Date: Mon, 21 Jul 2014 15:40:09 -0700 From: Navdeep Parhar <nparhar@gmail.com> To: Nidal Khalil <nedmath@gmail.com> Cc: freebsd-hackers@freebsd.org Subject: Re: Remote kernel debugging question Message-ID: <53CD96C9.2010600@gmail.com> In-Reply-To: <CADoY-6hPgy8e7ETt2bFM27P--PJTjSTX0e9%2Bbo3aVE4UyweYEw@mail.gmail.com> References: <CADoY-6j0d9pBn-TDoMf5gysE8QiGz42DCFGLDWASig-wqLiMbg@mail.gmail.com> <53CD92A8.5000201@gmail.com> <CADoY-6hPgy8e7ETt2bFM27P--PJTjSTX0e9%2Bbo3aVE4UyweYEw@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 07/21/14 15:35, Nidal Khalil wrote: > The documentation states to put hint.uart.0.flags="0x90" in > /boot/device.hits Putting it in device.hints should have worked too. In fact, that's where uart(4) has it. You haven't spelled it "hits" on your filesystem like you did here, have you? > However you hit on a good point. I see some parameters in > boot/loader.conf. Can you please email this file > I think that I need to do more configuration to this file. I will do it > by comparison. Thanks That's all there was in the file. Regards, Navdeep > > Nidal > > > On Mon, Jul 21, 2014 at 3:22 PM, Navdeep Parhar <nparhar@gmail.com > <mailto:nparhar@gmail.com>> wrote: > > On 07/21/14 12:22, Nidal Khalil wrote: > > Hello All, > > I am somewhat new to BSD kernel but I am trying to debug a kernel > module > > using remote debugging. > > I am using 9.2 RELEASE. > > I setup and compiled the kernel with the following: > > > > makeoptions DEBUG=-g > > options KDB > > options KDB_TRACE > > options DDB_CTF > > options DDB > > options GDB > > options ALT_BREAK_TO_DEBUGGER > > > > I setup the uart for serial1 flags to 0x90 and I can read and > write to the > > serial from either machine > > Both machines have the same kernel booted. > > I can enter ddb but I can not launch gdb > > The remote GDB backend could not be selected. > > sysctl -a | grep debug.kdb > > > > debug.kdb.available: ddb > > Is that correct or it should be: > > debug.kdb.available: ddb gdb > > The latter. > > > How do I enable gdb backend. I appreciate the help. > > All this on a recent HEAD. If your problem is 9.2 specific then this > may not help, but at least we can compare notes. You did say you set > flags to 0x90 for your serial port but it's not clear how. I have this > in /boot/loader.conf: > hint.uart.0.flags="0x90" > > When the system boots I see this right around when loader hands off to > the kernel. > > GDB: debug ports: uart > GDB: current port: uart > KDB: debugger backends: ddb gdb > KDB: current backend: ddb > Copyright (c) 1992-2014 The FreeBSD Project. > ... > > After the system boots I see both ddb and gdb in the available debug > backends and all is well. > > # sysctl debug.kdb.available > debug.kdb.available: ddb gdb > # sysctl debug.kdb.current > debug.kdb.current: ddb > # sysctl debug.kdb.current=gdb > debug.kdb.current: ddb -> gdb > # sysctl debug.kdb.current > debug.kdb.current: gdb > > Regards, > Navdeep > >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?53CD96C9.2010600>