Linux-Development-Sys Digest #370, Volume #8 Fri, 22 Dec 00 14:13:13 EST
Contents:
Re: Problems with Linux kernel? (mitch@foo)
Re: Problems with Linux kernel? (Erik de Castro Lopo)
Intel 815 sound problem (Amit Purohit)
libc vs glibc and posix ([EMAIL PROTECTED])
[I need some nice tutorial for the IEEE1394 device driver] ("�Ǽ�ȣ")
Re: Make drivers myself ([EMAIL PROTECTED])
HOWTO access SCSI devices from custom modules ? ([EMAIL PROTECTED])
Re: RPC: Connection Refused ([EMAIL PROTECTED])
Re: Problems with Linux kernel? ([EMAIL PROTECTED])
Re: HOWTO access SCSI devices from custom modules ? (Alain-Pierre CHERTIER)
Howto access kernel memory from user application ? ([EMAIL PROTECTED])
Re: Char device drivers and mknod (Petric Frank)
Looking for device driver references for Linux 2.2 kernel. ("M Boerner")
Re: Howto access kernel memory from user application ? ([EMAIL PROTECTED])
Re: RPC: Connection Refused ([EMAIL PROTECTED])
Re: Howto access kernel memory from user application ? (Josef Moellers)
Re: Howto access kernel memory from user application ? ([EMAIL PROTECTED])
Re: libc vs glibc and posix ([EMAIL PROTECTED])
[OT]Re: Problems with Linux kernel? ("Arthur H. Gold")
Re: [OT]Re: Problems with Linux kernel? (Philip Armstrong)
----------------------------------------------------------------------------
From: mitch@foo <[EMAIL PROTECTED]>
Subject: Re: Problems with Linux kernel?
Date: 21 Dec 2000 21:30:05 -0800
In article <OsA06.85260$[EMAIL PROTECTED]>, "Joshua says...
>
>I want to hear peoples' voices and opinions about what programmers do and
>don't like about the Linux kernel. All feedback will be integrated into the
>design of yet another Open Source operating system.
Is this a joke?
instead of re-inventing the wheel one more time, why don't
you spend the effort to improve what is allready here?
------------------------------
From: Erik de Castro Lopo <[EMAIL PROTECTED]>
Subject: Re: Problems with Linux kernel?
Date: Fri, 22 Dec 2000 06:45:22 GMT
mitch@foo wrote:
>
> In article <OsA06.85260$[EMAIL PROTECTED]>, "Joshua says...
> >
> >I want to hear peoples' voices and opinions about what programmers do and
> >don't like about the Linux kernel. All feedback will be integrated into the
> >design of yet another Open Source operating system.
>
> Is this a joke?
>
> instead of re-inventing the wheel one more time, why don't
> you spend the effort to improve what is allready here?
I think you missed the point. Here's a translation:
"I want to write a operating system kernel but can't think of
a simngle good reason to do so. Can You?"
Erik
--
+-------------------------------------------------+
Erik de Castro Lopo [EMAIL PROTECTED]
+-------------------------------------------------+
"He's a born-again Christian. The trouble is, he suffered brain
damage during rebirth."
------------------------------
From: Amit Purohit <[EMAIL PROTECTED]>
Subject: Intel 815 sound problem
Date: Fri, 22 Dec 2000 13:08:37 +0000
Hi,
I am having an intel 815 chipset. The sound for the same is not
working properly.
I have alsa driver installed. It plays the sound but too fast . Do anyone
have idea ?
Thanx,
Amit
------------------------------
From: [EMAIL PROTECTED]
Subject: libc vs glibc and posix
Date: Fri, 22 Dec 2000 07:28:47 GMT
I have been looking all over for this answer, but i am out of luck.
from a programmers perspective, what is the difference between libc5 and
glibc? for ionstance, what type of code coould i compile under glibc
that i couldn't under libc5? the only thing that i could find was some
headers (errno.h) had to be explicitly called, and that signals are more
BSD than SRV. are there anyu other differences, or does anybody know
any docs which explain the differences?
thank you....
