QNX RTOS v4 Knowledge Base
QNX RTOS v4 Knowledge Base
| Title |
virtual/physical memory access |
| Ref. No. |
QNX.000003215 |
| Category(ies) |
Development |
| Issue |
The qnx_segment_alloc_flags() only allows the allocation of 64k blocks for ISA DMA devices. How does one allocate any size block of contiguous memory in the 0-16Mbyte range and get its physical address?
|
| Solution |
There is an undocumented flag you can use with qnx_segment_alloc_flags()...
_PMF_DMA_HIGH....
You can look at some examples using the PMF_DMA_* in /etc/readme/technotes/shmem.txt |
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