I want to mmap a device in an application, so I do:
base = mmap(NULL , DEV_LENGTH, myprot , flags, kmem, dev_base);
Turns out that some BIOSs put my device at an address like
whereas others put it at 0xfa000000 . In the latter case, mmap works
as expected. However in the first case I get EINVAL: The base is
However, in the latter case I get my requested 1k of memory, and the
following 3k for free. In the first case I'd want "3k for free,
followed by the 1k I requested".
effectively, provided "start" equals NULL, the kernel IMHO should:
offset = dev_base & PAGE_MASK;
return mmap (NULL, length+offset, prot, flags, base - offset) + offset;
The "failure" was observed on 2.4.14 and/or 2.4.9.
P.S. I end up not being able to closely follow linux-kernel
lately. CCs to me appreciated.
-- ** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 ** *-- BitWizard writes Linux device drivers for any device you may have! --* * There are old pilots, and there are bold pilots. * There are also old, bald pilots. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to firstname.lastname@example.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/