Date: Mon, 5 Jan 2004 22:34:04 +1100 (EST) From: Bruce Evans <bde@zeta.org.au> To: Bruce M Simpson <bms@spc.org> Cc: nate@root.org Subject: Re: Serial console only works after reboot? Message-ID: <20040105215501.M5112@gamplex.bde.org> In-Reply-To: <20040105071321.GA63069@saboteur.dek.spc.org> References: <20040103233044.N17367@root.org> <20040104.003330.54786488.imp@bsdimp.com> <20040104.164103.03383403.imp@bsdimp.com> <20040105162219.A3687@gamplex.bde.org> <20040105071321.GA63069@saboteur.dek.spc.org>
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On Mon, 5 Jan 2004, Bruce M Simpson wrote: > On Mon, Jan 05, 2004 at 04:50:13PM +1100, Bruce Evans wrote: > > It should use BOOT_COMCONSOLE_PORT and BOOT_CONSOLE_SPEED like boot2 > > does. > > Ideally, yes. However an assembly language macro would be needed to stuff > the appropriate divisor value into the BIOS call used to set the speed. There > are hardly any bytes free in boot0; I had to shave strings to get enough > space as it is. There are also hardly enough bits in the BIOS interface. It has a whole 3 bits to encode the speed and is limited to 9600 bps. > Doing sio directly bypassing the BIOS would require that the MBR be enlarged > to 1024, rather than 512, bytes. This is one of the issues I originally had > with the code being imported as-is however obrien was happy to take it anyway. Probably, but direct access only takes a few more bytes (20-30 altogether). A feature could be left out to make room. (The boot0 that I use has a completely different feature set.) Bruce
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