Anupam Chomal wrote: > Hi All, > > I am trying to write drivers that should be "Solaris compliant". By > this I mean that the driver should be - DDI or DKI or LDI compliant. > Now my doubts are: > > 1. There are extern decelerations in header files available in > solaris. Can we use then directly while writing our kernel modules or > not?
Symbols in header files are not necessarily reliable. What's reliable is the documentation -- section 7 (and 7i, 7m, and so on). By all means, use the header files to help locate things you need, to augment your understanding of the system, and to confirm the expected usage. They're certainly not "secrets" of any sort. But don't believe that because you find something there that it'll be stable over time. > 2. I assume the LDI is a subset of DDI/DKI interfaces...now my > confusion is, should a driver be DDI or DKI or LDI complient or all? I wouldn't say that's really an important distinction or consideration for any real software. The real issue is whether or not you rely on undocumented interfaces or behavior. If you do, then your driver may cease to operate properly (and may even cause panics or system crashes) after a patch or other upgrade to the system. It may do so without warning, and regardless of how much testing you think you've done, and the OS vendor may not necessarily expend much effort trying to fix your problems. If you stick to the documented interfaces and use them in the ways and contexts in which they're documented to be used, then the above sort of trouble is very much less likely to happen, and the vendor has a much keener interest in making things right. The documented interfaces form a sort of contract between the OS developers and the third party software writers: the OS people promise not to change these things in incompatible ways without substantial advance notice and without a really good reason, and the driver writers in turn promise not to wander off the reservation. > 3. Certain DDI interfaces, like ddi_pathname_to_dev_t, do not have man > pages. Does this mean that it is not a public interface? Then why is > it a DDI interface? DDI is supposed to be public and make drivers > portable right? The sys/sunddi.h header file is a bit of a grab-bag. It contains some things that are documented and public, and others that are clearly private. I believe that ddi_pathname_to_dev_t (which is not documented) was once classified as "Sun Private." I wouldn't suggest confusing the letters "ddi" in the symbol name or in the header file name as any sort of promise of stability. If you care about writing a good, stable driver, don't use it. OpenSolaris is no more. If your question is about Solaris, then you need to talk to your local Oracle representative to find out whether this function could be made public (and thus documented and stable for use by independent driver writers). If your question is about OpenIndiana, then one of the OpenIndiana mailing lists is probably your best bet. -- James Carlson 42.703N 71.076W <carls...@workingcode.com> _______________________________________________ opensolaris-code mailing list opensolaris-code@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/opensolaris-code
