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Re: How to create a fixed address for a vaiable ??

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hemanthvenkatappa@gmail.com wrote:
> Example : int a[30];
> 
> If i initialize as above in my c program. How to make that variable to
> have a fixed address. So that I can use the variable name and addresses in
> the A2l file. I am using QNX momentics IDE (QNX RTOS) and Eclipse ide (for
> Linux RTOS).
> 
> If I run the program multiple times then the address will be keep on
> changing.
> Could anyone tell me how to get a fixed address for the variable ??

I don't know why you would need/want this but here is how you can do it. 
Note that I'm assuming the address in question is for normal memory and not 
some device DMA or IO.

#include <sys/mman.h>

int main() {
void* const address = (void*)0x0000000010000000; //Example address
const size_t size = sizeof(int[30]);

void* mmap_address = mmap(address, size, PROT_READ | PROT_WRITE, MAP_PRIVATE 
| MAP_FIXED | MAP_ANONYMOUS, -1, 0);

if( mmap_address != address ) {
  return 1; // mmap failed
}

int* a = (int*)address;
a[0] = 0;
a[29] = 0;

return 0;
}

Regards.
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How to create a fixed address for a vaiable ?? hemanthvenkatappa@gmail.com - 2014-01-20 16:23 -0800
  Re: How to create a fixed address for a vaiable ?? Lusotec <nomail@nomail.not> - 2014-01-21 10:57 +0000
  Re: How to create a fixed address for a vaiable ?? Tim Roberts <timr@probo.com> - 2014-01-21 22:26 -0800
    Re: How to create a fixed address for a vaiable ?? Hemanth Venkatappa <hemanthvenkatappa@gmail.com> - 2014-01-22 01:03 -0800
      Re: How to create a fixed address for a vaiable ?? Hemanth Venkatappa <hemanthvenkatappa@gmail.com> - 2014-01-22 01:05 -0800
        Re: How to create a fixed address for a vaiable ?? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2014-01-22 15:24 +0000
          Re: How to create a fixed address for a vaiable ?? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-01-22 21:16 +0200
            Re: How to create a fixed address for a vaiable ?? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2014-01-22 20:04 +0000
              Re: How to create a fixed address for a vaiable ?? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2014-01-22 22:47 +0200

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