Sent via Deja.com
http://www.deja.com/
------------------------------
From: "�Ǽ�ȣ" <[EMAIL PROTECTED]>
Subject: [I need some nice tutorial for the IEEE1394 device driver]
Date: Fri, 22 Dec 2000 18:21:54 +0900
Hi, everybody.
I want to know some nice guide for the IEEE1394 device driver.
I need to know how to program a device driver for IEEE 1394 devices.
Please, let me know....
Merry Christmas... Bye.
------------------------------
From: [EMAIL PROTECTED]
Reply-to: [EMAIL PROTECTED]
Subject: Re: Make drivers myself
Date: Fri, 22 Dec 2000 10:54:00 GMT
>>>>> "chemarey" == chemarey <[EMAIL PROTECTED]> writes:
chemarey> I would like to know how to make drivers for some hardware,
chemarey> for example a keyboard, a special mouse etc.
That would be suggestive of these being "character" devices, as
opposed to "block" devices [generally associated with disk drives and
occasionally network devices].
You should start by availing yourself of the existing source code,
which contains more than a few examples of drivers for keyboards and
mice.
The book "Linux Device Drivers" by Rubini is reputedly pretty good.
You might also avail yourself of the KernelWiki, once it "rises from
the ashes." <http://kernelbook.sourceforge.net/wiki/?KernelWiki>
Kernel HOWTO
<http://www.ibiblio.org/pub/Linux/docs/HOWTO/Kernel-HOWTO>
--
(reverse (concatenate 'string "ac.notelrac.teneerf@" "454aa"))
<http://www.ntlug.org/~cbbrowne/>
"Not only do I strongly recommend against using PC NFS, but I'm
willing to bet you won't find anyone willing to code a free PC NFS
client. I bet even Richard Stallman would charge for a PC NFS
client." -- Steve Conley <[EMAIL PROTECTED]>
------------------------------
From: [EMAIL PROTECTED]
Crossposted-To: comp.periphs.scsi
Subject: HOWTO access SCSI devices from custom modules ?
Date: Fri, 22 Dec 2000 10:46:25 GMT
Environment: Redhat Linux 7.0 (kernel 2.2.16-22smp)
===================================================
Hi guys!
I'd like to send SCSI-2 commands to specific SCSI devices
from a kernel module. My queries are:
how do I get to SCSI devices from my custom module ?
do I need to use the "open" system call from my module ?
Thanking in anticipation.
Regards,
-energon
Sent via Deja.com
http://www.deja.com/
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: RPC: Connection Refused
Date: Fri, 22 Dec 2000 12:42:09 GMT
Is the portmap server running on the target system?
[EMAIL PROTECTED] wrote:
> My place of emplyment, someone has devloped a SCSIserver for SGI, SUN,
> and LInux. He used rpc for this. This server program works find on one
> linux box. But when I installed it on a new linux box, I get this when I
> use a client: Connection Refused. I am able to connect fine on the
> other linux box. I am unable to find any rpc.hosts kind of file any on
> the new linux host. What do I need to do on the new linux box to accept
> RPC calls?
> thanks
> Enrique Herrera
> [EMAIL PROTECTED]
> Sent via Deja.com
> http://www.deja.com/
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: Problems with Linux kernel?
Date: Fri, 22 Dec 2000 12:46:01 GMT
Joshua Schaeffer <[EMAIL PROTECTED]> wrote:
> I want to hear peoples' voices and opinions about what programmers do and
> don't like about the Linux kernel. All feedback will be integrated into the
> design of yet another Open Source operating system.
> To avoid flooding this newsgroup with non-relevant postings, please send any
> remarks to the following e-mail address:
> [EMAIL PROTECTED]
> Many thanks in advance for your responses!
FWIW, I think a major shortcoming of the Linux kernel (at least the Redhat one)
is that I find it very difficult to use it without running into that damn
command prompt thing. And it is broken for very many of the DOS commands that
I am used to using. Even with the new windowing modules, such as gnome, (
which I think is an excellent kernel feature), you still need to use the
command prompt to do just about anything.
