Re: dd command (it was Call for a README)
X-Authentication-Warning: Consulate.UFP.CX: rhw owned process doing -bs Date: Mon, 6 Mar 2000 02:07:56 + (GMT) From: Riley Williams [EMAIL PROTECTED] X-Sender: [EMAIL PROTECTED] To: Juanjo Marin [EMAIL PROTECTED] Subject: Re: dd command (it was Call for a README) Hi Juanjo. There are two points that need considering: 1. Larger block sizes are indeed faster up to a point. However, all floppy disks used on ix86 have a sector size of 512 bytes, so anything larger than that is meaningless. Remember that the time to write to the floppy will swamp any savings from reading the kernel image in larger blocks from the hard drive. 2. Some implementations of the dd command have a bug that results in their ignoring the final block if it is not the full blocksize in length, and would produce faulty floppies if used. My comments therefore pointed out that... a. If the dd command is used to write the floppies, it is ESSENTIAL that the bs=1 parameter be specified UNLESS we can guarantee that the raw kernel image size will be a multiple of some larger number. The alternative would be to specify the size of the kernel image as the blocksize and treat it as one large block. However, in this application, there's unlikely to be any speed difference between the two simply because the floppy drive is so much slower... b. Because of the problem mentioned in (2) above, I would NOT recommend the use of the dd command in the install guide. I understand now what you say. Noting that the three commands are exactly equivalent as far as writing to floppy is concerned, I would recommedn the use of the `cp elks.img /dev/fd0` command for producing the floppies simply because doing so minimises the likelihood of producing a faulty floppy. I sounds more sensible... Matt what do you think about changing your INSTALL with this new process of creating the disks? or anybody knows a good reason for not changing it? My last question: it could be nicer/better to use conv=noerror,notrunc,sync ? I'm not sure what you are referring to here, sorry? These are options for the dd commands I read in the dd man page. Ah... conv=flags Convert the input according to one or more (comma-separated) flags listed below ... noerror = continue processing when erros occur (up to 5 in a row). Well, then I thin that this flag it's not useful for us :-). To be honest, it'd do more harm than good - if an error occurs on the boot floppy we're creating, we want to know about it... notrunc = Don't truncate output file Not really relevant when the output file is a device. sync = Pad input blocks to ibs If that ensures that the whole kernel image is written out, then yes, it would be useful. Well I this moment I think I am not quite sure if these flags are useful for our purposes or not. All this stuff is starting to be a bit of mess for me :-( I know the feeling, don't worry... Best wishes from Riley. * Copyright (C) 2000, Memory Alpha Systems. * All rights and wrongs reserved. +--+ | There is something frustrating about the quality and speed of Linux | | development, ie., the quality is too high and the speed is too high, | | in other words, I can implement this feature, but I bet someone | | else has already done so and is just about to release their patch. | +--+ * http://www.memalpha.cx/Linux/Kernel/ Juanjo Marín Becario Monitor del Programa de Formación de Personal de Apoyo a la Investigación y más allá teléfono: 954 55 10 17 email: [EMAIL PROTECTED] _/_/_/_/_/_/_/_/_/ _/ de _/ _/ _/_/ _/ _/_/_/ de _/ _/ _/ entro _/roceso _/atos _/ _/_/_/ _/_/_/_/_/ Universidad de Sevilla E S P A Ñ A / S P A I N / S P A N I A
Re: Is ELKS a good idea for teaching O.S.
I am a beginer with Minix and ELKS, but I prefered ELKS (not MINIX) first because Minixs' bad development. I actually mean that Minix's developers don't work so hard on Minix. At the first time, I asced Al about somethin, and I recived answers very fast, on Minix distribution I asked some questions so, and I don't get any answer, yet. That why I prefered ELKS. And Minix news group doesn't work on my news server:( At the mean time Minix is interesting too.. That is my prposition how to learn Unixs... You're right, the development of ELKS is much more live than Minix (Minix is considered finished or nearly finished). On the other hand, we don't have a book that explains ELKS internals by now. The Minix book is interesting anyway (The Minix filesystem, the one used by ELKS, is explained on that book and it can be used to learn OS concepts from a UNIX point of view as well). Because Minix has a book and ELKS doesn't, I said that Minix _could_ be better for teaching (you and your students have a reference book), but I think that ELKS is perfect for learning by your own (if you enjoy learning by code). ELKS is like the GPLed cousin of Minix and the small brother (or sister ???) of Linux :-), and all they belong to the big Unix family. :-) best regards, Juanjo
Re: Is ELKS a good idea for teaching O.S.
