Linux-Development-Sys Digest #688, Volume #7 Sun, 19 Mar 00 18:13:18 EST
Contents:
Re: MP3 Players Other Than Rio (Christopher Browne)
Re: kernel in C++ (Christopher Browne)
File System Development ([EMAIL PROTECTED])
Device Driver Developer Opportunity-Telecommute (Brian)
Re: How to test a device driver (Pjtg0707)
Re: NIC's promisc mode (Robert Prowel)
Re: ramdisk: releasing memory (Peter Pointner)
Re: Rubini's device driver example (Christian Winter)
Xserver problem ("Dimitry Katkov")
sharing DMAable memory (Mirko Saam)
Re: Rubini's device driver example ("Roger J. Pryor")
Re: NIC's promisc mode (Robert Redelmeier)
sock_sendmsg() (James Emil Avery)
tricky code in super.c (Weiguang Shi)
Re: sock_sendmsg() (David Wragg)
Re: Bootdisks, rdev, and root filesystems...aargh! ("Dennis Heltzel")
how to write/read sector to hd? ([EMAIL PROTECTED])
GNU C compiler source code (Qui Nguyen)
----------------------------------------------------------------------------
From: [EMAIL PROTECTED] (Christopher Browne)
Crossposted-To: comp.os.linux.hardware
Subject: Re: MP3 Players Other Than Rio
Reply-To: [EMAIL PROTECTED]
Date: Sat, 18 Mar 2000 23:23:40 GMT
Centuries ago, Nostradamus foresaw a time when Nix would say:
>[EMAIL PROTECTED] (Christopher Browne) writes:
>
>> product that appears somewhat Europe-oriented. (What's 230 Euro in
>> USD?)
>
>Last I heard, approximately $200. ;)
Which isn't too dramatically-awful a price.
There's another relevant product: the I-Jam. It comes with two
16MB CompactFlash cards, and appears to treat them as filesystems.
16MB means about 15 minutes, so you're left swapping 'em every few
minutes, but that's solvable by bigger Flash cards.
At present, it appears that the USB CompactFlash reader isn't yet
supported on Linux, but Matthew Dharm is apparently working on it.
--
(eq? 'truth 'beauty) ; to avoid unassigned-var error, since compiled code
; will pick up previous value to var set!-ed,
; the unassigned object.
-- from BBN-CL's cl-parser.scm
[EMAIL PROTECTED] - - <http://www.hex.net/~cbbrowne/hardware.html>
------------------------------
From: [EMAIL PROTECTED] (Christopher Browne)
Subject: Re: kernel in C++
Reply-To: [EMAIL PROTECTED]
Date: Sat, 18 Mar 2000 23:25:56 GMT
Centuries ago, Nostradamus foresaw a time when Nix would say:
>[EMAIL PROTECTED] (Alexander Viro) writes:
>> Leave filesystems alone. Contrary to luserish faith, OOP can be done in
>> C just fine and it's _much_ better to have clean langauge with
>> well-understood semantics for doing that stuff. C++ is too messy for
>> that. It tries too hard to look like C and that harms it.
>
>OK, well, then I have a cool acronym:
>
>SCUFS, the Scheme Unified File System.
>
>Now I just need to write the code ;)
There's already PODFUK, which essentially does this in Perl, allowing
the gentle user to create NFS servers.
SCUFS would be an interesting idea...
--
There are two kinds of people in the world: People who think there are
two kinds of people and people who don't.
[EMAIL PROTECTED] - - <http://www.hex.net/~cbbrowne/scheme.html>
------------------------------
From: [EMAIL PROTECTED]
Subject: File System Development
Date: Sun, 19 Mar 2000 00:00:42 GMT
Hi,
I am required to develop a file system, possibly based on ext2 or
minix. Can someone point me to some good documentation related to
this? I am mostly concerned with implementation details rather than
high-level aspects of the VFS (which I already know).
Thanks for your help.
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
From: Brian <[EMAIL PROTECTED]>
Subject: Device Driver Developer Opportunity-Telecommute
Date: Sun, 19 Mar 2000 00:15:55 GMT
I have an immediate position opening with my client for a
DEVICE DRIVER DEVELOPER.
You can work from your own home.
This is an exceptional opportunity.
If you have previous experience writing device drivers in any of the
following categories, please contact me immediately.
