Problem with decrementer interrupt

sumedh tirodkar sumedhtirodkar at gmail.com
Tue Feb 24 04:04:25 EST 2009


Alright...I am trying to develop a system of my own..
Consider that i am not using any linux kernel...I m writing some
program right from scratch.........
The major steps that i have taken are...

1. Started with a assembly file...
2. Have relocated the interrupt handlers to there respective
positions...The interrupt handlers are written in assembly language...
3. Initialised Decrementer register to get an interrupt after some interval...
4. Jump to some function using

    bl <function_name_main>

    function_name_main which will have a infinite while loop..
This works fine i.e. the interrupts(decrementer interrupt to be more
specific) work fine...I have initialised serial port to get the
output...

Now, the problem that i am facing....

If in interrupt handler of the decrementer, i make a call to some C
function in some other C file...using the follwing statement...

Dec_handler:  /* I have relocated this to interrupt vector address of
decrementer interrupt*/
     /*code to print using serial port*/
     bla <function_name_handler> /*code to call some function in C file*/
     /*code to print using serial port---but i m never able to see this output*/
     RFI

This starts creating a problem...somehow we dont return to this code
after the end of the function_name_handler...
Consider the following code for the function_name_handler:
void function_name_handler(void)
{
   /*Some action*/
}

So, if its possible for anyone to help me with this...please reply...

Regards,
Sumedh


On Mon, Feb 23, 2009 at 8:18 PM, Matt Gessner <mgessner at gmail.com> wrote:
>
>
> On Mon, Feb 23, 2009 at 8:03 AM, sumedh tirodkar <sumedhtirodkar at gmail.com>
> wrote:
>>
>> I am using PowerPC 7447A...I am trying to port SA-RTL on PowerPC...
>
> What I said earlier was: You need to tell people what cpu you're using, what
> linux kernel, etc etc etc.
>
> Fine, we know the CPU.  What kernel are you using?  Is it ancient?
>
> I doubt the information below is going to be useful...
>
>>
>> I am using
>>
>> bla <function_name>
>>
>> from the assembly code to call the function in C file...This i am
>> doing from interrupt handler of the decrementer...
>> If any more details are required, please let me know...
>
>



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