Iñaki, I am looking for a simple OS to use teaching (modifying the kernel) and despite simplicity is very important, I'd like to be possible to load pre-compiled programs and to have a file system in hard disk. I think that Minix may be a better option for teaching because there are books (well, 2 editions of one book) written for this purpose. The book is titled "Operating Systems: Design and Implementation". The author of the first Edition is A.S. Tanenbaum and the authors of the second one are A.S. Tanenbaum and A. S. Woodhull. The good point is that they have been translated into Spanish (I don't know if there is a Basque translation) The translation is called "Sistemas Operativos: Diseño e Implementación". Both editions are published by Prentice Hall. It's very likely that you can find copies of the 1st edition in the library of your CS faculty. The ISBN of the 2nd edition is 970-17-0165-8 Anyway, If you are very interested in ELKS, you can find some technical papers on the ELKS site. We (at least me!!!) would be very grateful if you wrote some essays that help people to learn how ELKS works. About Linux, there are some documents and books about the kernel. There is a translation of David Rusling's "The Linux Kernel" avalaible in any mirror of LuCAS (LinUx en CAStellano). And there is a translation of a French (or maybe English) book, called "Porgramación Linux 2.0", Editorial Gestión 2000, de Rémy Card, Eric Dumas and Franck Mével. Hope this help you, Greetings from Sevilla Juanjo
Re: RE: Call for a README (LEEME, the Spanish translation)
Here you are the Spanish translation of README, called LEEME Bye, Juanjo At 18:41 21/01/00 -0800, you wrote: : If you have any suggestions for this readme send your comments to : [EMAIL PROTECTED] : or : [EMAIL PROTECTED] : : --Phillip J Rhoades Fantastic job! You're definitely hired for a writing position!! Greg Thanks I've attached a copy with some correction to punctuation, spelling, etcetera. Anything else I can help with? *** Free voicemail and email, by phone or Web! Free phone calls too! Get it today at http://www.myTalk.com *** Attachment Converted: "c:\util\win\telefon\eudora.jj\attach\README.elks" LEEME
Re: Embedded and Real-time systems
At 15:00 7/10/99 +0100, you wrote:
I would therefore like some pointers to texts that would give me an answer
to the following questions:
What type of API is the application code going to use? Is the UNIX system
API any use at all?
What about POSIX 1003.1b and 1003.1c ? It's supposed to be useful for real
time systems. There is a POSIX draft, POSIX 1003.13 draft 9,(AFIK is still
a draft) where four profiles for real-time systems are defined:
PSE51 - Minimal real-time system profile
PSE52 - Real-time cntroller system profile
PSE53 - Dedicated real-time system profile
PSE54 - Multi-purpose real-time system profile
This is a brief summary of features of these profiles:
file-system multiple-proceses multiple-threads
PSE51 No NoYes
PSE52 Yes NoYes
PSE53 No Yes Yes
PSE54 Yes Yes Yes
I think that embedded world and Real Time world are very closed (fecuently
mixed), so you can find more information and "inspiration" if you read docs
from RT OSes, eg QNX is a good one to start from (very small and with
POSIX features). RTLinux (http://www.rtlinux.org/~rtlinux/) and RTAI are
the Linux approaches to RT and they are trying to be POSIX compliant
(http://www.fsmlabs.com/beta).
Minix world has some RT experiences. There is a porting FSU pthreads
library called Champollion
(http://atc.unex.es/jdiaz/anatome/contrib/champollion/champollion.html) and
a scheduler ("Implementing Real-Time services in MINIX" Wagner, G.; ACM
Operating Systems Review. July 1995).
I hope this helps you,
Juanjo
Misc
Hi I have this "simple" question: what does 'linuxmt' means (is the directory where the includes are :D ). Why not something like linux-elks, elks or whatever. I'm just curious I think that it would be a good idea to design a logo for the project (something better than just the name). I think that it would be nice to play with the name ELKS, and the logo could be an elk, maybe playing with an penguin or something. I've found a nice elk or moose picture on the web but the problem is that I don't know its copyright policy (As far I remember is in http://www.arrakis.es/~juanjo96/sooseani.gif). Another other pictures with are somewhere in the oreilly pages (www.oreilly.com/oreilly/poweredby/). bye, Juanjo
Re: ELKS on HP200LX
Hi there !!! I found this information from the web some time ago: ---cut- MINIX on the HP200LX by Dr. Richard L. Dubs (last updated: July 1, 1998) Summary I have developed PCMCIA and BIOS INT13 Hard Disk Services for the HP200LX that allow someone to boot MINIX from a PCMCIA ATA flash disk. MINIX is not stable yet on the 200LX, allowing you (at most) to login and type one command before it crashes. Nevertheless, I believe that by solving the PCMCIA problem, I have solved one of the hard parts of getting MINIX to run on the HP200LX, and I'm hoping that the Internet community will now help finish the job. The PCMCIA and BIOS services I have developed should be just as useful to boot and run LINUX-86 (ELKS) on the 200LX. The software I have developed is provided on my web page (www.erols.com/rld) for download. - I hope this would be helpful ! Juanjo At 19:16 28/04/99 -0300, you wrote: Well, I've tried to run ELKS on my palmtop and I don't know if I'm having success. I use Steffen Gabel's bootelks which needs a kernel image and a *clean* vector interrupt image. The kernel it's ok, I compiled it from last source. The problem is with the vector interrupt image, because I don't have how to make it. The bootelks uses a way to get this vii, writing a little program on sector 0 0 1 of a floppy disk. When you boot the system with this floppy disk, it gets a clean vii. The HP has DOS in ROM and I can't boot her from flash card or other device, so i can't have this image. I'm trying to make this image through my pentium but i guess that it's not working because when I run bootelks, it gives the following messages: BELOW! Loading interrupts image... Success. Loading kernel image... Success. then, if it doesn't crash, it reboots the system... Any idea ? .~. /V\ N[e]xt L[e]v[e]l // \\ Isaque Galdino /( )\ Programador C/C++, PL/SQL ^`~'^ Linux, DOS e Win... ops! :)
