Subject: Linux-Development Digest #568 From: Digestifier To: Linux-Development@senator-bedfellow.MIT.EDU Reply-To: Linux-Development@senator-bedfellow.MIT.EDU Date: Mon, 21 Mar 94 00:13:04 EST Linux-Development Digest #568, Volume #1 Mon, 21 Mar 94 00:13:04 EST Contents: SLIP_DISC? (Daniel S. Ridge) Re: Future development of Linux and affects on other architectures (Matt Welsh) Re: needs /usr/lib/libl.a (Yonik Seeley) Re: Future development of Linux and affects on other architectures (Larry Doolittle) Re: Mapping the text screen into user space (i.e. KDMAPDISP, mmap, etc) (Jim McGrath) OWEN LEBLANC (LeBlanc@mcc.ac.uk) CONTACT ME (Liem Bahneman) Serial: getty_ps backspace patch not good? (Arnoud Martens) Re: TTY overruns cost money. (Rob Janssen) ircII2.2.9 Problems (Paul Gray) Problems building OPS5 under CLISP (Andrew F Gunnesch) Re: TTY Overrun During Disk Access (Mark Lord) Re: [Q] Unixware filesystem? (Rob Janssen) Linux and NEC Versa Notebook (Darryl Burke - ACPS/F93) Re: ircII2.2.9 Problems (case) ---------------------------------------------------------------------------- From: newt@eng.umd.edu (Daniel S. Ridge) Subject: SLIP_DISC? Date: 20 Mar 1994 18:00:13 GMT Concerning SLIP (and dip) Here's the background: I would like to run SLIP over telnet. (ie, telnet from a dialup annex to a SLIP server running linux) and the SLIP server I have put together seems to hang the pty's when I run a dip -i. This is bad, because this machine is meant to serve as a SLIP server for several people. The sympton is that I can no longer telnet into the box. When I try, it gives me a quick normal-looking prompt and then closes the connection. Wehn it does this, I have to go to the building where the box is, and kill the dip from the console. Ugly. Now, I have tried killing the slip interface and the route to it, and that doesn't help. I am thinking it has something to do with setting the line discipline. Does this sound reasonable? More importantly, is there a way I can modify dip to not do this? (For this installation, running SLPI over term isn't an option... the server is a five meg machine running off of a floppy... is this something with the kernel, or the net2 stuff, or with dip? Thanks... newt@eng.umd.edu ------------------------------ From: mdw@cs.cornell.edu (Matt Welsh) Subject: Re: Future development of Linux and affects on other architectures Date: Sun, 20 Mar 1994 18:31:49 GMT In article eric@tantalus.nrl.navy.mil (Eric Youngdale) writes: > If we get ports to multiple architectures, this type of coding could be >quite difficult to read. Instead I would suggest that the macros or inline >functions be stored in the header files in include/asm. I agree, something along these lines is a good way to go. I'd like to see the Linux kernel abstracted somehwat for porting to other architectures; at the very least, moving assembly code out of the source proper. (Although there are many algorithmic things that are tuned to the x86). In theory, then, to port the heart of the kernel to another architecture you would only need to rewrite the `far back end' routines (task management, etc.) for that architecture. Of course, there are many other problems associated with that: For one thing, the core data structures would change across the board (such as task_struct) and interrupt handling would be greatly different. Then you're faced with the problem of porting device drivers to the new hardware. This is not an easy task for ANY kernel; most popular commercial UNIXes (SunOS, etc.) are tailored to a particular platform. I don't want to see the Linux kernel be abstracted to the point where it's no longer optimized for the x86. However, some of the code can be organized to (attempt to) separate the machine dependencies from the abstract algorithms. Unfortunately x86 assumptions run throughout the kernel, and abstracting those any further would undoubtedly complicate things