QNX RTOS v4 Knowledge Base
QNX RTOS v4 Knowledge Base
| Title |
Sample code for calculating physical memory in QNX4. |
| Ref. No. |
QNX.000009575 |
| Category(ies) |
Kernel, Development |
| Issue |
Is there a way to calculate the physical memory location of a particular process and if so, how would you do it?
|
| Solution |
Yes, here is some sample code on how to do this.
#include <sys/types.h>
#include <sys/seginfo.h>
#include <sys/inline.h>
#include <i86.h>
int
vtop(caddr_t v, paddr_t *p)
{
unsigned long l = (unsigned long)v;
int sel;
struct _seginfo d;
if (qnx_segment_info(0,0, _ds(), &d) != _ds() ||
(sel=qnx_segment_overlay(d.addr+(v&~(PAGESIZE-1)), PAGESIZE,
_PMF_VOVERLAY)) == -1 ||
qnx_segment_info(0,0,sel, &d) != sel) {
return -1;
}
*p = d.addr+(v&(PAGESIZE-1));
return 0;
} |
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