:)
------------------------------
From: Alain-Pierre CHERTIER <[EMAIL PROTECTED]>
Crossposted-To: comp.periphs.scsi
Subject: Re: HOWTO access SCSI devices from custom modules ?
Date: Fri, 22 Dec 2000 12:37:43 GMT
Hello.
Normally you can't directly use standard i/o C language lib functions
inside device driver (?) modules => you can't make open/read/write
standard calls.
You should try ioctls by the low level way to pass through the
/dev/sg generic SCSI services or issue direct ioctls to the
scsi device driver controlling the wanted scsi physical device.
At 1st level, consult the SCSI programming HOWTO manual which
gives a complete example of identifying scsi devices
on the scsi bus (this is through /dev/sg generic device interface
in user mode).
Programming modules often needs to manage kernel mode constraints
which is not as easy as programming in normal user mode...
Don't hesitate to email Linux community programmers who have
involved in developping the linux scsi services. One person
who always answers to our requests is Alan Cox who can indicate
right contacts when he (rarely) doesn't know the answer himself !
;-)
Alain-Pierre CHERTIER <[EMAIL PROTECTED]>
Sent via Deja.com
http://www.deja.com/
------------------------------
From: [EMAIL PROTECTED]
Subject: Howto access kernel memory from user application ?
Date: Fri, 22 Dec 2000 14:13:33 GMT
Hi all,
>From a user application, I try to modify the value of a symbol exported
by a kernel module.
I call query_module (module name, which = QM_SYMBOLS, ...). I get the
address of the symbol I want to modify = 0xc805246c ; it's exactly the
address found for this symbol in /proc/ksyms.
But when I try to read its content (in gdb), I get the message :
can't access memory at address 0xc805246c.
How could I manipulate this kernel symbol in a user application ?
Thanks for help,
Sylvie
Sent via Deja.com
http://www.deja.com/
------------------------------
From: Petric Frank <[EMAIL PROTECTED]>
Subject: Re: Char device drivers and mknod
Date: Fri, 22 Dec 2000 15:40:03 +0100
Hello David,
David Wragg schrieb:
>
> Petric Frank <[EMAIL PROTECTED]> writes:
> > I am interested on the reason not to do this (mknod in device drivers).
> > Actually i can not understand why i should not code it into the driver.
>
> Kernel code takes up unpageable memory. Is there any reason why you
> can't do a "mknod" in a script to be run when the driver is installed,
> perhaps even in the driver's Makefile?
2 Reasons:
1. The driver gets the major device number at load time from the kernel
(when registering it via register_chrdev). So at installation time the
major device number is not known.
2. Resulting from above and assuming that the driver is loaded
automatically (entered in /etc/modules.conf): The entry in /dev must be
generated automatically at load time of the character device driver.
Remember: i'm at kernel 2.2.x (not 2.4.x - there is no devfs).
Therefore i am asking for a 'mknod' source, because the functions in
glibc (the function is mknod) are not callable by a device driver.
(okok, i may analyze the glibc source to get the code, but if someone
has a code snippet for me it will be much easier).
> David Wragg
regards
Petric
------------------------------
From: "M Boerner" <[EMAIL PROTECTED]>
Subject: Looking for device driver references for Linux 2.2 kernel.
Date: Fri, 22 Dec 2000 09:29:00 -0600
Hi:
I must be looking in the wrong places, but I am looking for reference
material on the differences between the 2.0 and 2.2 kernels for device
drivers.
Thanks in advance.
Michael
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: Howto access kernel memory from user application ?
Date: Fri, 22 Dec 2000 20:45:36 +0500
> How could I manipulate this kernel symbol in a user application ?
>
See kernel functions:
get_user(...) /* receive data from user */
put_user(...) /* transmit data to user */
--
+----------------------+
| Andrey V. Valik |
| Papillon Systems |
|Mailto:[EMAIL PROTECTED]|
+----------------------+
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: RPC: Connection Refused
Date: Fri, 22 Dec 2000 16:14:07 GMT
Yes. I do have portmap running..
