From: Christoph Plattner <[EMAIL PROTECTED]>
Subject: Re: Grub over serial line - status ! (I did a test version, itruns!)
Date: Thu, 13 Apr 2000 09:39:13 +0200
> In the first moment, I also thought, that autodetection is the only
> solution. But on the other hand, if I consider, that GRUB in a
> networked embedded environment can load the 'menu.lst' from the ethernet
> (diskless operation, perhaps also in a normal operation !!), that
> it is convinient to decide sitting on the host, if a machine should
> use vga or serial line.
That's right. If a machine connects a network, it is the easiest way
to put a configuration file on a server and download it. So I believe
that controlling the behavior in a configuration file is basically
right.
For now, I think this scheme is the best:
1. If you can give every GRUB machine one configuration file per
machine or simply they can share one configuration file, there is no
problem; You should write as many configuration files as necessary.
2. If multiple machines must share one configuration file as Tim
suggested, you should enable both a screen console and a serial
console by "console screen com0". Then GRUB should probe them and wait
for the user's input. If the input comes from the screen, GRUB should
use the screen subsequently. If the input comes from the serial port,
GRUB should use the serial console.
> There is a big advantage of using BIOS code for the serial line, as I
> did in my first test-implementation. The UART is configured in a way,
> that it only transmits data, if the hardware handshake lines are
> asserted.
> It is not possible, to change this on bios support. Also all M$ systems
> use the UART in this mode. (I mean, you also must assert this handshake
> lines, although 'NO HARDWARE HANDSHAKING' is configured).
??? I can't see what you mean. Can you give me more hints?
> For all such possibilities, a own UART handling instead of BIOS is
> necessary. I also don't know, who to configure the serial line for
> more than 9600baud with bios calls.
Didn't you see INT 14 AH=04h? Nowadays, nearly all BIOSes can set it
to 19200bps.
> Question:
> Is there a documentation of all BIOS calls.
> My docus are very old from 8086 and 80286 system.
> Is there anywhere a current one ?
Ralf Brown's interrupt list (the URL is below) will give you good
resources. It contains descriptions for most BIOS calls.
http://www.cs.cmu.edu/afs/cs.cmu.edu/user/ralf/pub/WWW/files.html
Of course, there are official documents by IBM, Phoenix, Microsoft,
and some others.
> Is there a docu concerning the terminal standards
> ANSI, VT100, VT102, VT52
> not to implement something else as the standards !
The Linux Text-Terminal-HOWTO is a good start point:
http://www.linuxdoc.org/HOWTO/Text-Terminal-HOWTO.html
Okuji
