Re: C programming resource
Pasting this from the faq doc Anuz recently prepared (with help from others on this list) for newbies. Thanks, Hiren C language programming books: 1. The C programming language by Kerninghan and Ritchie. Its a must-have book, most code in Kernel is written in C language and mastering C is important and there is nothing better than KnR for this job. 2. Practical C programming by By Steve Oualline Good book for developing a good coding style in C language 3. C traps and pitfalls by Andrew koeing A book which talks about limitations and issues with C programming, a very helpful textbook to understand where you can make mistakes. 4. Expert C programming: deep C secrets by Peter V Linden A very good books, which teaches a lot of nuances of C language. 5. The C programming Manual by Harbison and Steele This book ventures deep into the C programming language mostly details of standards and changes in C, its quite advance in nature. On Mon, Nov 22, 2010 at 9:37 PM, Sameer Rahmani lxsam...@gmail.com wrote: Hi, i'm not a C programmer , but i have a medium level of C programming knowledge that i think its not enough for spend time on kernel source. so could you people guide me for choosing a good resource for improving my C programming knowledge?
Re: is there still an active kernel janitors project?
Hi Robert, I would be interested in getting started :) Thanks, Hiren On Sun, Nov 21, 2010 at 5:06 AM, Robert P. J. Day rpj...@crashcourse.cawrote: i can suggest some very specific cleanups people can work on if they're bored. one related to lists: list_for_each() - list_for_each_entry() calls that is, modifying the numerous (older-style) list_for_each() calls to the more convenient list_for_each_entry() calls, something that can be done little by little, a subsystem at a time. good way to jump into kernel janitor work and get your name in the log. rday -- Robert P. J. Day Waterloo, Ontario, CANADA http://crashcourse.ca Twitter: http://twitter.com/rpjday LinkedIn: http://ca.linkedin.com/in/rpjday -- To unsubscribe from this list: send an email with unsubscribe kernelnewbies to ecar...@nl.linux.org Please read the FAQ at http://kernelnewbies.org/FAQ
Re: structure for Super IO chip detection
On Thu, Nov 18, 2010 at 5:47 AM, Bond jamesbond.2...@gmail.com wrote:
On this link
http://lxr.free-electrons.com/source/drivers/parport/parport_pc.c?v=2.6.29#L97
they defined a structure superio_struct and initialized as
superios[NR_SUPERIOS] = { {0,},};
I am not able to understand above initialization has what is it
getting initialized to.
Please put it into a small c prog and try it yourself. You will come to know
in a minute.
Thanks,
Hiren
Re: structure for Super IO chip detection
On Thu, Nov 18, 2010 at 9:58 PM, Bond jamesbond.2...@gmail.com wrote: On Thu, Nov 18, 2010 at 10:56 PM, hiren panchasara hiren.panchas...@gmail.com wrote: Please put it into a small c prog and try it yourself. You will come to know in a minute. I am not able to understand what program do I make to put thats why I asked. A simple C program with only 2 things: 1) structure that you are confused about - simply copy and paste 2) printf statement to see how values are assigned. Now change the value in 1) while initializing the structure and repeat. You should be able to find how structures are declared/defined/used in any good C programming book. Thanks, Hiren
Re: OS in-memory structure
On Thu, Oct 7, 2010 at 9:28 AM, Juan Rafael Garcia Blanco jgblanco.m...@gmail.com wrote: Hi, it has just been solved, thank you Would you care to share? Thanks. On Oct 7, 2010, at 5:55 PM, Juan Rafael Garcia Blanco wrote: Hi. During the boot process, Linux is loaded in main memory. When a system call is done, the OS executes again. If the system call is accompanied by some parameter, which is an address of the user process memory map, how can the kernel access that variable which is in user process memory map? I mean, when the kernel fires up an address, how is it translated? I can't find an answer to my question in books nor in the internet. Thank you very much -- To unsubscribe from this list: send an email with unsubscribe kernelnewbies to ecar...@nl.linux.org Please read the FAQ at http://kernelnewbies.org/FAQ
Re: Integer Division on 32 Bit Machines
On Tue, Sep 7, 2010 at 11:22 PM, Bond jamesbond.2...@gmail.com wrote: On Tue, Sep 7, 2010 at 11:29 PM, hiren panchasara hiren.panchas...@gmail.com wrote: Bond, This should help: http://en.wikipedia.org/wiki/Typedef Thanks I read that. but in the question which original poster asked he mentioned signed long s64. I am not clear with that. What exactly is your question? Please elaborate. Thanks, Hiren