considerably. ------------------------------ From: yseeley@Xenon.Stanford.EDU (Yonik Seeley) Crossposted-To: comp.os.linux.help Subject: Re: needs /usr/lib/libl.a Date: 20 Mar 1994 21:13:25 GMT In article <1994Mar20.032852.3059@cs.brown.edu>, Wen-Chun Ni wrote: >In article kjchang@hpl.hp.com (K. J. Chang) writes: >>I need to compile (gcc) a program with option "-ll" (two l's, >>like long). Therefore, I need a file called "libl.a". I found >>it in /usr/lib in my commercial UNIX workstations. >> >>Where can I find libl.a ? >> > >No, you can't. Under non-commercial *nix like Linux, you should use >flex instead of lex. So check /usr/lib/libfl.a. If still nonexistent, >ftp the flex source from GNU site. > I put in symbolic link /usr/lib/libl.a -> /usr/lib/libfl.a This is preferable to modifying makefiles, especially if you are working on something for many OS's. Maybe this link should be added into new distributions? You may also need to add the -l flag to provide maximum compatability with lex. Do a man on "flex" or "flexdoc" for more information. Another Idea: How about a lex script containing "/usr/bin/flex -l $*" instead of a symbolic link? - Yonik Seeley > >-- >Wen-Chun Ni, wcn@cs.brown.edu >------------------------------------------------------------------- > "Great spirits have always encountered violent opposition > from mediocre minds..." -- Albert Einstein ------------------------------ From: doolitt@cebaf4.cebaf.gov (Larry Doolittle) Subject: Re: Future development of Linux and affects on other architectures Reply-To: doolitt@cebaf4.cebaf.gov (Larry Doolittle) Date: Wed, 16 Mar 1994 14:25:13 GMT In article <2m58s2$86q@bmerha64.bnr.ca>, Hamish.Macdonald@bnr.ca (Hamish Macdonald) writes: > I'd just like to mention here that anyone who is developing new > features in Linux, or is enhancing existing features to add new > functionality should keep in mind that Linux is being ported to other > architectures. I agree fully. > Any time you feel the urge to put inline assembler into code which has > no direct link to either the i386 architecture or the IBM PC clone > architecture, think twice before doing so. > If you absolute must put in inline assembler (speed reasons are the > only possible reason I can see), please abstract it out into an Speed concerns are real! Not everyone has a Pentium, remember. > "inline function" or a preprocessor macro, and keep the definition of > the inline function or macro separate from the main functionality. ... When you do, it should take the form: #ifndef i386 simple { c; substitute(); } #else high speed assembly hack #endif A good example is in linux/drivers/sound/audio, except they chose to use #ifdef NO_INLINE_ASM instead of #ifndef i386. I would like to see the fast file name compares in the file system directories pulled out into a construct like this, and since they all do about the same thing, it can go into a common asm/ include. > If you follow rules like this, then it makes porting of these new > features to Linux on other architectures easier. Personally, I don't have any grand hopes that "Linux" will become a mainstream OS for anything other than x86 machines. OTOH, the code base it has generated (and is continuing to generate) is real, and will have a lasting effect on *nix for all machines. > An example of the benefits of this is the fact that the "net/unix" > Unix domain socket code ported over to Linux/68k with absolutely no > changes required to the source. I was very happy when I was able to > do this. Yahoo! I am looking forward to a Linux-ish R4200 laptop. - Larry Doolittle doolittle@cebaf.gov ------------------------------ From: jim@stove.actrix.gen.nz (Jim McGrath) Subject: Re: Mapping the text screen into user space (i.e. KDMAPDISP, mmap, etc) Date: Mon, 21 Mar 1994 11:06:55 GMT Mahesh Neelakanta (mahesh@sendai.seq.com) wrote: : sometimes the program doesn't write anything to the screen at all. This : is reproducible especially when