Date: Thu, 19 Nov 1998 13:25:40 +0200 (SAT) From: Robert Nordier <rnordier@nordier.com> To: rock@cs.uni-sb.de (D. Rock) Cc: rnordier@nordier.com, freebsd-current@FreeBSD.ORG Subject: Re: /boot/loader & comconsole Message-ID: <199811191125.NAA05575@ceia.nordier.com> In-Reply-To: <3653F2AA.D3A7CA29@cs.uni-sb.de> from "D. Rock" at "Nov 19, 98 11:27:54 am"
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D. Rock wrote: > Robert Nordier schrieb: > [...] > > One difference between boot loader and the old/new boot blocks, is > > that boot loader uses PC BIOS services (int 0x14) for comms; both > > lots of boot blocks do direct port I/O, instead. > > > > The trouble with using the BIOS is that the int 0x14 services (which > > tend to be used only to talk to serial printers under DOS) expect to > > do hardware handshaking. > Using the BIOS for configuring the serial ports gives you also only > 9600 bps. I usually ran the comconsole at 19200 bps. But the original > BIOS int 0x14 services seem only support up to 9600 bps. I did a > small patch on the bootblocks, so that it uses the "extended communication > port control" service. I don't know if good ole 386 BIOS implement this > routine, but it works on my machine (I think it was introduced with the > PS/2 PCs). I'm not sure, either, how many BIOSes support this. The documentation I have suggests it is PS/2-specific, though it appears it's supported on at least some of the machines here. > With this service I could go up to 19200 bps (wow! but my terminal can't > do more, though). I haven't noticed any problems, but now my console is > twice as fast (I sometimes even do some work on the terminal) > > Below is the small patch Thanks. If we're going to stick with using the BIOS, it seems worthwhile to allow this as an option. -- Robert Nordier To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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