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Anton Erasmus
*nix forums beginner
Joined: 23 Mar 2005
Posts: 27
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 Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: Programm is not running witout VGA
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On Tue, 1 Feb 2005 11:39:53 +0100, invalid-domain-see@sig.com wrote:
| Quote: | In article <ctnl43$s7p$00$1@news.t-online.com>,
"Nils Koehler" <nils.koehler@ibt-interfaces.de> writes:
We have a Linux 2.4 running on a Kontron Dimm-PC.
The system Software is not running properly, when we
let run it without a VGA graphic card module installed.
What do you mean by "System Software"? Linux Kernel, BIOS ?
Is there any Switch to ignore the Grafic card BIOS
You can configure Linux to use e.g. a serial port as console and
you can remove the VGA console driver from the kernel. That should
do the trick as far as Linux is concerned.
For the BIOS: most of them need a VGA card/Keyboard for the configuration
dialog, so setting up the board configuration (and fixing it if there
was, e.g. a CMOS checksum error ...) can only be done with a VGA card
installed. Most BIOSes, however have an option where you can select
wether a VGA/EGA card is "installed". I forget the names of the
proper selections to be made, but this usually allows you to put
the board into a mode where it will boot without a VGA.
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There is a VGA card emulator with a serial port available. You plug
this card into the PC, and it simulates enough of a VGA card to fool
the BIOS. All output to the console is then converted to a normal
RS-232 serial stream. I have forgotten the name of the company,
but it should be in the archives.
Regards
Anton Erasmus |
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VSS
*nix forums beginner
Joined: 19 Feb 2005
Posts: 1
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: IPC between tasks in kernel
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Hi Mark,
Thanks for the pointers.
Vividh
Mark H Johnson wrote:
| Quote: | VSS wrote:
Hi Guys,
My question was pertaining to tasks *inside* the kernel. What I really
want to do is this.
First - you don't have "tasks" in the kernel. You can have threads,
created by the kernel, that basically run within the kernel address space.
I have some callbacks which get called in the kernel.
What is the context that this callback function gets called [e.g.,
interrupt, with or without locks held, allowed to sleep, ...]?
Your solution will vary based on the context of the implementation.
I want to send a cook up a message and send it to the other task(B).
Task B just keeps waiting for these messages and handles the message.
Is it possible to do this?
Certainly.
Look at the interfaces that implement one of [from a recent 2.6 kernel] ...
- [ksoftirqd/#]
- [pdflush]
- [aio/#]
- [kjournald]
There are about two dozen of these kernel threads on my 2 CPU system.
Review how hey work / choose the method that matches your situation the
closest / implement the same interface. A quick grep...
# grep -ir pdflush /usr/src/linux-2.6.10/
gives a couple hundred hits including comments on a pool of worker
threads, structures for passing work to those threads, a list of
operations to perform, protection by locks, and so on. That certainly
covers all the bases but may be "too heavy" for your application.
--Mark
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E. Charters
*nix forums Guru Wannabe
Joined: 20 Feb 2005
Posts: 156
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: Student looking for re-readers for his thesis ( it deals with embedded system, USB, Linux, microcontrolers, firmwares ... )
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You english syntax is somewhat laboured. I suggest having a technically
oriented English speaker rewrite the document. I would do it for 20
dollars per page, 50% payable in advance. No, I am not kidding. That is
dirt cheap. It could take up to an hour per page to make the language
comply with academic technical standards.
EC<:-}
DEMAINE Benoit-Pierre wrote:
| Quote: | -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
I have released the first full version of my thesis. I am looking for
rereaders to track syntax and phrasing problems.
The reader is expected to try to understand what I wrote, and report any
problem.
In short. it deals with building a camera WHICH HAS THE CAPABILITY OF |
TRACKING
any object. I had to build a USB development board based on the motorola
MC68HC908JB8,
write the monitor to upload the firmware under Linux, write the
firmware FOR THE MOTOROLA "PROCESSOR", write the user application THAT
PROCESSED THE
CAMERA INPUT, compute INTERPRETED MOVEMENT IN THE VIRTUAL FIELD
GENERATED BY THE INPUT,
and PRODUCE INSTRUCTIONS FOR the USB board to OPERATE the servo motors
ACTUATING the
camera.
# The above might sound a little stilted but colloquial language is not
allowed in a thesis.