the cursor is at the bottom of the screen. : For some reason, if I switch to another vt and then swap back before running : the program, this problem goes away.. The Linux vt code moves the start of the screen forward in the display buffer to do scrolling. This gives a limited scrollback buffer if you need it. You are mmapping an area ofthe diplay memory that wil not be visible if there has been any scrolling. Shift pgup/pgdn I think, to scroll. However, switching vts clears this buffer and the display is reset to 0xb8000 again. Thus your code works again. Jim ------------------------------ From: roland@cac.washington.edu (Liem Bahneman) Crossposted-To: comp.os.linux.admin,comp.os.linux.help Subject: OWEN LEBLANC (LeBlanc@mcc.ac.uk) CONTACT ME Date: 20 Mar 1994 19:43:20 GMT Owen LeBlanc, of MCC please contact me, this is regarding the upgrade of MCC. Your email seems to bounce at LBlanc@mcc.ac.uk: Subject: Returned mail: Insufficient permission ----- Transcript of session follows ----- mail: cannot append to /usr/mail/zlsiial mail: cannot create dead.letter 550 ... Insufficient permission Email me at roland@cac.washington.edu Please! - liem bahneman -- ===[roland@cac.washington.edu]========================[The Last Gunslinger]=== Outside of a dog, computers are a man's best | UCS Consulting friend, inside a dog it's too dark to type. | UW Ice Hockey/X-Phile http://topquark.cecer.army.mil/~roland/ | Linux/WWW/tcl/tk/LOTRmush ------------------------------ From: arnoud@ijssel.hacktic.nl (Arnoud Martens) Subject: Serial: getty_ps backspace patch not good? Date: Sun, 20 Mar 1994 21:38:17 GMT Reply-To: arnoudm@ijssel.hacktic.nl Hi I got the backspace patch for getty_ps2.0.7c from sunsite, The patch basically outputs two backspaces on the tty instead of one when type the backspace key. It seems a stupid hack to me and moreover, after applying the patch the charcters still aren't erased, very annoying if you are a bad typist ;-). So I looked at the terminal setting that getty uses to open the line. It sets the tty-line to non-canonical mode, ignoring the flags in gettydefs on this matter. I fail to see the reason for this and after I set the line back to canonical mode (either using stty or modifying the code) the backspace key works as expected: it deletes one character from the buffer and from the screen. Could somebody explain me why getty opens the line using with the ICANON flag disabled (this happens in funcs.c line 268)? And why is the backspace not echoed when the line is in non-canonical mode ? Gtx: -- Arnoud Martens Delft, the Netherlands +31(0)15-563621/572701 arnoudm@ijssel.hacktic.nl ------------------------------ From: rob@pe1chl.ampr.org (Rob Janssen) Subject: Re: TTY overruns cost money. Date: Sun, 20 Mar 1994 23:02:43 GMT Reply-To: pe1chl@rabo.nl In <1994Mar15.025603.3796@void.tdcnet.nl> nemosoft@void.tdcnet.nl (Nemosoft Unv.) writes: >In article tgm@netcom.com (Thomas G. McWilliams) writes: >>Kai Petzke (wpp@marie.physik.tu-berlin.de) wrote: >>: However, if overruns happen on every single move with the mouse, >>: there should be something wrong with the kernel. >> >>The more likely problem is that the mouse was given a higher >>priority interrupt than the modem. The modem should always be >>given interrupt 3 if possible--this is naturally the case if you >>use /dev/cua1 for your modem. >Pardon ?? All interrupts are handled at the same priority... There's no such >thing as a precedence for modems on certain serial ports... I'm afraid your >confusing interrupts with i386 microcode priviledge levels, or something. Not true. Please read the i8259 (interrupt controller) manual >Anyway, my questions still stand: why is now all this attention payed to >some vague bit that tells me something is overrunning, while I obviously >loose no data, and why am I even bothered by them at 2400 baud ? That's >ridiculous. I've never seen any MS-DOS comm-program bitch about