Re: Integer Division on 32 Bit Machines
On Tue, Sep 7, 2010 at 11:53 PM, Bond jamesbond.2...@gmail.com wrote: On Wed, Sep 8, 2010 at 12:22 PM, hiren panchasara hiren.panchas...@gmail.com wrote: What exactly is your question? Please elaborate. In the code signed and unsigned word are used what is that and why is that used? First search in google gave me this: http://www.rwc.uc.edu/koehler/comath/13.html I think you should read up more on C. http://www.amazon.com/Programming-Language-2nd-Brian-Kernighan/dp/0131103628 Thanks, Hiren
Re: Integer Division on 32 Bit Machines
Bond, On Tue, Sep 7, 2010 at 10:44 AM, Bond jamesbond.2...@gmail.com wrote: On Tue, Sep 7, 2010 at 3:32 PM, Andreas Leppert wu...@web.de wrote: Hello, I have encountered a problem on my 32 bit machine. Here some code snippets: typedef signed long s64; Hi sorry my reply wont help you. Since I was reading this thread wanted to know what is the meaning of typedef signed long s64 I searched at Google but could not find it. This should help: http://en.wikipedia.org/wiki/Typedef Thanks, Hiren -- Everything is okay in the end, if it's not ok, then it's not the end.
Re: A question
Thanks a lot Prabhu for great explanation, comments in-line: On Wed, Sep 1, 2010 at 10:02 PM, Prabhu nath gprabhun...@gmail.com wrote: Interrupt context is a loaded term. It is used for both top-half and bottom-half processing. I need some more reading, will do that :) Linux defines two terms in the top-half, one is Interrupt handler (IH) and Interrupt Service Routine (ISR). Interrupt handler is a standard kernel code that is executed by the processor once the interrupt is generated. To abstract it, this generic code is executed for all the generated interrupts. This, in general saves the present processor context and paves way for the execution of ISR. ISR is a interrupt service routine written by a device driver programmer to handle the interrupt of a device. ISR is mainly responsible to verify the status register of a device to find out the cause of the interrupt and act accordingly. Both IH and ISR will not have a context of its own. Interrupts generated by a hardware device is asynchronous. i.e. it can be generated at any point in time. When such a interrupt is generated, the current execution is interrupted and the execution control is transferred to IH and ISR will be executed. Thus we can infer that both IH and ISR will be executing in an anonymous context. I am struggling to find meaning of interrupt context now. For Eg. Consider there are 3 tasks T2, T3. Suppose T2 invoked a read system call to read data from the secondary media (say hard disk), driver of the hard disk will initiate the device to gather the data and put task T2 in the wait queue and invokes scheduler. Now, scheduler picks up say T3. When processor is executing task T3, there was interrupt generated by the harddisk controller indicating that data is ready. At this point IH and ISR is executed. IH and ISR of this interrupt has no relevance to task T3, but still it is executed in the context of T3. Hence we say that IH and ISR will always be executed in the anonymous context. Wow, didnt know this. So IH and ISR wont execute in interrupt context? What is interrupt context then? and if they execute in context of T3, does it have any side-effect on processing of T3? Most of the bottom half execution happens the same way, i.e. it will be executing in the anonymous context unless the job of bottom half is relegated to respective kernel threads. In the latter case the bottom half execution will have its own context. For more details about top-half and bottom half, refer ULK 3rd edtion by Bovet, Chapter 4 Would read it. Thanks again for great insights. Regards, Prabhu On Wed, Sep 1, 2010 at 9:08 PM, Hiren Panchasara hiren.panchas...@gmail.com wrote: Process context is schedulable but interrupt context is not. Why and how? Any examples I can look at? Thanks. -- To unsubscribe from this list: send an email with unsubscribe kernelnewbies to ecar...@nl.linux.org Please read the FAQ at http://kernelnewbies.org/FAQ
A question
Process context is schedulable but interrupt context is not. Why and how? Any examples I can look at? Thanks. -- To unsubscribe from this list: send an email with unsubscribe kernelnewbies to ecar...@nl.linux.org Please read the FAQ at http://kernelnewbies.org/FAQ
