From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mario Smarduch Date: Fri, 15 Nov 2002 16:11:56 +0000 Subject: Re: [Linux-ia64] One little, two little, three little endian... Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org David Mosberger wrote: > Hi Gavin, > > >>>>> On Thu, 14 Nov 2002 16:52:13 -0800, "Gavin Scott" said: > > Gavin> Hello list, I want a big endian version of Linux for IPF. > Gavin> Just how crazy am I? > > Very! ;-) > > Seriously though: running big-endian processes is the easy part, the > hard part is developing (& maintaining) big-endian versions of all > libraries. Not only is it a lot of work, but it would also fragment > the ia64 linux market, so I'd consider it a Bad Thing (TM). > > Gavin> Of course both MPE/iX and HP-UX are big-endian environments, > Gavin> and many of the people I talk to would be very interested in > Gavin> having an endian-compatible Linux that would run on big > Gavin> (i.e. IA-64) HP servers. For this group, x86 compatibility > Gavin> is probably a non-issue. > > It would be a lot easier to add an hp-ux compatibility layer on top of > ia64 linux. The layer would emulate the (big-endian) hp-ux system > calls and then you would install the big-endian hp-ux libraries on top > of that (e.g., in the /emul/ia64-hpux/ tree). Of course, I'm ignoring > legal issues here as copying the hp-ux libraries would presumably > require some sort of license. But legal issues aside, this is doable > and has been done many times before (e.g., alpha linux can run (some) > Tru64 binaries, sparc linux can run sunos/solaris(?) binaries, etc.). David a quick question. Even though the library problem is overcomed, how would signal handling be accomplished by an application running in big-endian. Doesn't the kernel fill in the siginfo and context while runing in little endian? - Mario. > > > Gavin> I'm interested in any comments that come to mind. I'm most > Gavin> interested in just how complex the task would be from a > Gavin> technical point of view, either to make the system buildable > Gavin> either way, or possibly supporting a per-process endian bit > Gavin> (which would be cool, but probably a lot more work). > > Actually, adding a per-process endian bit would be easy. In fact, > even without, a little-endian program can turn on the big-endian bit > as long as it's prepared to deal with the consequences. The hard part > is really the libraries. > > --david > > _______________________________________________ > Linux-IA64 mailing list > Linux-IA64@linuxia64.org > http://lists.linuxia64.org/lists/listinfo/linux-ia64