overruns, >not even at extreme high speeds like 115200 baud on an 8088 XT. And then I >didn't loose a single byte ! But it wasn't using interrupts. And you could not run something else besides it. >However, I credit you in 1 thing: support to share COMports on IRQs. But >even there things are weird. For example: my mouse for X is on ttyS6 (1200 >buad) (COM7 *cheer*), using IRQ3. So is my modem at ttyS3 (2400 baud). Now >these combinations work or don't: >kermit on /dev/cua3, 2400 baud, 8N1 : mouse hangs. >uucico dial out on /dev/cua3, 2400 baud, 8N1 : mouse rolls happily >DIP on /dev/cua3, 2400 baud, 8N1 : DIP input gets eaten a bit >uugetty on /dev/cua3, 2400 baud, 8N1 : mouse hangs. >Now you find the differences, and tell me what's wrong. Note that the only >point where mouse & modem "meet" is in /linux/drivers/char/serial.c where >the interrupt handlers are. Even something simple as opening the device from >kermit will hang the mouse, then I'm not even 'c'onnected to it.... Shared interrupts only work when the hardware allows it. So you must use a multiport card which can share interrupts. Jumpering several card's to the same interrupt won't work. This is a PC hardware limitation, which cannot be solved in software. >*seriously considers of throwing out this cereal.c and start from scratch* I advise you to first do some study before you think you can do better that this. The quoted article contains several misconceptions. Rob -- ========================================================================= | Rob Janssen | AMPRnet: rob@pe1chl.ampr.org | | e-mail: pe1chl@rabo.nl | AX.25 BBS: PE1CHL@PI8UTR.#UTR.NLD.EU | ========================================================================= ------------------------------ From: pgray@saucer.cc.umr.edu (Paul Gray) Subject: ircII2.2.9 Problems Date: Sun, 20 Mar 1994 23:28:37 GMT I am having problems compiling IRCII2.2.9 on my linux. I am using slackware distribution, linux vers 0.99.15. I have already changed LEX = FLEX lexlib = So its not those common problems. I get an undefined symbol error. (yywrap undefined symbol) Its in count.c, which is the first file it tries to compile so maybe something is just set wrong. Does anyone have any ideas? -PJ -- ===================================================================== Paul J. Gray pgray@umr.edu University of Missouri-Rolla ------------------------------ From: afgun@engin.umich.edu (Andrew F Gunnesch) Subject: Problems building OPS5 under CLISP Date: 21 Mar 1994 00:10:10 GMT Hello there. I got CMU's OPS5 implementation, and have tried unsuccessfully to build it under Bruno Haible's CLISP. Has anybody got a running OPS5 for some LIPS under Linux? --andrew ------------------------------ From: mlord@bnr.ca (Mark Lord) Subject: Re: TTY Overrun During Disk Access Date: 21 Mar 1994 00:05:47 GMT In article <1994Mar20.214154.20323@seas.smu.edu> mustafa@seas.smu.edu writes: >In article , >Kai Petzke >wrote about tty overruns occurring under ``heavy load''. > >I noticed a similar problem even under ``normal load'', i.e. >Are disk accesses supposed to inhibit ``received data ready'' interrupts >from the 16450? I thought disk accesses in modern PC's would make use of DMA >(direct memory access) and would not take up processor cycles, although >they would take up bus cycles while the data is being written to disk. The IDE interfaces on virtually all (except some rare new systems) systems do not include DMA hardware support. Neither do most IDE drives themselves. The linux IDE driver (hd.c) completely blocks all interrupts during data xfers. This will change Real Soon Now, after my patches soak for another week. If you want to try them out, look for the << IDE Performance Package >> patch posted last week to comp.os.linux.development. Cheers, -ml -- mlord@bnr.ca Mark Lord BNR Ottawa,Canada 613-763-7482 ------------------------------ From: rob@pe1chl.ampr.org (Rob Janssen) Subject: Re: [Q] Unixware