Return to BSD News archive
Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!haven.umd.edu!uunet!Germany.EU.net!mcsun!news.funet.fi!hydra!klaava!klaava!not-for-mail From: torvalds@klaava.Helsinki.FI (Linus Torvalds) Newsgroups: comp.os.386bsd.bugs Subject: Re: Nethack Date: 7 Jul 1993 14:51:29 +0300 Organization: University of Helsinki Lines: 21 Message-ID: <21edc1$buu@klaava.Helsinki.FI> References: <21678c$13q@klaava.Helsinki.FI> <216rcfINNj4@fstgds01.tu-graz.ac.at> <2192jh$njf@klaava.Helsinki.FI> <C9oxs9.H4D@sugar.neosoft.com> NNTP-Posting-Host: klaava.helsinki.fi In article <C9oxs9.H4D@sugar.neosoft.com> peter@NeoSoft.com (Peter da Silva) writes: >In article <2192jh$njf@klaava.Helsinki.FI> torvalds@klaava.Helsinki.FI (Linus Torvalds) writes: >> Yep. Again, linux uses a slightly different way of handling copyin/out >> by simply doing it with inline assembly from the %fs segment, which >> points to user space when doing system calls. > >What does the 68030 version do? This particular issue shouldn't be a porting problem: while it used the %fs segment to get and put user data, it's all hidden behind inline functions, so it should be easy to compensate for any special mm behaviour. I haven't looked into the 68k port, but if I understood correctly from the limited reading of the mailing list, the 68030 and higher memory managers also use segments for this kind of thing (not the same way the x86 machines do, but still), and that the linux way of handling it actually mapped well to the 68k family (using 'movec' instead of 'mov %fs:xxx' or something similar). I have only programmed the 68k in the earlier models that didn't support memory management, so I don't know the details myself. Linus