/sbin/chkconfig --list | grep port
portmap 0:off 1:off 2:off 3:on 4:on 5:on 6:off
ps aux | grep port
rpc 382 0.0 0.3 1468 504 ? S Dec21 0:00 portmap
In article <B_H06.10452$[EMAIL PROTECTED]>,
[EMAIL PROTECTED] wrote:
>
> Is the portmap server running on the target system?
>
> [EMAIL PROTECTED] wrote:
>
> > My place of emplyment, someone has devloped a SCSIserver for SGI,
SUN,
> > and LInux. He used rpc for this. This server program works find on
one
> > linux box. But when I installed it on a new linux box, I get this
when I
> > use a client: Connection Refused. I am able to connect fine on the
> > other linux box. I am unable to find any rpc.hosts kind of file any
on
> > the new linux host. What do I need to do on the new linux box to
accept
> > RPC calls?
>
> > thanks
>
> > Enrique Herrera
> > [EMAIL PROTECTED]
>
> > Sent via Deja.com
> > http://www.deja.com/
>
Sent via Deja.com
http://www.deja.com/
------------------------------
From: Josef Moellers <[EMAIL PROTECTED]>
Subject: Re: Howto access kernel memory from user application ?
Date: Fri, 22 Dec 2000 17:32:21 +0100
[EMAIL PROTECTED] wrote:
> =
> Hi all,
> From a user application, I try to modify the value of a symbol exported=
> by a kernel module.
> I call query_module (module name, which =3D QM_SYMBOLS, ...). I get the=
> address of the symbol I want to modify =3D 0xc805246c ; it's exactly th=
e
> address found for this symbol in /proc/ksyms.
> But when I try to read its content (in gdb), I get the message :
> can't access memory at address 0xc805246c.
> =
> How could I manipulate this kernel symbol in a user application ?
fd =3D open(/dev/kmem, O_RDWR);
lseek(fd, addr, SEEK_SET);
read(fd, &buf, size);
or
write(fd, &buf, size);
What do you mean by "using gdb to read kernel memory?
HTH,
Josef
-- =
Josef M=F6llers (Pinguinpfleger bei FSC)
If failure had no penalty success would not be a prize (T. Pratchett)
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: Howto access kernel memory from user application ?
Date: Fri, 22 Dec 2000 21:50:44 +0500
[EMAIL PROTECTED] wrote:
>
> > How could I manipulate this kernel symbol in a user application ?
> >
>
> See kernel functions:
>
> get_user(...) /* receive data from user */
> put_user(...) /* transmit data to user */
>
If you don't want write driver, you can try use
/dev/mem for physical memory access
/dev/kmem for kernel virtual memory access
--
+----------------------+
| Andrey V. Valik |
| Papillon Systems |
|Mailto:[EMAIL PROTECTED]|
+----------------------+
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: libc vs glibc and posix
Date: Fri, 22 Dec 2000 22:50:23 +0500
[EMAIL PROTECTED] wrote:
>
> I have been looking all over for this answer, but i am out of luck.
> from a programmers perspective, what is the difference between libc5 and
> glibc? for ionstance, what type of code coould i compile under glibc
> that i couldn't under libc5? the only thing that i could find was some
> headers (errno.h) had to be explicitly called, and that signals are more
> BSD than SRV. are there anyu other differences, or does anybody know
> any docs which explain the differences?
>
> thank you....
>
> Sent via Deja.com
> http://www.deja.com/
Struct packing:
under libc5 - packed (you can use fpack-struct in Makefile to pack your structs)
under glibc - not packed (you can't use fpack-struct in Makefile and you must
use #pragma pack(1) to pack your structs)
Also you can see changes by this command (if you want)
for i in `ls /usr/doc/glibc-2.1.2/Change*`;do less $i;done
--
+----------------------+
| Andrey V. Valik |
| Papillon Systems |
|Mailto:[EMAIL PROTECTED]|
+----------------------+
------------------------------
Date: Fri, 22 Dec 2000 12:32:34 -0600
From: "Arthur H. Gold" <[EMAIL PROTECTED]>
Subject: [OT]Re: Problems with Linux kernel?