EC<:-} |
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E. Charters
*nix forums Guru Wannabe
Joined: 20 Feb 2005
Posts: 156
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: Student looking for re-readers for his thesis ( it deals with embedded system, USB, Linux, microcontrolers, firmwares ... )
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Where you will get the most help...and I am sure you have thought
of this, is in a Canadian board, where Fr. speaking people who are
also fluently bilingual sympathize with your translational plight
and decide to take pity on you sufficient for their engagement in such
an ardous task as rewriting 70 pages of a document. This is a week's
work to get it write. (find the error in the last sentence)
comme ca -->
http://www.siliconinvestor.com/subject.aspx?subjectid=28756
Another idea is to get a chinese thesis advisor whose english is so
bad he won't notice the mistakes. It has worked for me.
EC<:-]
DEMAINE Benoit-Pierre wrote:
| Quote: | I still think you should get an english major to look at it.
Preferrably a really good looking one in your preference of gender.
Reward him/her by taking him/her out to dinner -- perhaps oysters with
lots and lots of wine. Then suggest that you need to go back to your
room to take another look. Then discover that you just happen to have
some champaign stashed away.
The rest is up to you, but remember: a good engineer kills two birds
with one stone.
Your two peaces of advice are quiet interesting, but I definitively can
not follow any of them at the moment.
:)
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E. Charters
*nix forums Guru Wannabe
Joined: 20 Feb 2005
Posts: 156
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: Student looking for re-readers for his thesis ( it deals with embedded system, USB, Linux, microcontrolers, firmwares ... )
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This will be really hard to correct. E.G."I expect some difficulties
about use of the clock" corrects to "I expect some difficulty [] with
use of the [] clock" It is easy to substitute, but is this correct? What
clock? You have a dangling reference. It is bad style, while
grammatically correct. Never assume that your thesis advisor knows a
grandfather clock from a MPU clock. [] must be filled in with
description or phrases that explain the terse phraseology.
"The last problem is to make everything work (chip+servos) only
consuming 500 MA as peak current."
One can see what you want to say.
"Finally the challenge is make the all components work, inclusive of
chips and servos, while only consuming a maximum of 500MA peak current."
Actually one does not consume peak current. One "reaches a level of
consumption that maximizes at [or does not exceed] a peak current of
500MA". The verb consume is active continuous in mood, whilst a peak
current usage is perforce transitory. Thus the meaning of the phrase is
corrupted.
The work of making this document correct and fluid is not trivial. Good
goddamned luck with it. It is not for amateurs.
EC<:-}
DEMAINE Benoit-Pierre wrote:
| Quote: | I still think you should get an english major to look at it.
Preferrably a really good looking one in your preference of gender.
Reward him/her by taking him/her out to dinner -- perhaps oysters with
lots and lots of wine. Then suggest that you need to go back to your
room to take another look. Then discover that you just happen to have
some champaign stashed away.
The rest is up to you, but remember: a good engineer kills two birds
with one stone.
Your two peaces of advice are quiet interesting, but I definitively can
not follow any of them at the moment.
:)
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Michael Schnell
*nix forums Guru Wannabe
Joined: 21 Feb 2005
Posts: 110
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: flash device selection
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| Quote: |
Wear leveling is usually done in the flash controller, regardless of
the
file system.
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That's a very bad idea. If the file system does not care about wear
leveling and keeps rewriting the same few bytes, the lower level wear
leveling uses up the spare blocks much faster then when using a
flash-aware file system like jff.
-Michael |
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Michael Schnell
*nix forums Guru Wannabe
Joined: 21 Feb 2005
Posts: 110
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: IPC between tasks in kernel
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| Quote: | I don't think a tasklet is the same as a kernel thread.
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Right. Tasklets seem to be more like ISRs for virtual interrupts.
| Quote: | I don't know about any fundemental change to the way
kernel threads works in 2.4 and 2.6. Of course kernel
threads also get advantages from the improved scheduler,
and a lot more kernel threads are used now.
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Good to know. Thanks.
-Michael |
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fjm_2@usa.com
*nix forums beginner
Joined: 19 Feb 2005
Posts: 1
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: compatible RT linux patch for Linux Ver 9 (2.4.20-8)
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Mahender wrote:
| Quote: | Hello,
From where I can download RT Linux patch for Linux ver
9(2.4.20-
or advanced kernel versions.
Please help me.
Mahender.
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I think that the "-8" might be vendor (distribution) specific. My
RedHat, for instance, is 2.4.20-6. I downloaded a 2.4.20 and patched
it (with RTAI). After the patch, it worked fine with the rest of the
distribution.
Frank |
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Michael Schnell
*nix forums Guru Wannabe
Joined: 21 Feb 2005
Posts: 110
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: IPC between tasks in kernel
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| Quote: | First - you don't have "tasks" in the kernel. You can have threads,
created by the kernel, that basically run within the kernel address space.