filesystem? Date: Sun, 20 Mar 1994 23:17:17 GMT Reply-To: pe1chl@rabo.nl In johnsonm@ladybird.oit.unc.edu (Michael K. Johnson) writes: >In article hpa@ahab.eecs.nwu.edu (H. Peter Anvin N9ITP) writes: > In article <2m25ee$iv4@cville-srv.wam.umd.edu> of comp.os.linux.development, > barspi@wam.umd.edu (Barzilai Spinak) writes: > > After 1 1/2 years of waiting, I will shortly have a BIG computer and > > will install Unixware, Linux and Windows (ugh! ...I need to). My question > > is if there's a Unixware filesystem the Linux can use. I don't know anything > > about Unixware yet and I don't know if it uses a proprietary filesystem > > or not. > Unixware probably uses either UFS or the SysV filesystem. Linux > supports the SysV filesystem; it does not support UFS. >Unixware, by default, uses the Veritas filesystem, which is a >log-structured filesystem with extremely good crash recovery. I have >only once ever seen a veritas filesystem come up so much as dirty >after a crash, and that once, a simple fsck didn't even have to do any >corrections to the filesystem -- just marked it clean. And I have >seen plenty of hard crashes on unixware machines running veritas -- >device driver development... When we got a machine with that filesystem, we thought "let's see how that performs". Made a filesystem and mounted it under /mnt Then: (cd /usr/lib/terminfo; tar cf -) | (cd /mnt; tar xvf -) When it was happily copying the files: break the power. Result: the filesystem was "recovered" but there were several 0-sized copied files near the point where the copy was when the power dropped. Ok, the output filesystem was not corrupted, but it certainly was not in a consistent state. (I would have expected those 0-sized files to simply have vanished, as their data was not written ok) Less-demanding tests gave better results, and it was still considered a good thing. Rob -- ========================================================================= | Rob Janssen | AMPRnet: rob@pe1chl.ampr.org | | e-mail: pe1chl@rabo.nl | AX.25 BBS: PE1CHL@PI8UTR.#UTR.NLD.EU | ========================================================================= ------------------------------ From: dburke@acs.ryerson.ca (Darryl Burke - ACPS/F93) Subject: Linux and NEC Versa Notebook Date: 21 Mar 1994 01:08:08 GMT Has anyone tried to get linux to run on a NEC Versa yet, i can get the base system to work fine, but "X" will complain about the vga card type... any suggestion?? maby the mono server or the VGA16 server???? Darryl Burke dburke@turing.acs.ryerson.ca ------------------------------ From: case@gamera.syr.edu (case) Subject: Re: ircII2.2.9 Problems Date: Mon, 21 Mar 1994 02:00:15 GMT Paul Gray (pgray@saucer.cc.umr.edu) wrote: : I am having problems compiling IRCII2.2.9 on my linux. I am using : slackware distribution, linux vers 0.99.15. : I have already changed LEX = FLEX : lexlib = : So its not those common problems. I get an undefined symbol error. : (yywrap undefined symbol) Its in count.c, which is the first file it : tries to compile so maybe something is just set wrong. Does anyone have : any ideas? It still might be that common problem... it should read LEX = flex LEXLIB = -lfl That should fix you problem. If not there is a bin release at undernet.org in something like /pub/undernet/Clients, but thats from memory. Still not that hard to find. Good Luck. -=-Case ------------------------------ ** FOR YOUR REFERENCE ** The service address, to which questions about the list itself and requests to be added to or deleted from it should be directed, is: Internet: Linux-Development-Request@NEWS-DIGESTS.MIT.EDU You can send mail to the entire list (and comp.os.linux.development) via: Internet: Linux-Development@NEWS-DIGESTS.MIT.EDU Linux may be obtained via one of these FTP sites: nic.funet.fi pub/OS/Linux tsx-11.mit.edu pub/linux sunsite.unc.edu pub/Linux End of Linux-Development Digest ******************************