[EMAIL PROTECTED] wrote:
>
> Joshua Schaeffer <[EMAIL PROTECTED]> wrote:
> > I want to hear peoples' voices and opinions about what programmers do and
> > don't like about the Linux kernel. All feedback will be integrated into the
> > design of yet another Open Source operating system.
>
> > To avoid flooding this newsgroup with non-relevant postings, please send any
> > remarks to the following e-mail address:
> > [EMAIL PROTECTED]
>
> > Many thanks in advance for your responses!
>
> FWIW, I think a major shortcoming of the Linux kernel (at least the Redhat one)
> is that I find it very difficult to use it without running into that damn
> command prompt thing. And it is broken for very many of the DOS commands that
> I am used to using. Even with the new windowing modules, such as gnome, (
> which I think is an excellent kernel feature), you still need to use the
> command prompt to do just about anything.
>
> :)
I think you misunderstand what's actually _in_ the kernel.
The kernel comprises the lowest level of software -- the
part that interacts directly with the underlying hardware,
and provides for system calls (with which one generally
interfaces using the system libraries). That's all.
Everything else you mention is merely user-space code (like
whatever shell you're using, the windowing system,
whatever). Unless you're programming _very_ low level code,
you never interact with the kernel directly.
What you're essentially saying is, "I understand Windoze.
This isn't Windoze. I don't understand it. Therefore I don't
like it."
One of the things that DOS, Windows and the MacOs (up to
MacOS 9) did was conflate the notions of the operating
system and its user interface (in the long run to their
detriment. Many of the problems Windows and the MacOS have
had in terms of scaling to modern machines and their usage
has been the fact that the various levels of their "OS"s are
so intertwined).
I would recommend going to www.linux.org, or some comparable
website to better understand how the various pieces fit
together.
HTH,
--ag
--
Artie Gold, Austin, TX (finger the cs.utexas.edu account
for more info)
mailto:[EMAIL PROTECTED] or mailto:[EMAIL PROTECTED]
--
A: Yes I would. But not enough to put it out.
------------------------------
From: [EMAIL PROTECTED] (Philip Armstrong)
Subject: Re: [OT]Re: Problems with Linux kernel?
Date: 22 Dec 2000 18:51:15 -0000
In article <[EMAIL PROTECTED]>, Arthur H. Gold <[EMAIL PROTECTED]> wrote:
>[EMAIL PROTECTED] wrote:
>> Joshua Schaeffer <[EMAIL PROTECTED]> wrote:
>> > I want to hear peoples' voices and opinions about what programmers do and
>> > don't like about the Linux kernel. All feedback will be integrated into the
>> > design of yet another Open Source operating system.
>>
>> > To avoid flooding this newsgroup with non-relevant postings, please send any
>> > remarks to the following e-mail address:
>> > [EMAIL PROTECTED]
>>
>> > Many thanks in advance for your responses!
>>
>> FWIW, I think a major shortcoming of the Linux kernel (at least the Redhat one)
>> is that I find it very difficult to use it without running into that damn
>> command prompt thing. And it is broken for very many of the DOS commands that
>> I am used to using. Even with the new windowing modules, such as gnome, (
>> which I think is an excellent kernel feature), you still need to use the
>> command prompt to do just about anything.
>>
>> :)
>I think you misunderstand what's actually _in_ the kernel.
>The kernel comprises the lowest level of software -- the
>part that interacts directly with the underlying hardware,
>and provides for system calls (with which one generally
>interfaces using the system libraries). That's all.
>Everything else you mention is merely user-space code (like
>whatever shell you're using, the windowing system,
>whatever). Unless you're programming _very_ low level code,
>you never interact with the kernel directly.
And I think you've just been had, hook line and sinker :)
Note the smiley at the end of the post to which you replied...
Phil
--
http://www.kantaka.co.uk/ .oOo. public key: http://www.kantaka.co.uk/gpg.txt
------------------------------
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