Date: Mon, 03 Dec 2007 21:27:40 -0800 From: Julian Elischer <julian@elischer.org> To: Marcel Moolenaar <xcllnt@mac.com> Cc: FreeBSD Current <current@freebsd.org> Subject: Re: remote gdb failures in recent builds (last 6 months or so.) Message-ID: <4754E54C.20104@elischer.org> In-Reply-To: <A3A1F0CB-CF92-4D42-8211-241A561D2130@mac.com> References: <4754D411.6060608@elischer.org> <A3A1F0CB-CF92-4D42-8211-241A561D2130@mac.com>
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Marcel Moolenaar wrote: > > On Dec 3, 2007, at 8:14 PM, Julian Elischer wrote: > >> >> Here's a trace of kgdb attempting to sync with a kernel over the >> serial port.. >> >> note that: >> 1/ gdb CAN read the damned data.. this is obtained from ktrace. >> 2/ it prints out the packet in the error message. >> 3/ teh kernel is sending each message twice, in pairs. >> 4/ after kgdb finally sends a '-' (NAK) teh kernel sends ONE MORE >> which seems to be accepted >> >> Anyone have any clues? > > Works just fine for me on all platforms, but I always use uart(4). > > What platform are you using and what gdb? > How's the serial connection; through a comm-server? > What's the line setting, which driver? sio driver on Dell 2650 running new x86 kernel.. standard com1-com2 type ports. Both systems as installed from source. (-current plus or minus a month) null-modem seraial cable between the ports. port on target is sio1. flags are 0xc0 (reserve for gdb and use for gdb). trace in previous mail is extracted from gdb via ktrace, so it is getting all the bytes but somehow failing to process them. It's slowly been getting worse (across many pairs of machines) over the last few years. finally today it just doesn't work at all. I've used this pair of machines many times before. usually it takes "luck" to get synced up but once it's synced, it's solid. >
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