setterm utility provides access to most of Virtual Consoles (VCs) functionality. You can set your screen up to blank at 10 minutes using: setterm -blank 10 You can set colors, and clear the screen. For a full list of commands, just type "setterm" with no arguments. There are a few tricks with the screen dumper can really make VCs go a long way. Here are a few of the common ones that I use: setterm dump Dumps the contents of the current VC to screen.dump (in the current dir). setterm dump 4 Dumps the contents of VC 4 to screen.dump setterm -file mydumpfile -dump 4 Dump the contents of VC 4 to the file mydumpfile setterm -file /dev/tty0 -dump 4 Dumps the contents of VC 4 to the current VC. setterm -file /dev/tty4 -dump Dumps the contents of the current VC to VC 4. setterm -file /dev/ttys1 -dump Dumps the contents of the current VC to the serial port. Handy if you are logged on and want to paste a screen full without having to resort to doing a file transfer. setterm -file mydumpfile -append 4 Appends to instead of overwriting the dump file. Useful if you have several screens you wish to concatenate. VII.04) I've tried clear/reset which exist on most of unix but it doesn't work, have I missed something? ANSWER: setterm -clear or setterm -reset will solve your missing. For clear, you can also write a small script (which use the cl: part of /etc/termcap wrt your TERM), or use bash where ctrl-l will do it for you. VII.05) I know there are VC, but where is the setterm stuff? ANSWER: It's in the current distribution (i.e. on the images), the source can be found in virtcons.tar.Z at nic. VII.06) I know there are shared libraries; does there exist an easy way to check an executable for sharing ? ANSWER: (Claude Morin:) There exists at tsx-11 ldd.tar.Z If you follow the instructions, you will be able to type "ldd <executable>" to List the Dynamic Dependencies of the executables. In other words 'ldd' prints the name of the shared libraries needed by the executable, nothing appears for static one. ANSWER: (Josh Yelon & HJ Lu) - very old binaries. (J.Y.) An executable which shares a library is linked with an (ordinary, non-shared) "stub" version of the library. One of the first thing this stub does (when the executable is run) is to ask the kernel to load the (big) "shared version" of the library (which is usually named /lib/lib.XX.XX) The upshot of this is that in the code for the stub (part of the executable), is the string "/lib/lib.XX.XX"; which can be searched by using 'strings' or 'grep'. (HJ. L.) if you have gcc2.11a or later the shared image is changed to /lib/libxxxx_vyy_zzz. And you should better use nm to find "__shared_lib" (nm failed on stripped executable). You can also write a function for "file", which can even check the version number .... VII.07) What is the rdev program provided in the images? ANSWER: It's a program from Werner Almesberger of ETH. With no argument it prints the first line of /etc/mtab. With one argument, a boot-image, it prints the device configured as the root device, and with two arguments, a boot image and a device, it sets the device as default root in the specified image. VII.08) How to start Linux from drive B? ANSWER: There is a DOS utility called boot_b.exe (look at DOS ftp). Another simple way is to open the box and invert the cables. VII.09) The program boot_b works fine /but/ once the first disk is read the system go back to the first drive, any hints? ANSWER: Yes, change the bootimage in just the same way that you change it to boot on the hard drive, execept that the major/minor pair is different. All these information are in the file INSTALL-0.10. Remember that if you use a sun or other endian machine, you will need to reverse the byte order when you run the filter program (also in the same file). VII.10) How can I get Linux to boot directly from the harddisk? ANSWER: (Rick) The best option right now is LILO version ALPHA.8. It has been generally agreed that the days of using "shoelace" are at an end. See Section III of this FAQ for LILO information. VII.11) I use shoelace, but I want to change my root partition, what is the process to get rid of it? ANSWER: With Norton utility you can put back a standard boot sector. Another possibility is to restore the old boot sector (the one you should have backup *before* installing shoelace). VII.12) Sometimes, when I want to remove a directory, I get an error message, is it a (known) bug? ANSWER: No, There is no bug at all, you probaly have another shell on another VC whose working directory is either the one you try to remove, either a subdirectory of it. VII.13) I'm looking for init, getty, login, passwd stuff, where can I find them? ANSWER: You should find it in shadow.tar.Z (only sources), at least at tsx in the usr.bin directory. Many people have reported some troubles with the *OLD* shadow-passwd (shadow-bin.tar.Z and shadow-src.tar.Z, so do not use them anymore); an