Audio Device Drivers (WDM preferred)
2D or 3D Video Device Driver Experience (Windows, or Linux, or Unix)
Network Device Drivers (Windows, or Vxworks, or Unix, or ATM,
or NDIS, or bluetooth, or Sonet/SDH)
RTOS Embedded Systems Experience (x86, or Hitachi, or SH3, or MIPS)
You have nothing to loose and everything to gain.
My client is a well-established very respected company in the industry.
This is a full time position, with salary and complete company
benefits.
I will be more than happy to give you details, if you contact me.
All information and correspondence will be kept strictly confidential.
==============================
Contact me for more details.
Mailto:[EMAIL PROTECTED]
==============================
------------------------------
From: [EMAIL PROTECTED] (Pjtg0707)
Subject: Re: How to test a device driver
Reply-To: [EMAIL PROTECTED]
Date: Sun, 19 Mar 2000 00:56:37 GMT
On Fri, 17 Mar 2000 15:40:04 +0000, Alan Donovan <[EMAIL PROTECTED]>
wrote:
>I don't wish to point out the obvious, but I fell into this trap: the
>samples from the ORA website are for pre 2.1 kernels, but they contain a
>directory called v2.1 which has the updated code in. You need to compile
>this, as the old stuff won't work any more.
I've been trying out the snull codes in v2.1 directory, and I am still
having problems with it after patching some codes. For one thing,
the system kept complaining about dev_tint . Is there a major diff between
2.1 and 2.2.x that I can read up on? I am running RH 6.0.i
also, has insmod changed between 2.1 and 2.2.x kernels?
------------------------------
From: [EMAIL PROTECTED] (Robert Prowel)
Subject: Re: NIC's promisc mode
Date: 19 Mar 2000 07:41:38 GMT
On 18 Mar 2000 16:42:34 +0000, Nix <$}xinix{[email protected]> wrote:
>[EMAIL PROTECTED] (WiseGuy) writes:
>
>> But then, what legitimate uses are there for promisc mode anyway?
>
>Debugging network protocols?
>
>Finding problems with network cabling?
I've always been under the impression that TCP/IP didn't need to be
debugged since it's been around for like 15+ years and is a very well thought
out suite of protocols. Problems with network cabling can be found with
well defined system utilities like traceroute and ping. Anyway, why reinvent
the wheel? There are commercial sniffer products available that can save
and analyze packet data. Anytime someone asks about a NIC cards promisc
mode I get a vision of some would be cracker using Linux to look for cleartext
passwords and the like. I don't mean to disparage the intellectual curiosity
of any computer science students who are interested in exploiting the
capabilities of the technology but from a network and systems management
perspective it sends up warning flags in my mind.
I guess I'm just trying to live up to the image of a facist admin. :-)
------------------------------
From: Peter Pointner <[EMAIL PROTECTED]>
Subject: Re: ramdisk: releasing memory
Date: 19 Mar 2000 09:43:06 +0100
Thomas Eschenbacher <[EMAIL PROTECTED]> wrote:
[snip]
> Is there any way to _really_ get rid of the memory used in the ramdisk?
[snip]
I thought the utility "freeramdisk" should do that?
Peter
------------------------------
From: Christian Winter <[EMAIL PROTECTED]>
Subject: Re: Rubini's device driver example
Date: Sun, 19 Mar 2000 01:57:49 +0100
Harish K Chandraia schrob:
> I am trying to run the first example in Rubini's Linux Device
> Drivers and when I run the insmod command, I don't see "Hello World"
> from the init_module() being printed and I don't see anything from
> the cleanup_module() being printed when I run the rmmod command
> either.
Are you running X? printk's don't appear on an X console.
Switch to a standard console and try from there.
HTH
Christian
--
|~-_ /~~~~~ Free Linux Portal: http://www.linux-config.de ~~~~~\ _-~|
| // de.etc.schreiben.* - Usenet-Literatur im www: \\ |
| // http://www.usenet-autoren.de \\ |
|_||[EMAIL PROTECTED]http://www.thepoet1.de__||_|
------------------------------
From: "Dimitry Katkov" <[EMAIL PROTECTED]>
Subject: Xserver problem
Date: Sun, 19 Mar 2000 15:19:22 +0200
Hi All.
