Date: Fri, 19 Dec 1997 10:19:42 -0800 From: Amancio Hasty <hasty@rah.star-gate.com> To: Bruce Evans <bde@zeta.org.au> Cc: current@freebsd.org, gjp@erols.com, gjp@erols.net, pb@fasterix.freenix.org Subject: Re: cvs commit: src/sys/i386/linux linux.h linux_ioctl.c Message-ID: <199712191819.KAA02040@rah.star-gate.com> In-Reply-To: Your message of "Sat, 20 Dec 1997 04:52:10 %2B1100." <199712191752.EAA21467@godzilla.zeta.org.au>
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Yes, I know the way that I implemented it. Tnks. We can go via the iobitmap method after a short test cycle . --- Two problem still remain with the linux layer : the treatment of virtual consoles and mmap. Regards, Amancio > >I know what ioperm does and I first implemented it for 386bsd 0.0 8) > > That was more like Linux iopl than Linux ioperm. Linux iopl is already > implemented (incorrectly) in the Linux emulator. In Linux, it sets > the iopl bitfield to the specified value (0-3). In the Linux emulator, > it always sets the iopl bitfield to 3. > > >Not sure if it is worth any hazzle to implement it the way that > >that svgalib uses it . The problem comes in when they want to > > There is no choice. Anything else would not be Linux compatible. > > >do any kind of video acceleration how to then enable all those > >i/o registers for something like an S3 chipset. > > Svgalib presumably uses iopl for the hard cases. Linux has a restriction > on the bitmap size, at least in old versions, so it may be impossible to > access all the registers using ioperm. FreeBSD VM86-ioperm doesn't have > this restriction. > > >At any rate, there may be other valid uses for ioperm other than > >for svgalib. > > Linux ioperm gives some chance of secure access to device registers. > It needs at least a big immutable database of which registers are > secure. Where are all those i/o registers in your graphics card today? > > Bruce
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