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The Kernel Threads sometimes are called "Taskslets"  .
I suppose with the kernel threads there are big differences between
Kernel v2.4.x and 2.6.x.
In a (German) article on 2.6 Kernel Threads (German Linux Magazine
11/03) I found those keywords that might be used as pointers:
Different types of "Kernel Threads": (1) running an a process context:
"Kernel Threads", "Workqueues", "Event-Workqueues". (2) running in an
Interrupt Context: "SoftIRQs", "Tasklets", "Timers".
Some more pointers: There are priorities. Race conditions need to be
looked at. "add_timer()" will call a kernel function after a predefined
time. "ps auxw" shows kernel Threads. "kernel_thread()" creates a kernel
thread (similar to "clone()" ). "wait_event_interruptible_timeout()"
makes a kernel thread sleep by a "waitqueue". "workqueues" might be
better than "waitqueues" created by "queue_delayed_work()" <this might
be the best answer to the original question>.
-Michael |
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Javier de Pedro
*nix forums beginner
Joined: 19 Feb 2005
Posts: 1
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: Determining geometry of Compact Flash
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download this document
http://www.sandisk.com/pdf/oem/cf-manual-10.7.pdf
It explains all about CF
Kevin D. Quitt wrote:
| Quote: | On 15 Dec 2004 05:13:01 GMT, Grant Edwards <grante@visi.com> wrote:
What do you mean by "geometry"? The number of 512-byte blocks
is the only geometry I'm aware of.
CF presents itself as having cylinders, tracks and sectors. lilo will not
work correctly unless it is given the correct values for those.
The actual geometry of the
flash chip(s) is hidden behind the IDE interface logic.
Except for when it isn't.
Even
if you did know the geometry of the flash chip(s) you couldn't
do anything with that information.
I can find out the geometry of the chip from the BIOS by booting to the
BIOS instead of linux. This is how I do it *now*. I then provide this
information to lilo, so that it can create a boot block that allows me to
boot from the CF into linux.
all kinds of geometries even when they're exactly the same size.)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
They're _not_ all the same size. That's the problem.
You're not reading what I wrote.
What you
have to do is standardize on a partition size that will fit on
all the parts from all the vendors.
Completely wrong. The partition size doesn't matter for booting; the
geometry does because lilo requires to know that geometry.
I do thank you for bothering to answer.
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Amit Limaye
*nix forums beginner
Joined: 17 Mar 2005
Posts: 25
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: IPC between tasks in kernel
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Please have a look at workqueues/taskqueues/waitqueues which will allow
u to manage synchronization problems and everything u could set up a
commom buffer between the the kernel threads/tasklets/tasks and use
waitquesues to signal availability of data
BTW semaphore are also available in the kernel which u can use for
syncing with shared buffers as mentioned earlier u dont need to
explicitly share buffers or data as all global data is visible to all
tasks in the kernel |
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Edwin Bland
*nix forums beginner
Joined: 19 Feb 2005
Posts: 2
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: armv4l-unkown-linux-gcc compiler problem!!
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Hi Chan,
I use a similar processor for a project at work. I've not used the
option you're trying to use -mapcs-32. However, I didn't know it was
possible to select multiple optimizations for the instruction sets, for
example,
tune-y :=
| Quote: | tune-$(CONFIG_CPU_ARM920T) :=-mtune=arm9tdmi
tune-$(CONFIG_CPU_SA1100) :=-mtune=strongarm1100
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The SA1110 is an ARM4 core. What does using the arm9tdmi tuning do for you?
Have you tried the default to see if you're able to build the project
without the -mapcs-32.?
Edwin Bland
Orange, CA
Chan Ka Cheong wrote:
| Quote: | Hi, I try to compile a bootloader "vivi" for my strongARM embedded
system. However, when i run "make"
/opt/host/armv4l/bin/armv4l-unknown-linux-gcc
-I/root/cheong/gsl/linuette/vivi/include -I/opt/host/armv4l/include/
-Wall -Wstrict-prototypes -O2 -fPIC -fomit-frame-pointer -mapcs-32
-mshort-load-bytes -msoft-float -c -o init/main.o init/main.c
as: ????? `-mapcs-32'
make: *** [init/main.o] Error 1
So what is the problem from "-mapcs-32"? As I refer to arm-opion for my
gcc-2.95.2
http://web.umr.edu/~gnudoc/single/gcc-2.95.2/gcc.html#SEC22
It should supported this options!