alternative might be the mcc-interim which contains standard passwd binary. There is also the Peter Orbaek's admutil-1.?.tar.Z and poeigl-1.?.tar.Z which contains source for shutdown, su, chsh, passwd and a system V init compatible. VII.14) How can I setup a user account other than root ? ANSWER: You can either use the adduser program, either do it manually. In the later case, you have to: a) edit /etc/passwd as root and add a line of the following format: user:passwd:uid:gid:user name:home directory:login shell user is the login name; uid is the numeric user id, it should be unique; gid is the numeric group id, this number should correspond to an entry in /etc/group. The passwd field should be left blank 'cause it is stored in an encrypted form [to set this field just use the passwd program]. example faq::200:5:Marc-Michel:/home/faq:/bin/sh b) Still as root, you shoud now create the home directory and set the correct ownership. mkdir /home/faq chown faq /home/faq chgrp 5 /home/faq VII.15) I've been trying to get Linux to run on my [3/4]86 box. It can't even boot. Any suggestions? ANSWER: The most common error/problem is writing the bootimage to a low density disk. It fits, but the bootstrap code will only recognize high density disk. So try to format explicitely disk as high density: - for 3.5", 'format a: /n:18 /t:80 ' - for 5.25", 'format a: /n:15 /t:80 ' VII.16) Does there exist games, languages (other than C), and anything which make the system more friendly? ANSWER: Yes, among other things there are rogue and yahtzee; TeX; Prolog, Perl.. but in general, if you want some extra tool port it to Linux this is also a good beta-testing exercice. VII.17) Whenever I use uemacs 3.1X on a symlink, the symlink does not exist anymore, why? ANSWER: (Tristram Mabbs) Since ue3.10, uemacs uses 'safe save' mode, writing the file to a temporary and moving it OVER the original. In the process, this deletes the original. To prevent this just add the following in your emacs '.rc' file: set $ssave FALSE VII.18) I have an SVGA, but Linux detect an EGAc/EGAm; is it normal? ANSWER: (Jim Winstead) This is correct actually. You have an EGA+ card (SVGA) with a Color/Mono monitor. The only four possibilties are EGAc, EGAm, *MDA and *CGA (according to the code in kernel/chr_drv/console.c). The true test, if Linux detects your video card, is if you press <RETURN> at the "Press <RETURN> to see SVGA- ..." boot-time message. If you have a SVGA recognized card, it will ask you to choose a screen size. If not detected, the default is 80x50 mode. BTW if you have no SVGA, press the <space> and you are in 80x25 mode. If you have dowloaded the kernel, you can automatically skip this query at boot-time if you set the SVGA_MODE variable in the main Makefile before compiling a new bootimage. VII.19) How can I change the keyboard repeat rate? ANSWER: (Michael K Johnson) In boot/setup.S there are the lines: ! set the keyboard repeat rate to max mov ax,#0x0305 mov bx,0x0000 int 0x16 If you don't want to change the repeat rate at all, just comment out these lines. If you want something in the middle, change the mov bx,0x000 by mov bx,0x??yy where ??yy is determined by (Ralf Brown's interrupt list) bh= delay value (0x00 = 250ms to 0x03= 1000ms (one sec)) this is the delay before the repeat is performed bl= repeat rate (0x00 =30/sec to 0x1f=2/sec; 0x0c=10/sec [default]) VII.20) I compiled fdformat.c and ran it on 1.44Mb and 1.2Mb, the results are unreadable, any clue? ANSWER: (M. Pereckas) fdformat only low-level formats the disk. to use the fdformatted disk with DOS filesystem, run mformat on the disk. Mformat writes DOS filesystem information but is unable to low-format :). In order to put a Linux filesystem on a (low)formatted disk you have to mkfs it. VII.21) Is it possible to disable the 3-fingers salute (ctrl-alt-del) ? ANSWER: Yes, in kernel/sys.c you can read the following: /* * this indicates wether you can reboot with ctrl-alt-del: the deault is yes */ static int C_A_D = 1; there is also a small utility written by Linus in digest242 vol#2 VII.22) Could some one explain the information provided at boot-time? ANSWER: (Jim Winstead Jr) > serial port at 0x03f8 is a 16450 > serial port at 0x02f8 is a 16450 (what's that the uart chip?) Right, the last number should either be 8250, 16450, 16550, or 16550a, and on the two 16550 models, it will report that FIFO's have been disable (16550) or enabled (16550a). > 8 virtual consoles (that's how many alt-F's I can get going? > but only F1-4 actually work) You can get sessions running on Alt-F[1-8], but the 'standard' /etc/inittab only runs getty/login on Alt-F[1-4]. You can start sessions on the other consoles by using 'doshell' or adding lines to /etc/inittab. > 4 pty's (are these the consoles F1-4?) No, those are 'pseudo' ttys, which programs like MGR use to simulate tty connections. That's probably a gross over-simplification, but it gives