From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Knorr Subject: Re: VGA extended text modes Date: 28 Feb 2005 18:25:46 +0100 Message-ID: <87wtss1tr9.fsf@bytesex.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: xen-devel-admin@lists.sourceforge.net Errors-To: xen-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Ian Pratt Cc: Jared Rhine , xen-devel@lists.sourceforge.net, ian.pratt@cl.cam.ac.uk List-Id: xen-devel@lists.xenproject.org "Ian Pratt" writes: > However, how does dom0 set the extended text mode? I presume it doesn't > use a BIOS call. Linux uses vesa bios calls in the 16bit startup code, at least for the stuff settable via vga="...". Mode info is passed to 32bit code in struct screen_info (see Documentation/i386/zero-page.txt). Thats why the vga argument needs special treatment by the boot loaders, they can't just pass it on on the kernel command line like most other args. They have to set a byte in the kernel's boot sector for that. See also "man rdev". That is really old stuff from the days you have booted your new linux kernel using "cat zImage > /dev/fd0 && reboot". For just more text lines you can simply load a smaller font than the default one somewhere in the dom0 boot scripts to have the same effect. That doesn't work for 132col txt modes or graphic modes (=> vesafb) though. Gerd -- #define printk(args...) fprintf(stderr, ## args) ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click