freebsd-hackers Digest, Vol 588, Issue 1
Nidal Khalil
nedmath at gmail.com
Tue Jul 22 21:30:40 UTC 2014
Hello All,
OK, I was able to capture the early boot output by entering ddb
GDB: no debug ports present
KDB: debugger backend; ddb
My pc does not have a serial port. However I am using usb to serial by
Prolific Tech.
You mean to tell me that the kernel gdb shim is hardwired to /dev/cuau0?
Nidal
On Tue, Jul 22, 2014 at 2:06 PM, Nidal Khalil <nedmath at gmail.com> wrote:
> Still no go
>
>
> On Tue, Jul 22, 2014 at 5:00 AM, <freebsd-hackers-request at freebsd.org>
> wrote:
>
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>> Today's Topics:
>>
>> 1. Remote kernel debugging question (Nidal Khalil)
>> 2. Re: Remote kernel debugging question (Benjamin Kaduk)
>> 3. Re: Remote kernel debugging question (Nidal Khalil)
>> 4. Re: Remote kernel debugging question (Navdeep Parhar)
>> 5. Re: Remote kernel debugging question (Nidal Khalil)
>> 6. Re: Remote kernel debugging question (Navdeep Parhar)
>> 7. Re: Remote kernel debugging question (Nidal Khalil)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Mon, 21 Jul 2014 12:22:59 -0700
>> From: Nidal Khalil <nedmath at gmail.com>
>> To: freebsd-hackers at freebsd.org
>> Subject: Remote kernel debugging question
>> Message-ID:
>> <
>> CADoY-6j0d9pBn-TDoMf5gysE8QiGz42DCFGLDWASig-wqLiMbg at mail.gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> 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
>> How do I enable gdb backend. I appreciate the help.
>>
>> Nidal
>>
>>
>> ------------------------------
>>
>> Message: 2
>> Date: Mon, 21 Jul 2014 17:55:51 -0400 (EDT)
>> From: Benjamin Kaduk <bjk at freebsd.org>
>> To: Nidal Khalil <nedmath at gmail.com>
>> Cc: freebsd-hackers at freebsd.org
>> Subject: Re: Remote kernel debugging question
>> Message-ID: <alpine.GSO.1.10.1407211754470.21571 at multics.mit.edu>
>> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
>>
>> On Mon, 21 Jul 2014, 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
>> > How do I enable gdb backend. I appreciate the help.
>>
>> I do not think I have actually used remote GDB kernel debugging on my own
>> machines, but I wanted to make sure that you had seen the documentation
>> for doing so, available at
>>
>> http://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug-online-gdb.html
>> . If it is incorrect, we should update it to be correct.
>>
>> Thanks,
>>
>> Ben Kaduk
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Mon, 21 Jul 2014 14:58:24 -0700
>> From: Nidal Khalil <nedmath at gmail.com>
>> To: Benjamin Kaduk <bjk at freebsd.org>
>> Cc: freebsd-hackers at freebsd.org
>> Subject: Re: Remote kernel debugging question
>> Message-ID:
>> <
>> CADoY-6hcD6ACwFVgX-LJ2cXHL35-bO+F8NYZ69vf3VDpg0DAAA at mail.gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> Hi Ben,
>> Yes I am familiar with the doc. As
>>
>>
>> On Mon, Jul 21, 2014 at 2:55 PM, Benjamin Kaduk <bjk at freebsd.org> wrote:
>>
>> > On Mon, 21 Jul 2014, 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
>> >> How do I enable gdb backend. I appreciate the help.
>> >>
>> >
>> > I do not think I have actually used remote GDB kernel debugging on my
>> own
>> > machines, but I wanted to make sure that you had seen the documentation
>> for
>> > doing so, available at http://www.freebsd.org/doc/en/
>> > books/developers-handbook/kerneldebug-online-gdb.html . If it is
>> > incorrect, we should update it to be correct.
>> >
>> > Thanks,
>> >
>> > Ben Kaduk
>> >
>>
>>
>> ------------------------------
>>
>> Message: 4
>> Date: Mon, 21 Jul 2014 15:22:32 -0700
>> From: Navdeep Parhar <nparhar at gmail.com>
>> To: Nidal Khalil <nedmath at gmail.com>, freebsd-hackers at freebsd.org
>> Subject: Re: Remote kernel debugging question
>> Message-ID: <53CD92A8.5000201 at gmail.com>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> 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
>>
>>
>> ------------------------------
>>
>> Message: 5
>> Date: Mon, 21 Jul 2014 15:35:01 -0700
>> From: Nidal Khalil <nedmath at gmail.com>
>> To: Navdeep Parhar <nparhar at gmail.com>
>> Cc: freebsd-hackers at freebsd.org
>> Subject: Re: Remote kernel debugging question
>> Message-ID:
>> <
>> CADoY-6hPgy8e7ETt2bFM27P--PJTjSTX0e9+bo3aVE4UyweYEw at mail.gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> The documentation states to put hint.uart.0.flags="0x90" in
>> /boot/device.hits
>> 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
>>
>> Nidal
>>
>>
>> On Mon, Jul 21, 2014 at 3:22 PM, Navdeep Parhar <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
>> >
>>
>>
>> ------------------------------
>>
>> Message: 6
>> Date: Mon, 21 Jul 2014 15:40:09 -0700
>> From: Navdeep Parhar <nparhar at gmail.com>
>> To: Nidal Khalil <nedmath at gmail.com>
>> Cc: freebsd-hackers at freebsd.org
>> Subject: Re: Remote kernel debugging question
>> Message-ID: <53CD96C9.2010600 at gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> 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
>> >
>> >
>>
>>
>>
>> ------------------------------
>>
>> Message: 7
>> Date: Mon, 21 Jul 2014 15:44:23 -0700
>> From: Nidal Khalil <nedmath at gmail.com>
>> To: Navdeep Parhar <nparhar at gmail.com>
>> Cc: freebsd-hackers at freebsd.org
>> Subject: Re: Remote kernel debugging question
>> Message-ID:
>> <
>> CADoY-6hJUGOvhQ6qoeP1aYLZ737dgYQGSsik_QF1+qXqcPH1Nw at mail.gmail.com>
>> Content-Type: text/plain; charset=UTF-8
>>
>> 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
>> > >
>> > >
>> >
>> >
>>
>>
>> ------------------------------
>>
>> Subject: Digest Footer
>>
>> _______________________________________________
>> freebsd-hackers at freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
>> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe at freebsd.org
>> "
>>
>> ------------------------------
>>
>> End of freebsd-hackers Digest, Vol 588, Issue 1
>> ***********************************************
>>
>
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