Linux-Development-Sys Digest #691, Volume #7 Tue, 21 Mar 00 02:13:16 EST
Contents:
ioremap, insmod fails to resolve it ("Robert Karlsson")
Re: /dev/ttyS0 RTS/CTS problems (Ron)
Re: /dev/ttyS0 RTS/CTS problems (Ron)
LinuxWaves.com relaunched! (Kelechi Odu)
Directory File Space Reclaim (Weiguang Shi)
no action in my pants!! ("Dan Miller")
tutorials on tty interface?? ("Dan Miller")
Gonna build a computer... (Patrick Hagerty)
Re: Gonna build a computer... (Kaz Kylheku)
Re: tutorials on tty interface?? (Kaz Kylheku)
VFAT inode numbers change on remount (Daniel Dorau)
Re: Directory File Space Reclaim (Juergen Heinzl)
Re: kernelmessage ... and now? (Grahame M. Kelly)
Re: no action in my pants!! (Andy Guibert)
Re: Gonna build a computer... (Patrick Hagerty)
Re: File System Development ([EMAIL PROTECTED])
[embedded linux] where to get related information? ("tasi")
Re: Gonna build a computer... (Krzysztof Strasburger)
----------------------------------------------------------------------------
From: "Robert Karlsson" <[EMAIL PROTECTED]>
Subject: ioremap, insmod fails to resolve it
Date: Mon, 20 Mar 2000 17:21:11 GMT
Hi,
Following the advice given in my last post, i.e. using ioremap before
remap_page_range when mapping ISA device memory into user space.
I now end up with insmod telling me that it has failed to resolve the symbol
ioremap.
Is my kernel (2.2.5-15) to old or is it just not compiled properly.
Any hints?
Thanks,
/Robert
------------------------------
From: Ron <[EMAIL PROTECTED]>
Subject: Re: /dev/ttyS0 RTS/CTS problems
Date: Mon, 20 Mar 2000 13:02:41 -0500
Mats,
I had the same problem. I don't know the conventional wisdom for this,
but I solved it by disabling RTS/CTS flow control, changing the device
file to non-blocking mode, and then closing the device file.
I also restore the original termios structure. If you want to do that
also, then do it this way: restore everything in termios except force
RTS/CTS flow control to be disabled. Change to non-blocking mode and
then close the device file. If the original termios had RTS/CTS
enabled, then reopen the device file in a non-blocking mode, enable
RTS/CTS, and close the device file.
If you want a copy of my source code, let me know and I'll email it.
You can contact me at [EMAIL PROTECTED]
Ron from Michigan
Mats Byggmastar wrote:
>
> Hello folks,
>
> I'm working on some serial port code and have problems using
> the RTS/CTS flow control. Opening, sending and receiving data
> works fine but closing the port is problematic.
>
> I have two machines, connected using COM1 (/dev/ttyS0)
> running my program. Both programs are started and data is
> sent and received. Then one of the programs closes it's
> COM port. Now, when the other program tries to close it's
> port, it just hangs on the close() call. It hangs until
> the other program opens it's port again. It seems that close()
> is waiting for a pin to go high until it returns. This is
> strange as I open the port in nonblocking mode.
>
> Is my setup code (attached below) bad or can there be some other
> problems? The code is based on the "Serial Programming Guide for
> POSIX Operating Systems". I am using Red Hat 6.1
>
> Mats
------------------------------
From: Ron <[EMAIL PROTECTED]>
Subject: Re: /dev/ttyS0 RTS/CTS problems
Date: Mon, 20 Mar 2000 13:03:07 -0500
Mats,
I had the same problem. I don't know the conventional wisdom for this,
but I solved it by disabling RTS/CTS flow control, changing the device
file to non-blocking mode, and then closing the device file.
I also restore the original termios structure. If you want to do that
also, then do it this way: restore everything in termios except force
RTS/CTS flow control to be disabled. Change to non-blocking mode and
then close the device file. If the original termios had RTS/CTS
enabled, then reopen the device file in a non-blocking mode, enable
RTS/CTS, and close the device file.
If you want a copy of my source code, let me know and I'll email it.
You can contact me at [EMAIL PROTECTED]
Ron from Michigan
Mats Byggmastar wrote:
>
> Hello folks,
>
> I'm working on some serial port code and have problems using
> the RTS/CTS flow control. Opening, sending and receiving data
> works fine but closing the port is problematic.
>
> I have two machines, connected using COM1 (/dev/ttyS0)
> running my program. Both programs are started and data is
> sent and received. Then one of the programs closes it's
> COM port. Now, when the other program tries to close it's
> port, it just hangs on the close() call. It hangs until
> the other program opens it's port again. It seems that close()
> is waiting for a pin to go high until it returns. This is
> strange as I open the port in nonblocking mode.
