New NetBSD/amd64 Snapshot

fvdl writes "As the number of AMD64 users grows, new snapshots of NetBSD/amd64 will be made available on a regular basis, until the next NetBSD release (2.0) is out. NetBSD/amd64 is almost two years old by now, but did not have a formal release yet, since hardware was not publicly available at the time of the last major NetBSD release. The latest snapshot is available at ftp.netbsd.org. It is a fully-featured NetBSD port, made available in the form of a bootable ISO image."

Why?

[Orthanc_duo]

Why do they need a port for AMD.. AMD chips still run the x86 command set don't they??
or has it just been optimised for AMD processors?

Re:Why?

[nitehorse]

This is for the K8/Sledgehammer/Opteron architecture - NetBSD runs in full 64-bit mode on it.

Re:Why?

[zzyp]

Why do they need a newer gcc to compile 64 bit code? The current ones dont do that now eh?
I am waiting till next year to assemble myself a nice 2+ Ghz AMD64 machine.

Re:Why?

[hubertf]

The amd64 platform is a true 64 bit platform (hence the name :). As such, it uses 64bit entities for longs and pointers internally, which is just not compatible with the legacy PC software.

To still run legacy software, an emulation layer had to be added that maps all 32bit entities (longs, pointers, ...) that applications pass on system calls into their 64bit in-kernel equivalents, and back.

That emulation layer was already necessary for the NetBSD/sparc64 port, to run NetBSD/sparc (and 32bit Solaris, etc.) binaries on 64bit platforms. It was not necessary for the NetBSD/alpha port, as there are no 32bit binaries, and it can operate in 64bit without taking care of backward compatibility.

Would be interesting to hear how other operating systems deal with the situation btw - FreeBSD, Linux, Windows anyone?

- Hubert

Re:Why?

[the-dude-man]

Basically its so you can compile for the single set of 64 bit registers in the cpu

Without it, There really isnt a whole lot of point in using an Athlon64 cpu.

You may use AlthlonXP and get half the price and a bigger space heater if you use the 32Bit binarys

Why not?

[rumpledstiltskin]

optimizing an operating system for a processor is probably a good thing. you can make apps go that much faster, and it would probably be more stable. the only downside is it may lead to a fragmentation of the operating system (countered by the upside of expanding the user base, though)

Re:Why not?

[compudroid]

NetBSD prides themselves on their clean code working on over 50 archs i beleive. 30 something considered stable. Adding a port to a new arch hasnt fragmented NetBSD thusfar, I see no reason why this one would.

Re:Why not?

[evilcyber]

Actually, the number is 40+.

(As of this writing, there are 40 arches in the automated build loop, amd64 has not yet been added to the autobuild.)