RE: Device node - How does kernel know about it

2007-12-27 Thread Siva Prasad
er program. Eventually it will result in a call to what ever read routine registered, but that must be a call back function or some thing. Right? - Siva -Original Message- From: Phillip Susi [mailto:[EMAIL PROTECTED] Sent: Thursday, December 27, 2007 12:10 PM To: Siva Prasad Cc: li

Device node - How does kernel know about it

2007-12-26 Thread Siva Prasad
Hi, How do the device nodes work as an interface between user and kernel programs, and how to go debugging it? This is as part of my debugging effort on an embedded board. * It all started with the problem of "not printing" any thing that comes from ramdisk (echo and printf statements), while ke

Testing RAM from userspace / question about memmap= arguments

2007-12-20 Thread Siva Prasad
Hi Matthew, I worked on some thing similar. For one of our customer product that goes to defense and security markets, we had to support maximum possible memory test. We implemented a mechanism of pre-test to test the memory with walking 1's and 0's just before Linux kernel starts allocating

RE: printf internals

2007-12-19 Thread Siva Prasad
M To: Siva Prasad Cc: Clemens Koller; David Newall; linux-kernel@vger.kernel.org Subject: RE: printf internals On Wed, 2007-12-19 at 14:33 -0800, Siva Prasad wrote: > Thank you very much for your response Clemens. > > I tried strace on a regular system. It does not show which tty, e

RE: printf internals

2007-12-19 Thread Siva Prasad
14, 2007 8:16 AM To: David Newall Cc: Siva Prasad; linux-kernel@vger.kernel.org Subject: Re: printf internals David Newall schrieb: > Siva Prasad wrote: >> I am looking at how exactly does the printf in user programs succeeds in >> displaying characters to the serial console

printf internals

2007-12-13 Thread Siva Prasad
Hi, I am looking at how exactly does the printf in user programs succeeds in displaying characters to the serial console. printf uses /dev/console to write the data. Once written to /dev/console, what happens to the string written? Is there any way, I can get access to those prints/string inside

Ramdisk Vs NFS

2007-04-24 Thread Siva Prasad
Hi, What is the primary difference between Ramdisk and NFS with respect to the wait_queue's? If I use ramdisk, every thing works fine, but with NFS (or you may read as 'no ramdisk') kernel/sched.c:__wake_up_common() routines has a problem. Basically the value of "&q->task_list->next" is out of o

No Subject

2001-05-16 Thread siva prasad
Sorry for the newbie question.. Is it true that the ipc calls like msgget(),shmget()... are not really system calls? Cos in the file "asm/unistd.h" where the system calls are listed as __NR_xxx we dont find the appropriate listing for the ipc calls. What I guessed was that all the ipc calls are