Date: Wed, 1 Nov 2006 13:59:04 +1100 From: Andrew Reilly <andrew-netbsd@areilly.bpc-users.org> To: "Brian A. Seklecki" <lavalamp@spiritual-machines.org> Cc: freebsd-questions@freebsd.org, netbsd-users@netbsd.org Subject: Re: Hardware Console Redirection Message-ID: <20061101025904.GA30503@duncan.reilly.home> In-Reply-To: <20061031175606.P63561@arbitor.digitalfreaks.org> References: <20061031175606.P63561@arbitor.digitalfreaks.org>
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On Tue, Oct 31, 2006 at 06:18:22PM -0500, Brian A. Seklecki wrote: > I have noticed that the "Phoenix BIOS" console redirection feature on both > discontinues to operate once the kernel has booted (however, the 1st/2nd > stage boot loaders work fine). Why is that a problem? The BIOS doesn't use the console once the kernel has booted. > The advantage of native, hardware level BIOS -> VGA emulated console > redirection is that, much like Sun/MacPPC or any OPF/PROM aware platform > (Soekris), the OS/Bootblocks need not be aware of the serial console > semantics; -- only of a benign VGA console. What serial console semantics do the bootblocks get wrong? > Is there some routine in the *BSD kernel console code that performs an > operation, perhaps a reset, on the serial ports, that wouldn't happen in > DOS? What sort of reset do you need? I don't really understand the question, I'm afraid. Do you mean a hardware reset of the serial port, or using the serial port to have the effect of Ctl-Alt-Delete (NMI) from a PC keyboard? > In the case of the Axiom device, the console is redirected to the BIOS > level "com0" 0x3f8. In the case of the PowerEdge, the redirection is to a > "virtual com1" which is attached to the DRAC5 LOM card. > > I tried the FreeBSD loader(8) hint.sio.1.flags="0x40" to attempt to have > the kernel ignore the device without success. You can build a kernel that explicitly doesn't have a driver that will look at a particular serial port, I think (by making it explicit which ports it *does* look at), but I don't understand how that would help: you'd have a serial port that would be used by the BIOS, but would do nothing once the main OS was booted. Cheers, -- Andrew
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