Yes, they were set to numbers which do not conflict with OSF/Linux/WinNT.
A PALcall instuction is coded as cmd (6 bits) = 0, number (26 bits). There are two ways of calling PALcode: A direct way, where a certain address is called, or an indirect way, which must examine the calling instruction to jump to the right place.
All L4Alpha PALcalls are located at the end of direct-callable PALcalls, hence they are fast and do not conflict with any other system
Seb
-----Original Message----- From: Daniel Potts [mailto:danielp@cse.unsw.edu.au] Sent: Dienstag, 22. Januar 2002 09:50 To: Goswin Brederlow Cc: l4-hackers@os.inf.tu-dresden.de Subject: Re: L4/Alpha palcodes
On 22 Jan 2002, Goswin Brederlow wrote:
Hi,
I hope this is the right place, havent read anything here for ages.
I was wondering whether the palcodes used by L4 on Alpha
are disjunct
to the ones used by OSF / BSD / Linux.
yes they are. An exception is l4_whoami which is an experimental syscall anyway. I think it maps directly to the OSF whoami call.
If not could they be made disjunct?
The idea I have in mind is to make a module for linux that
catches the
L4 syscalls and throws them back into user-space. That way a L4 environment could be setup within linux. It would be much like user-space-linux and would save a lot of reboots just to test out a few bytes of code.
heh :) That would be an interesting project. I'd be interested to know how (if) you will deal with device drivers, memory etc.
On the other hand, inside L4 you could do the same with OSF / BSD / Linux syscalls and thus run their binaries under L4. (You
want to run
Netscape under L4? Or Mathematica? Or something as simple as xemacs and gcc?)
A l4-linux for alpha would also need those changes (if any)
I believe.
Yes that is how we would run unmodified Linux/Alpha binaries on L4..
Cheers, Daniel
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