My gcc compiler is "armv4l-unknown-linux-gcc" and my Makefile under the vivi/arch/Makefile is like this:
--------------------------------------------------------------
# Select CPU dependent flags. Note that order of declaration is
important;
# the options further down the list override previous items.
#
# Note! For APCS-26 YOU MUST HAVE AN APCS-26 LIBGCC.A
#
apcs-y :=-mapcs-32
# This selects which instruction set is used.
arch-y :=
arch-$(CONFIG_CPU_32v4) :=-march=armv4
# This selects how we optimise for the processor.
tune-y :=
tune-$(CONFIG_CPU_ARM920T) :=-mtune=arm9tdmi
tune-$(CONFIG_CPU_SA1100) :=-mtune=strongarm1100
CFLAGS +=$(apcs-y) $(arch-y) $(tune-y) -mshort-load-bytes
-msoft-float
AFLAGS +=$(apcs-y) $(arch-y) -mno-fpu -msoft-float
ifeq ($(CONFIG_CPU_32),y)
PROCESSOR = armv
TEXTADDR = 0x00000000
endif
LDSCRIPT = arch/vivi.lds.in
ifeq ($(CONFIG_ARCH_SA1100),y)
MACHINE = sa1100
TEXTADDR = 0x00000000
endif
ifeq ($(CONFIG_ARCH_S3C2400),y)
MACHINE = s3c2400
ifeq ($(CONFIG_S3C2400_GAMEPARK),y)
TEXTADDR = 0x00000000
ifeq ($(CONFIG_S3C2400_GAMEPARK_OSSWITCH),y)
TEXTADDR = 0x00100000
endif
ifeq ($(CONFIG_S3C2400_GAMEPARK_ON_RAM),y)
TEXTADDR = 0x0C000000
endif
else
TEXTADDR = 0x00000000
endif
endif
... ....
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Kasper Dupont
*nix forums Guru
Joined: 20 Feb 2005
Posts: 1167
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: IPC between tasks in kernel
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Michael Schnell wrote:
| Quote: |
First - you don't have "tasks" in the kernel. You can have threads,
created by the kernel, that basically run within the kernel address space.
The Kernel Threads sometimes are called "Taskslets" .
|
I don't think a tasklet is the same as a kernel thread.
But I think in recent kernels tasklets are implemented
using kernel threads. Somebody knowing tasklets a bit
better may fill in the blanks.
| Quote: |
I suppose with the kernel threads there are big differences between
Kernel v2.4.x and 2.6.x.
|
I don't know about any fundemental change to the way
kernel threads works in 2.4 and 2.6. Of course kernel
threads also get advantages from the improved scheduler,
and a lot more kernel threads are used now.
--
Kasper Dupont |
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Mark H Johnson
*nix forums beginner
Joined: 19 Feb 2005
Posts: 4
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: IPC between tasks in kernel
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VSS wrote:
| Quote: | Hi Guys,
My question was pertaining to tasks *inside* the kernel. What I really
want to do is this.
First - you don't have "tasks" in the kernel. You can have threads, |
created by the kernel, that basically run within the kernel address space.
| Quote: | I have some callbacks which get called in the kernel.
What is the context that this callback function gets called [e.g., |
interrupt, with or without locks held, allowed to sleep, ...]?
Your solution will vary based on the context of the implementation.
| Quote: | I want to send a
cook up a message and send it to the other task(B). Task B just keeps
waiting for these messages and handles the message. Is it possible to do
this?
Certainly. |
Look at the interfaces that implement one of [from a recent 2.6 kernel] ...
- [ksoftirqd/#]
- [pdflush]
- [aio/#]
- [kjournald]
There are about two dozen of these kernel threads on my 2 CPU system.
Review how hey work / choose the method that matches your situation the
closest / implement the same interface. A quick grep...
# grep -ir pdflush /usr/src/linux-2.6.10/
gives a couple hundred hits including comments on a pool of worker
threads, structures for passing work to those threads, a list of
operations to perform, protection by locks, and so on. That certainly
covers all the bases but may be "too heavy" for your application.
--Mark |
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Kasper Dupont
*nix forums Guru
Joined: 20 Feb 2005
Posts: 1167
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| Posted: Sat Feb 19, 2005 10:29 pm Post subject:
Re: IPC between tasks in kernel
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VSS wrote:
| Quote: |
Hi Guys,
My question was pertaining to tasks *inside* the kernel. What I really
want to do is this.
I have some callbacks which get called in the kernel. I want to send a
cook up a message and send it to the other task(B). Task B just keeps
waiting for these messages and handles the message. Is it possible to do
this?
|
Why do you want to do that? Why do you want to communicate
with a different thread, when you can just do it yourself?
--
Kasper Dupont |
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