I am trying to run LEM (Linux - embedded) and the problem raised when I am
trying to 'startx'. It tells me
'Fatal server error:
could not open default font 'fixed'
Does anybody know if the LEM Xserver works?
Can anybody recommend some good book about X?
Thank you,
Dimitry.
------------------------------
From: Mirko Saam <[EMAIL PROTECTED]>
Subject: sharing DMAable memory
Date: 19 Mar 2000 14:07:09 GMT
hi!
i'm porting a chardev to a recent kernel version
and have the following problem:
the driver should allocate a dma-able piece of
memory (via ioctl) and return a pointer to the
caller. The caller must be able to read and write
this memory. The old code segment looks like:
pAdr = (unsigned long) kmalloc (size, GFP_DMA | GFP_BUFFER);
uAdr = do_mmap (file, 0, (size+~PAGE_MASK) & PAGE_MASK,
PROT_READ | PROT_WRITE, MAP_SHARED,
pAdr & PAGE_MASK);
return(uAdr);
This only produces a SEGV if the caller tries
to access the pointer (read or write). What's
the right way to this with 2.2.x kernels?
I've read Rubini's book and was not able to find
a working solution.
Please help me out here,
Mirko
------------------------------
From: "Roger J. Pryor" <[EMAIL PROTECTED]>
Subject: Re: Rubini's device driver example
Date: Sun, 19 Mar 2000 15:40:55 GMT
> Harish K Chandraia schrob:
> > I am trying to run the first example in Rubini's Linux Device
> > Drivers and when I run the insmod command, I don't see "Hello World"
> > from the init_module() being printed and I don't see anything from
> > the cleanup_module() being printed when I run the rmmod command
> > either.
>
> Are you running X? printk's don't appear on an X console.
> Switch to a standard console and try from there.
>
> HTH
> Christian
>
> --
> |~-_ /~~~~~ Free Linux Portal: http://www.linux-config.de ~~~~~\ _-~|
> | // de.etc.schreiben.* - Usenet-Literatur im www: \\ |
> | // http://www.usenet-autoren.de \\ |
> |_||[EMAIL PROTECTED]http://www.thepoet1.de__||_|
Or take a look into /var/log/messages, that is the printk daemon's log
file.
--
-----------------------------------------------------------------
Roger J. Pryor P. Eng. Email: [EMAIL PROTECTED]
Pryor and Pryor Inc. Telephone: (+1)(604) 685-2621
602 - 1230 Comox Street Fax: (+1)(604) 683-3488
Vancouver, B.C., Internet: http://www.pryor-and-pryor.com
V6E 1K7, Canada
------------------------------
From: Robert Redelmeier <[EMAIL PROTECTED]>
Subject: Re: NIC's promisc mode
Date: Sun, 19 Mar 2000 10:51:46 -0800
Nix wrote:
> [EMAIL PROTECTED] (WiseGuy) writes:
> > But then, what legitimate uses are there for promisc mode anyway?
> Debugging network protocols?
> Finding problems with network cabling?
The best one I can think of is debugging ugly problems like
two machines trying to use the same IP address.
The other legit purpose would be to monitor and classify network
traffic for network administration and expansion. You could
determine where switches would help [& where they wouldn't],
and what kind of traffic is eating up the bandwidth so you
could justify shutting down the Napster :)
-- Robert
------------------------------
From: James Emil Avery <[EMAIL PROTECTED]>
Subject: sock_sendmsg()
Date: Sun, 19 Mar 2000 18:51:48 +0100
Hi,
I'm trying to communicate with a userland process in a kernel module for
our IP masquerader.
Basically, what I want is to send two messages on a datagram Unix domain
socket which is bound to a userland process.
If I use sock->ops->send(), the machine crashes first thing when I try to
send a packet.
Using sock_sendmsg(), I get a strange behaviour: If I set the length
parameter of sock_sendmsg() to 0, a message is sent and registered on the
other end. If it is nonzero, an EFAULT (invalid address) is returned --
obviously not true, since the null-message comes through fine.
How is one supposed to use sockets from within the kernel?
