[PARISC] Document history of PDC_NARROW as it is now obsolete

Document history of PDC_NARROW a bit as it will still show
up in an older kernel's .config file.

Signed-off-by: Grant Grundler <grundler@parisc-linux.org>

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
This commit is contained in:
Grant Grundler 2005-10-21 22:51:40 -04:00 committed by Kyle McMartin
parent c8e8b1937a
commit 675ec7a56a
1 changed files with 8 additions and 8 deletions

View File

@ -83,15 +83,15 @@ static unsigned long pdc_result2[32] __attribute__ ((aligned (8)));
int parisc_narrow_firmware = 1;
#endif
/* on all currently-supported platforms, IODC I/O calls are always
* 32-bit calls, and MEM_PDC calls are always the same width as the OS.
* This means Cxxx boxes can't run wide kernels right now. -PB
/* On most currently-supported platforms, IODC I/O calls are 32-bit calls
* and MEM_PDC calls are always the same width as the OS.
* Some PAT boxes may have 64-bit IODC I/O.
*
* CONFIG_PDC_NARROW has been added to allow 64-bit kernels to run on
* systems with 32-bit MEM_PDC calls. This will allow wide kernels to
* run on Cxxx boxes now. -RB
*
* Note that some PAT boxes may have 64-bit IODC I/O...
* Ryan Bradetich added the now obsolete CONFIG_PDC_NARROW to allow
* 64-bit kernels to run on systems with 32-bit MEM_PDC calls.
* This allowed wide kernels to run on Cxxx boxes.
* We now detect 32-bit-only PDC and dynamically switch to 32-bit mode
* when running a 64-bit kernel on such boxes (e.g. C200 or C360).
*/
#ifdef __LP64__