The reason that i m using bla is that i am writing the interrupt
handler from dec_start: to dec_end:....
then i am relocating this code to its corresponding vector
location(0x900)...As this relocated code is gonna be executed on
occurrence of interrupt, i cant use bl instruction...i have to go for
bla...
The C code is getting executed for sure...hav checked this using some
debug message...But the return from that function is not
happening...somehow the link register is not getting properly
loaded...dont knw wat is the reason behind this...

Regards,
Sumedh

On Tue, Feb 24, 2009 at 1:24 PM, sjoyeau@wanadoo.fr [off-list ref] wr=
ote:

Sumedh,

I've just noticed you are using the "bla" instruction, which use absolute
target address: are you sure the C code gets even be executed ?
I don't know how the compiler successfully assemble your code because the
binary is supposed to be position independant code (PIC): you should rath=

er

use "bl" instruction (relative branch).

--
sj

2009/2/23 sumedh tirodkar [off-list ref]

quoted

I have initialised to stack pointer(r1) properly...actually...i went
thru the object dump...bt when i juz use

 bla <function_name_handler>

the link register is not getting pushed on to the stack in the prolog
of that function...so the stack is basically not coming into the
picture...
@IRQ originator, that doesn't seem to be a problem...

The only thing that i am able to think of is that when i do a "bla",
the return address is not getting stored in link register...and i m
not able to figure out why...

Regards,
Sumedh

On Mon, Feb 23, 2009 at 11:03 PM, sjoyeau@wanadoo.fr <sjoyeau@wanadoo.fr=

quoted

wrote:

quoted

Hi Sumedh,

You may check the context in which your CPU in running the C code from
interrupt context (ie stack pointer (r1), kernel locks disabling
rescheduling etc..) and double check the IRQ originator (the
decrementer) is
acknowlegded somewhere your handler before enabling back interrupts,
else
your handler gets fired.

--
sj

2009/2/23 sumedh tirodkar [off-list ref]

quoted

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..=

.

quoted

quoted

quoted

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 thi=

s

quoted

quoted

quoted

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 [off-list ref]
wrote:

quoted

On Mon, Feb 23, 2009 at 8:03 AM, sumedh tirodkar
[off-list ref]
wrote:

quoted

I am using PowerPC 7447A...I am trying to port SA-RTL on PowerPC..=

.

quoted

quoted

quoted

quoted

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...

quoted

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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--
------------------
Sylvain JOYEAU
Freelance Engineer
Software RT-OS R&D
sylvain.joyeau@gmail.com
T=E9l: +33-(0)667 477 052
"A good idea is one side of the coin. The other side is the practical
usefulness". J. Liedke.

--
------------------
Sylvain JOYEAU
Freelance Engineer
Software RT-OS R&D
sylvain.joyeau@gmail.com
T=E9l: +33-(0)667 477 052
"A good idea is one side of the coin. The other side is the practical
usefulness". J. Liedke.