Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
Endianity with Linux on Itanium hardware
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Gentoo on Alternative Architectures
View previous topic :: View next topic  
Author Message
emilsa
n00b
n00b


Joined: 22 May 2005
Posts: 2

PostPosted: Sun May 22, 2005 4:26 pm    Post subject: Endianity with Linux on Itanium hardware Reply with quote

I've been asked to install Linux on HP-Itanium Hardware. Major demand of this installation is full big endian support.
As far as I know, all Linux distros for Itanium hardware precompiled with little endian support, nevertheless that Itanium processor support big endian. As well PPC version of Linux is big endian.

My question is: is it possible (even theoretically) to compile Linux to be big endian on Itanium ?
Back to top
View user's profile Send private message
yaneurabeya
Veteran
Veteran


Joined: 13 May 2004
Posts: 1754
Location: Seattle

PostPosted: Sun May 22, 2005 8:07 pm    Post subject: Reply with quote

I thought all Intel hardware ran big endian based number crunching, etc. However, I could be wrong...
Back to top
View user's profile Send private message
Redhatter
Retired Dev
Retired Dev


Joined: 20 Sep 2003
Posts: 548
Location: Brisbane, QLD, Australia

PostPosted: Sun May 22, 2005 11:38 pm    Post subject: Reply with quote

Actually no... Intel IA32 (x86) is little endian... as is AMD64.

I've had a look around... everything I've found regarding IA64 mentions it being little endian... I'm doubtful as to whether IA64 can even run Big Endian.

Some arches can run both ways... MIPS is one... on SGI machines, the CPUs are generally configured big endian, and on Cobalt servers, little endian. In this case though, you need a different userland and compiller...

You'll notice that Cobalt servers use "mipsel-unknown-linux-gnu" as a CHOST, vs "mips-unknown-linux-gnu" on SGI machines... Guess what the "el" stands for... :-)

I think you'd find, if it were possible, it would be a similar situation with IA64... although I'm no expert in the area, having never used it.
_________________
Stuart Longland (a.k.a Redhatter, VK4MSL)
I haven't lost my mind - it's backed up on a tape somewhere...

Gentoo/MIPS Cobalt developer, Mozilla herd member.
Back to top
View user's profile Send private message
emilsa
n00b
n00b


Joined: 22 May 2005
Posts: 2

PostPosted: Mon May 23, 2005 7:09 am    Post subject: Reply with quote

Actually all world running big endian. Only Intel uses little endian.
Itanium for sure running both: HP-UX on Itanium servers run big endian and Linux - little endian. CPU endianity controlled by boot loader.

My question is if it is possible to compile Linux for Itanium as big endian system ?
Back to top
View user's profile Send private message
Redhatter
Retired Dev
Retired Dev


Joined: 20 Sep 2003
Posts: 548
Location: Brisbane, QLD, Australia

PostPosted: Mon May 23, 2005 1:49 pm    Post subject: Reply with quote

Ahh okay, so the bootloader is able to switch the CPU into either mode. Therefore, yes, it definately should be possible, given an appropriate kernel and userland. (or cross-compiler to generate the said kernel and userland).

And to clarify... there's many more architectures than just Intel that use Little Endian. MIPS can be either (as I said before)... I'm pretty sure AMD64 is little-endian too... and I'm not sure about other architectures. I know for a definite fact, that PowerPC and Sparc are definately big endian.
_________________
Stuart Longland (a.k.a Redhatter, VK4MSL)
I haven't lost my mind - it's backed up on a tape somewhere...

Gentoo/MIPS Cobalt developer, Mozilla herd member.
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Gentoo on Alternative Architectures All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum