ULK = Understanding Linux Kernel 3rd edition - Bovet and Cesati On Mon, Sep 20, 2010 at 10:22 AM, Sri Ram Vemulpali <sri.ram.gm...@gmail.com > wrote:
> Here is the Intel system programming guide of x86. > By the way what is ULK haven't come across it. > > Thanks, > Sri. > > > On Mon, Sep 20, 2010 at 12:07 AM, Prabhu nath <gprabhun...@gmail.com>wrote: > >> There is a macro called *common_interrupt* which calls do_irq. >> "arch/x86/kernel/entry_32.S" >> >> Please refer ULK page 162 for more description. >> >> Can you please share the data sheet of x86. >> >> Regards, >> Prabhu >> >> >> >> On Mon, Sep 20, 2010 at 7:20 AM, Sri Ram Vemulpali < >> sri.ram.gm...@gmail.com> wrote: >> >>> Thanks for the replies. >>> >>> I have another question. Thanks in advance for clarifications. >>> >>> I was wondering who calls the do_irq function. >>> I mean when interrupts occurs processor should handle it by interrupting >>> current task. >>> So, when interrupts occurs in linux kernel, then, did processor jumps >>> directly to do_irq >>> or does it executes any other function before entering in to do_irq. >>> >>> If processor directly jumps to do_irq, then how does processor knows what >>> to execute >>> when interrupts happens. I mean, Is there anyway to set in linux kernel >>> to tell processor >>> to jump to this location when an interrupt or exception happens. I am not >>> talking about >>> interrupt subsystem, which is done in do_irq, checking what interrupt >>> occurred by reading bus, >>> and calling appropriate handler. >>> >>> Let me know whether my understanding is right. >>> >>> Thanks, >>> Sri. >>> >>> >>> On Sun, Sep 19, 2010 at 7:27 AM, arshad hussain >>> <arshad.su...@gmail.com>wrote: >>> >>>> On 9/19/2010 4:49 AM, Sri Ram Vemulpali wrote: >>>> >>>>> Hi all, >>>>> >>>>> This question is regarding Interrupt descriptor table. Why is the >>>>> IDTR 48-bits wide and >>>>> >>>> >>>> 16Bit Limit + 32 bit Address = 48bits of IDTR. >>>> >>>> >>>> why do we need limit field in the IDTR. >>>> >>>> Because if we access beyond defined interrupt there will >>>> be general protection fault. >>>> >>>> >>>> Since we know there are 256 interrupts or exceptions possible, can't >>>>> we know boundary by deriving it by length of IDT field. >>>>> >>>> >>>> All interrupts are not always defined. There may be fewer >>>> interrupts defined depending upon the requirements. Looking >>>> up the 'limits' field is faster & less error prone than >>>> find the length of the IDT, which i guess could only be >>>> done via probing for all slots with has present flag set to 0. >>>> >>>> >>>> Also, why is the IDT entry is 8 bytes long. >>>>> >>>> This 8 byte data structure is explained in intel's manual. >>>> >>>> And how is the interrupt >>>> >>>>> line sharing is provided. Is sharing provided at OS code level. >>>>> >>>> >>>> I did not see any explanation of sharing at Intel manual (data sheet >>>>> of x86 system programming guide). Any thoughts. >>>>> >>>>> Please clarify. Thanks. >>>>> >>>>> >>>>> -- >>>>> Regards, >>>>> Sri. >>>>> >>>>> >>>> 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 >>>> >>>> >>> >>> >>> -- >>> Regards, >>> Sri. >>> >>> >> > > > -- > Regards, > Sri. > >