you the general idea, I think. :) > p_init: lp1 exists (0) (is that the (l)ine (p)rinter?) Right. VII.23) What is the meaning of files ended by .T.Z (or .taz) ? ANSWER: The suffix Z is for compressed files (to uncompress them use the command `uncompress file.Z`). The suffix T indicates a "tar file" the usual suffix is tar but, the 14 chars filename limit of the Minix filesystem makes it cumbersome to use .tar.Z (to untar a file ended by .T, use the command `tar options file.T` (see the man page for more details). For the .taz file, change them as .T.Z and go-ahead. VII.24) What is the meaning of files ended by .T.z (or .tpz) ? ANSWER: The suffix z is for files compressed with the gzip utility, which is being used more frequently because it provides better compression. These can be uncompressed with the `gzip -d file.z` command. VII.25) I have upgraded the kernel from XX to YY (XX > YY), however the login screen still says YY. ANSWER: Just change the message in one of these files: /etc/issue and /etc/motd. The former contains the message before the login, the later is the one after you are logged in. VII.26) What is doshell good for ? ANSWER: It's an old program provided in the early Linux version (0.12) when the getty was not already there, it spawns a shell on any tty's. (Mattew Gream): I do this quite often ( getty on tty1, 2, 3 and my rc.local spawns a shell on tty4 as follows '/usr/bin/doshell /dev/tty4 /bin/tcsh &' VII.27) I don't have the kernel sources, how can I change the keyboard language? ANSWER: You can use the fixkbd program written by Laurent JULLIARD (Laurent_JULLIARD@grenoble.hp.com). Its purpose is to fix the keyboard map used in your kernel image. It works more or less a la "rootdev" (or rdev). It can be found on tsx-11.mit.edu in /pub/linux/binaries/sbin/fixkbd.tar.Z. VII.28) Does there exist a possibility to track down the source of kernel pannic messages ? ANSWER: Here's info from Linus on how to track down the source of kernel panic messages. The values for EIP, address, and so on are JUST EXAMPLES: the EIP, EFLAGS, etc. can be anything. The lines after ">" were written by me; the responses by Linus. > Unable to handle kernel paging request at address C000000A This means something in the kernel tried to access kernel memory at address 0x00A (the C0000000 offset is due to the kernel starting at virtual address 0xC0000000). The first page of kernel address space is unmapped to find these kinds of incorrect references (it's probably a NULL dereference to a structure member at offset 0xA). > Oops: 0002 Error code. This tells you if it's a read or write (forget which ritgh now, and don't have any books handy) > EIP: 0008:000290D2 This is where it happened: segment 0008 (kernel code segment) and offset 0x290D2 into the kernel. So to find this, you generally do something like nm /usr/src/linux/tools/system | sort | less and search for the function that contains the address 0x290D2. > EFLAGS: 00010087 > fs: 0017 Eflags and fs when the exception happened. You usually don't need this. > base: C0000000, limit: 000A0000 > Pid: 0, process nr: 0 In what process the exception happened. This is the swapper, which also means the thing is fatal (other processes you can just kill). That it's in the swapper process probably means that it's an interrupt that did it, as the swapper doesn't really do anything. > 89 50 04 c7 03 00 00 00 00 c7 This is the instruction that resulted in the error. I usually disassemble them by hand and see what it is, then I try to find out exactly where in the function this assembly sequence comes up (probably by compiling the .c file to a .s file and looking around). Alternatively you can just run 'gdb' on /usr/src/linux/tools/system, but gdb has some problems. > task[0] (swapper) killed: unable to recover > kernel panic: Trying to free up swapper memory space > In swapper task - not syncing This is just to tell you not to expect anything from the kernel any more: linux cannot go on without the swapper task. > How can I decode the numbers in the message? > Also, note that sometimes the "Unable to handle..." > message is followed by the "Oops: 0002" block, but > the last message is sometimes something else (i.e. not > always a "task[0] (swapper)...." message, but something > from the TCP driver in this case. It depends on where it happened. If it's an interrupt, it can essentially happen in any task (all interrupts are handled in the task that happens to be currently active), while "normal" code happens in the task that calls it. ===================8<==========>8================ -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # LaBRI | # # 351 cours de la Liberation | e-mail: corsini@geocub.greco-prog.fr # # 33405 Talence Cedex | e-mail: corsini@labri.u-bordeaux.fr # # | # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -- There will be a sig when our local net is reliable. For now, I would rather stay anonymous.