>
> Is my setup code (attached below) bad or can there be some other
> problems? The code is based on the "Serial Programming Guide for
> POSIX Operating Systems". I am using Red Hat 6.1
>
> Mats
------------------------------
From: Kelechi Odu <[EMAIL PROTECTED]>
Subject: LinuxWaves.com relaunched!
Date: Mon, 20 Mar 2000 20:44:27 +0100
Hi all,
I wish to announce that LinuxWaves.com (http://www.linuxwaves.com) has
been relaunched. Bugs have been fixed and browser problems solved.
LinuxWaves.com is a new Linux Portal that features among other things;
� A Linux Bookstore
� Banner Exchange for Linux Sites
� FREE email
� Download links
� Linux links Directory
� Community Forum etc etc.
Visit LinuxWaves.com at http://www.linuxwaves.com and have a lot of
fun...
Kelechi Odu
http://www.linuxwaves.com
------------------------------
From: Weiguang Shi <[EMAIL PROTECTED]>
Subject: Directory File Space Reclaim
Date: Mon, 20 Mar 2000 13:06:38 -0700
Hi, there:
As I am reading the filesystem code of 2.0.38, it occurs to me that
the file systems (minix and ext2) do not reclaim the directory entries.
When an entry is deleted, the inode number is set to 0. This is
simple and efficient. But what if there is a directory with hundreds of
thounds of entries at a time gets all the files under it removed? This
will leave the directory file un-shrinked and thus wastes disk space.
Could someone point out I am right or wrong?
Thanks a lot.
Weiguang
------------------------------
From: "Dan Miller" <[EMAIL PROTECTED]>
Subject: no action in my pants!!
Date: Mon, 20 Mar 2000 12:16:45 -0800
Okay, now that I have your attention!! 8-{)
I was looking at conradp's pants script, at
http://www.cse.unsw.edu.au/~conradp/scripts/pants.html
and wanted to try it out on my Linux 2.0.36 system (it perports to require
kernel 2.2...). The only thing missing, I think, as a program called
"action",
which is called from several places. A typical call is:
action "" /bin/false
Is this a Linux 2.2 function?? I don't have any such thing in my
distribution.
What operations should this perform??
Thanks for any assistance on this obviously application-critical situation!!
Dan Miller
------------------------------
From: "Dan Miller" <[EMAIL PROTECTED]>
Subject: tutorials on tty interface??
Date: Mon, 20 Mar 2000 13:47:46 -0800
I have to implement a device driver for a custom PCI card which has (in
addition to a bunch of other stuff) a 16550 on it. We may have variable
numbers of these cards installed in any given system, so the number of
available serial ports will vary, and have to be established at runtime.
I've been looking at the code in tty_io.c et al, and there's so much there
that I'm not familiar with.
Are there any tutorials around which discuss the internals of these tty
modules, how they interact with hardware, how I tell the system how many
ports are available, what a 'line discipline' is and whether I need it,
etc?? I could use some guidance here. I've worked with Rubini's book a
fair bit, but the tty interface is sort of a different world than standard
drivers.
Thanks for any help you can give!!
Dan Miller
------------------------------
From: Patrick Hagerty <[EMAIL PROTECTED]>
Subject: Gonna build a computer...
Date: Mon, 20 Mar 2000 21:49:02 GMT
Greeting and salutatations to one and all.
I'm in the planning stages of setting up a PC exclusively for Linux. I
tried once before to convert an old Windows 98 machine over to Linux but
ran into problems stemming from the lack of available drivers for sound
and video.
I want to make sure the components I get, while as near to leading edge
technology as I can get, will have readily available and thoroughly
debugged drivers. I'm going to build this machine from the ground up
specifically to run full-blown Linux.
So, who can tell me what they consider the best sound card and video
card for a Linux system?
Are there any specific concerns or considerations I should be aware of?
I welcome any and all comments and suggestions from those who have been
there before me.
Thanks,
Patrick L. Hagerty
Hagware Software Services
http://www.hagware.com/
[EMAIL PROTECTED]
------------------------------
From: [EMAIL PROTECTED] (Kaz Kylheku)
Subject: Re: Gonna build a computer...
Reply-To: [EMAIL PROTECTED]
Date: Mon, 20 Mar 2000 23:04:58 GMT
On Mon, 20 Mar 2000 21:49:02 GMT, Patrick Hagerty <[EMAIL PROTECTED]> wrote:
>Greeting and salutatations to one and all.
>
>I'm in the planning stages of setting up a PC exclusively for Linux. I
How boring. The subject line enticed me into reading your article suggested
to me that you were doing something more than *assembling* a PC.
