Re: mips64 on port-cobalt

Matt Thomas <[email protected]> Fri, 18 Dec 2009 16:44:43 -0800
Newsgroups gmane.os.netbsd.ports.cobalt
Message-ID <[email protected]>
On Dec 18, 2009, at 8:54 AM, Alex Pelts wrote:

> Not that this should stop anyone from trying, but I am not sure Qube
> will gain anything by going 64 bit. While RM5231 processor is certainly
> 64bit, the system interface is 32bit so for every data memory read and
> write it will require 2 accesses in 64 bit mode. Also data cache will be
> effectively cut in half if most of the structure size would double due
> to going to 64 bit.

Actually, the N32/N64 ABIs are higher performing that the old O32 ABI.  Which is
why I highly recommend using a N32 kernel.