I've distilled the problem into the following code:
-
s = sock_alloc();
sock_create(PF_LOCAL, SOCK_DGRAM, 0, &s) ;
serva.sun_family = AF_LOCAL;
memcpy(serva.sun_path, FORWARD_BIND_PATH, sizeof(FORWARD_BIND_PATH));
serva.sun_path[sizeof(FORWARD_BIND_PATH)] = 0;
if ((s->ops->connect(s,(struct sockaddr*)&serva,sizeof(serva),0))<0){
printk(KERN_INFO "Couldnt connect to %s\n",FORWARD_BIND_PATH);
return 1;
}
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iovlen = 1;
msg.msg_iov = vec;
vec[0].iov_base = &test;
vec[0].iov_len = 2;
if ((error = (sock_sendmsg(s,&msg,2)))<0)
printk(KERN_INFO "%d :((((\n", error);
else printk(KERN_INFO "OK?\n");
-
Now, the very same code using userland 'sendmsg' etc. works fine.
Thanks in advance for any help on the subject.
--
Med venlig hilsen,
James Avery <[EMAIL PROTECTED]>
------------------------------
From: Weiguang Shi <[EMAIL PROTECTED]>
Subject: tricky code in super.c
Date: Sun, 19 Mar 2000 12:41:38 -0700
Hi, there:
I am reading the code of /usr/src/linux/fs/super.c of version 2.0.38.
At line 443, there is "s = 0+super_blocks;". I don't know why this is the
way it is. Would a simple "s=super_blocks;" hurt?
Thanks.
Weiguang
------------------------------
From: David Wragg <[EMAIL PROTECTED]>
Subject: Re: sock_sendmsg()
Date: 19 Mar 2000 18:37:45 +0000
James Emil Avery <[EMAIL PROTECTED]> writes:
> Using sock_sendmsg(), I get a strange behaviour: If I set the length
> parameter of sock_sendmsg() to 0, a message is sent and registered on the
> other end. If it is nonzero, an EFAULT (invalid address) is returned --
> obviously not true, since the null-message comes through fine.
sock_sendmsg() expects the data to be in user-space. Becuase your data
is in kernel-space, the access checks fail, hence EFAULT. Empty
messages are an exception since they don't have any data.
To avoid this you need to do a set_fs(get_ds()) before the
sock_sendmessage(), and then restore fs afterwards. See other places
in the kernel that call sock_sendmsg (e.g. in net/sunrpc/) for
examples.
David Wragg
------------------------------
From: "Dennis Heltzel" <[EMAIL PROTECTED]>
Crossposted-To: alt.os.linux,comp.os.linux.misc
Subject: Re: Bootdisks, rdev, and root filesystems...aargh!
Date: 19 Mar 2000 22:09:20 GMT
You need to use a bootmanager like lilo or syslinux to uncompress the root
FS into a RAM
disk and then load the kernel into memory. I've used syslinux for this
quite successfully
(I know that RedHat uses it also, if that matters).
Don Werve <[EMAIL PROTECTED]> wrote in article
<[EMAIL PROTECTED]>...
> Anyways, I made a root filesystem that compressed takes up 900K, and
> have a 460K kernel. I used dd to copy the kernel image to the disk, and
> then used `rdev /dev/fd0 /dev/fd0 ; rdev -R /dev/fd0 0` to set the disk
> as it's own root device. How do you tell the kernel where to look for a
> compressed root filesystem, so that it can be uncompressed into a
> ramdisk and booted...?
------------------------------
From: [EMAIL PROTECTED]
Subject: how to write/read sector to hd?
Date: Sun, 19 Mar 2000 22:06:22 GMT
Hi,
I am desperately trying to find a very simple low level function that
writes and reads to any part of the hard drive.
I have a 2nd, empty, ext2 hard drive mounted to /db/ directory.
I am using gnu gcc and cannot use functions such as fopen because it is
not efficient enough. I need to use the entire hard disk as one big
binary; i.e., 50Gb of data.
I know how to do this in dos by simply calling the bios routine to
write or read at any sector on the hard drive, but I would much rather
stay
away from dos ;-)
Currently I am looking into the ll_rw_block() function but I have no
idea if this is the correct or proper function.
Thanks for the help in advanced!!
Paul_L
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
From: Qui Nguyen <[EMAIL PROTECTED]>
Subject: GNU C compiler source code
Date: Sun, 19 Mar 2000 23:28:01 +0100
Hi all,
I want to know whether GNU C compiler source code is free or not. If
it's free
where I can download it.
Thanks in advance
------------------------------
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End of Linux-Development-System Digest
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