--
#exclude <windows.h>
------------------------------
From: [EMAIL PROTECTED] (Kaz Kylheku)
Subject: Re: tutorials on tty interface??
Reply-To: [EMAIL PROTECTED]
Date: Mon, 20 Mar 2000 23:15:15 GMT
On Mon, 20 Mar 2000 13:47:46 -0800, Dan Miller <[EMAIL PROTECTED]> wrote:
>Are there any tutorials around which discuss the internals of these tty
>modules, how they interact with hardware, how I tell the system how many
>ports are available, what a 'line discipline' is and whether I need it,
>etc?? I could use some guidance here. I've worked with Rubini's book a
>fair bit, but the tty interface is sort of a different world than standard
>drivers.
I've written a line discipline, so I may be able to answer the odd question.
You probably don't need to write one of these, unless there is a requirement to
create a custom datalink protocol in addition to a driver for the hardware (and
this datalink protocol must be in the kernel for some good reason).
Line disciplines are device independent: they should be capable of running over
top of any tty driver. Before I was ready for the real hardware, I was able to
test at least parts of the line discipline functionality by communicating with
it via the console by typing and cutting and pasting into it.
It sounds like you just need to write a driver for the hardware. Given that it
uses standard UART chips, you may be able to get away with hacking the existing
driver.
Your driver could grab a major number, and use minor numbers to identify
the boards. You tell the system how many board there are by failing to open
on minor numbers that correspond to nonexistent boards. So the application
can simply loop over the /dev/funkySerial* (or whatever you want to call them)
devices and try opening them in turn.
Another option is to have an ioctl that returns that number (i.e. you open one
board, and then ask it how many more there are), or to publish it in the /proc
filesystem somewhere.
--
#exclude <windows.h>
------------------------------
From: Daniel Dorau <[EMAIL PROTECTED]>
Subject: VFAT inode numbers change on remount
Date: 19 Mar 2000 21:57:24 GMT
Hello there,
I have a problem with the VFAT driver. My system has an ext2 and
a vfat partition. The problem is that the inode numbers of files
on the vfat partition change on each (re)mount of the vfat
partition.
This is irritating tar's incremental backup (-g) and makes
incremental backups of my vfat partition nearly impossible.
Does anybody know who's responsible for this driver and where
how to contact him? I tried to contact Gordon Chaffee
([EMAIL PROTECTED]) but did not receive any response.
--
Daniel Dorau [EMAIL PROTECTED]
<< Linux is like living in a tipi: No windows, no gates, Apache inside >>
PGP key available, send mail with 'Subject: send pgp key'
fingerprint: 8D7E0B2F9E2E5338 DB7B24742E8B2EAE
------------------------------
From: [EMAIL PROTECTED] (Juergen Heinzl)
Subject: Re: Directory File Space Reclaim
Date: Mon, 20 Mar 2000 23:35:43 GMT
In article <[EMAIL PROTECTED]>,
Weiguang Shi wrote:
>Hi, there:
> As I am reading the filesystem code of 2.0.38, it occurs to me that
>the file systems (minix and ext2) do not reclaim the directory entries.
> When an entry is deleted, the inode number is set to 0. This is
>simple and efficient. But what if there is a directory with hundreds of
>thounds of entries at a time gets all the files under it removed? This
>will leave the directory file un-shrinked and thus wastes disk space.
> Could someone point out I am right or wrong?
You are right, this is common to Unices, but *lo and behold* there is a
solution so step down from the window-sill again ...
mkdir somewhere
mv somewhereelse/* somewhere
rmdir somewhereelse
mv somewhere somewhereelse
... minor note, yes, with lots of creations and deletions the search
time can degrade as directories grow and minor note two, do not touch
lost+found directories as they need to have a certain size at least.
Cheers,
Juergen
--
\ Real name : J�rgen Heinzl \ no flames /
\ EMail Private : [EMAIL PROTECTED] \ send money instead /
------------------------------
From: [EMAIL PROTECTED] (Grahame M. Kelly)
Subject: Re: kernelmessage ... and now?
Date: 21 Mar 2000 01:00:19 GMT
In article <[EMAIL PROTECTED]>,
Daniel Schulze <[EMAIL PROTECTED]> writes:
> Ooops, seems to be an english list...
>
> Hi Folks
>
> following problem:
> I put a second 64MB bar into my pc and then...
> Early on booting the kernel (SuSE 2.2.13) says the following and stops
> working:
>
> Memory: 127680k/131072k (1240k kernel, 412k reserved, 1676k data, 64k
> init, 0k big)
> kmem-alloc: Bad slab magic (corrupt) name=kmem_cache
> canot create uid taskcount SLAB cache
>
> What wants he to tell me?!
