QNX RTOS v4 Knowledge Base
QNX RTOS v4 Knowledge Base
| Title |
Accessing BIOS from Protected mode. |
| Ref. No. |
QNX.000006802 |
| Category(ies) |
Development |
| Issue |
I would like to access the BIOS when running in protected mode? Is there somewhere where I can put information where the OS can get it?
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| Solution |
Upper memory, then use shm_open() and mmap() to access it. Look at Intel architecture manual to see what is unused by other BIOS functions.
Currently, the function shm_open() merely prepends a QNX-specific prefix to the given name, and calls open(). Portable programs will use shm_open() to create regions and ltrunc to set the region size. mmap() maps a portion (possibly all) of a shared region into an unused area of the callers address space, and returns a pointer to the beginning of this area.
See Also: The Watcom C Library Reference Manual entries for shm_open(), mmap(), ltrunc() and shm_unlink().
For more information on using shared memory see the file /etc/readme/technotes/shmem.txt on any QNX 4.2X version |
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