Date: Sun, 28 Dec 1997 16:56:06 +1030 From: Greg Lehey <grog@lemis.com> To: Chris Timmons <skynyrd@opus.cts.cwu.edu> Cc: Bruce Evans <bde@zeta.org.au>, julian@whistle.com, freebsd-current@FreeBSD.ORG Subject: Re: Remote gdb (was: no boot: config -g and options DDB) Message-ID: <19971228165606.13142@lemis.com> In-Reply-To: <Pine.BSF.3.96.971227215431.8511C-100000@opus.cts.cwu.edu>; from Chris Timmons on Sat, Dec 27, 1997 at 10:06:09PM -0800 References: <19971228161844.52116@lemis.com> <Pine.BSF.3.96.971227215431.8511C-100000@opus.cts.cwu.edu>
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On Sat, Dec 27, 1997 at 10:06:09PM -0800, Chris Timmons wrote: > On Sun, 28 Dec 1997, Greg Lehey wrote: > >>> Are you sure it chooses the first sio with flags 0x10, or does the first >>> boot prompt get squirted out all eligible sio units? >> >> It's in sioncprobe(), the function for which Bruce supplied the >> patches. It goes out and looks for the first "enabled" console, does >> its thing and breaks out of the loop. Its thing includes setting the >> variable siocniobase, which is used by the other serial console >> routines to specify the output port. >> >> This stuff's pretty basic. Don't expect it to be clever enough to >> maintain the pressure in multiple pipes :-) > > Hmmm - well allow me to babble some more when I should instead be UTS. > > Is it the case then that flags 0x50 is presently just a hush for the > serial console (i.e. you have to have both flags on the same unit and > couldn't have sio0 with flags 0x10 and sio1 with flags 0x40 - preserving a > serial console at sio0 while debugging on sio1.) Well, I've never used the 0x40 bit. According to the documentation, it's for "Low-Level" serial communication, and it appears to work by not creating the device if it's specified. It might be the way that it was intended: boot with -h to set the serial hardware, and then disconnect the serial console again after the boot message. It does work, anyway. Bruce's patch makes more sense. > How would you start the debugger at boot on an sio with flags 0x40? > I remember seeing Bruce's commit messages about this so I can go > back and look. I've just tried it with flags 0x50, and it works fine. I still think it's a bit superfluous, but it would help protect the gdb port from other activities. Greg
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