> With mem-option <= 64MB everything works fine and the BIOS believes to
> have 128MB.
> What is the kernel doing at this time an why does he fail?
>
> (System: MoBo: NMC 5VMMC Rev1.0, K6-II-500, 64MB RAM (100MHz), 64MB
> (133MHz), ATI@Work AGP, SuSE6.3)
>
Daniel.
I think maybe that either your got the wrong type of simm (new 64Mb) or
it is possibly faulty. What i think it is saying is the new upper 64Mb
is probably faulty || your motherboard doesn't support >64Mb caching.
If its a questionable upper 64Mb simm swap the lower and upper simms
around and reboot - If its runs <64Mb OK but still has problem with
upper 64Mb then its your motherboard (you'll need a newer one maybe)
or your need to check out your BIOS configuration possibly,
if it fails then the new 64Mb module you got is faulty (or wrong type).
Well my 2c worth.
Cheers, Grahame
--
SLUG (Sydney Linux User Group) www.slug.org.au
------------------------------
From: Andy Guibert <[EMAIL PROTECTED]>
Subject: Re: no action in my pants!!
Date: Mon, 20 Mar 2000 21:12:24 -0500
Dan Miller wrote:
> I was looking at conradp's pants script, at
> http://www.cse.unsw.edu.au/~conradp/scripts/pants.html
Funny... :)
> and wanted to try it out on my Linux 2.0.36 system (it perports to require
> kernel 2.2...). The only thing missing, I think, as a program called
> "action",
> which is called from several places. A typical call is:
> action "" /bin/false
/bin/false does nothing, unsuccessfully.
> Is this a Linux 2.2 function?? I don't have any such thing in my
> distribution.
It wouldn't be a Linux 2.2 function as it's not part of the kernel. I've never
seen anything like it in RedHat and Debian so I'm assuming it's something this
conradp guy made (input, anyone?).
> What operations should this perform??
One can only assume nothing. What exactly would the pantsd do? Make sure your
Linux boxen keep their pants on? I didn't know Linux had such a problem, but
thanks for poiting that out... :)
> Thanks for any assistance on this obviously application-critical situation!!
BTW, this is a development group. Wouldn't comp.os.linux.misc be a more
appropriate place for your post?
Andy
=================================================
Remove the "nojunk" from my addy when responding.
"May the source be with you, Luke."
------------------------------
From: Patrick Hagerty <[EMAIL PROTECTED]>
Subject: Re: Gonna build a computer...
Date: Tue, 21 Mar 2000 03:12:01 GMT
Thank you for your very helpful comments.
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: File System Development
Date: Tue, 21 Mar 2000 03:49:02 GMT
Alan Donovan <[EMAIL PROTECTED]> wrote:
> > 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.
>
> First question: why?
>
> You say you are "required" to: is this for didactic reasons (you are a
> systems research student?) or because your company needs one? The
> answer to this question will make a substantial difference to the
> to yours: if you are a student, I recommend Minix. If not, why not use
> ext2: it's well tested, and that is surely important. Unless there is
> some other purpose to your desire to reinvent the wheel that you are
> not telling us...
Heh, no I am not a masochist nor am I crazy. It is a project for my OS
class in which I must create a filesystem not unlike IBM's JFS. I have
looked at the ext2 source, but it's big and ugly. Minix is certainly
much simpler, but it's a little difficult to read because of sparse
inline comments. It would be okay though if I could find some decent
documentation, hence my original message.
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
From: "tasi" <[EMAIL PROTECTED]>
Subject: [embedded linux] where to get related information?
Date: 21 Mar 2000 05:36:09 GMT
Dear All
I look for a embedded linux base on x86 or ARM target.
Could somebody tell me the success story about
(1) what target(Evaluate board) does you use? price? how to get the
information?
(2) where to get the embedded linux ?
Thanks!!
mail to [EMAIL PROTECTED]
------------------------------
From: Krzysztof Strasburger <[EMAIL PROTECTED]>
Subject: Re: Gonna build a computer...
Date: 21 Mar 2000 06:14:36 GMT
Patrick Hagerty <[EMAIL PROTECTED]> wrote:
>
>I'm in the planning stages of setting up a PC exclusively for Linux. I
>tried once before to convert an old Windows 98 machine over to Linux but
>ran into problems stemming from the lack of available drivers for sound
>and video.
Please read the linux hardware compatibility HOWTO. It is available
on many sites. See for example
http://metalab.unc.edu/mdw/HOWTO/Hardware-HOWTO.html
Krzysztof
------------------------------
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End of Linux-Development-System Digest
******************************
