Remote kernel debugging question

[Nidal Khalil]

No, I have not .
It is hint.uart.0.flags="0x90"
Thanks
My question is how do I get gdb to show up as part of available debuggers
in this node:
debug.kdb.available: ddb
Thanks

Nidal


On Mon, Jul 21, 2014 at 3:40 PM, Navdeep Parhar <nparhar at gmail.com> wrote:

> 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 at gmail.com
> > <mailto:nparhar at 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
> >
> >
>
>