[OpenIndiana-discuss] oracle removes 32bit x86 cpu support for solaris 11 will OI do same?

[Richard L. Hamilton]

On Jun 24, 2011, at 4:17 PM, Dmitry Kozhinov wrote:

> > So I guess it would be fair to say that the best OS is the one that
> > support both at the same time
> 
> Yes, and that's OSol and OI do.

Processes running under 32-bit Solaris can only be 32-bit.
Processes running under 64-bit Solaris can be either.

However, drivers, etc must match the kernel.  And for all
practical purposes, debugging a process (or the kernel)
is a whole lot easier when done by a process with the same
bitness as what it's debugging.  For instance, it may not
be feasible for a 32-bit process to control a 64-bit process
(although the reverse may be possible, if more difficult than
if they were the same).

So the loss of a 32-bit kernel option limits mainly the
hardware you can run on (CPU, but maybe also old drivers that
were never ported to 64-bit).

Other OS's may have somewhat different rules. OS X for instance
can run 64-bit processes on a 32-bit kernel given 64-bit capable
hardware.  I expect that very few OS's would go to the trouble of
supporting 32-bit drivers on a 64-bit OS, for example; not perhaps
100% impossible depending on the driver-to-OS interface, but
certainly extra complexity where it's most dangerous.