Re: [edk2] Source code debugging of OVMF

[Johannes Swoboda]

Hello Brian,

Unfortunately, if I understand it correctly, this page explains how to 
debug efi-apps (where gdb can simply load the efi-file to load the 
symbols), but this isn't applicable for the ovmf.fd-file itself; gdb 
refuses to open it.


However, this will be of help when I'll look at an efi app.

Thank you and kind regards, Johannes

On 2018-04-16 17:26, Richardson, Brian wrote:

This page was recently added to the TianoCore wiki. Please let me know
if this is useful info:
https://github.com/tianocore/tianocore.github.io/wiki/How-to-debug-OVMF-with-QEMU-using-GDB

Thanks ... br
---
Brian Richardson, Senior Technical Marketing Engineer, Intel Software
brian.richard...@intel.com -- @intel_brian (Twitter & WeChat)
https://software.intel.com/en-us/meet-the-developers/evangelists/team/brian-richardson

-Original Message-
From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of
Johannes Swoboda
Sent: Monday, April 16, 2018 7:09 AM
To: edk2-devel@lists.01.org
Cc: clemens.hlausc...@inso.tuwien.ac.at
Subject: [edk2] Source code debugging of OVMF

Hello everyone,

I'm doing a research project on efi security. I would like to do
source code debugging of OVMF. I want to step through the OVMF source
code, set break points, et cetera, preferably with gdb. I want to
debug the overall boot process. Is that possible?

I understand I can start qemu with the options -s -S. This gives me a
virtual machine that awaits connection of a gdb debugger and further
instructions.

After connecting with gdb, I can instruct the machine to continue
execution. Unsurprisingly, there is nothing else I can do, because gdb
lacks the relevant symbols.
I tried to read in the OVMF.fd file, as i would do with a binary that
I would debug, but gdb can't handle the file.
It seems to be possible to load an efi app with the file command, but
not this one.

I found one other person trying to achieve the same five years ago.
[3] suggests that something like this

(gdb) add-symbol-file ../edk2/Build/OvmfX64/DEBUG_GCC5/X64/Shell.debug
The address where ../edk2/Build/OvmfX64/DEBUG_GCC5/X64/Shell.debug has
been loaded is missing

might be possible. However, it appears to me this is may contain
information regarding Shell.efi, an efi-app; but I don't want to debug
an app. I want to debug the overall boot process.

I'm quoting some terminal output to clarify what I'm trying to achieve:
[johannes@johannes-laptop OVMF_efi_hello_world]$ gdb [...]
(gdb) file OVMF.fd
"/home/johannes/18S/bakk/uefi_virtual/OVMF_efi_hello_world/OVMF.fd":
not in executable format: File format not recognized
(gdb) target remote localhost:1234
Remote debugging using localhost:1234
warning: No executable has been specified and target does not support
determining executable automatically.  Try using the "file" command.
0xfff0 in ?? ()
(gdb) step
Cannot find bounds of current function
(gdb) list
No symbol table is loaded.  Use the "file" command.
(gdb) continue
Continuing.
[ovmf loads in qemu window]

I can redirect ovmf debug messages into a text file[1].
As far as I understand, there is a way to do source code level 
debugging

*with* ovmf, to debug efi-apps that are e.g. run via the efi shell[2],
with the help of SourceLevelDebugPkg[4], but this package cannot be
used to source level debug the overall boot process, right?

Is it possible to do source level debugging of ovmf?
Is it possible to step through ovmf, one instruction or function call 
at a time?

How are you ovmf developer debugging it?

If you could point me to the right direction, that would be great.

Kind regards,
Johannes

[1]: I managed to do so via the qemu options -global
isa-debugcon.iobase=0x402 -debugcon file:qemu.ovmf.log" as
demonstrated here
https://www.linux-kvm.org/downloads/lersek/ovmf-whitepaper-c770f8c.txt
[2]:https://github.com/tianocore/tianocore.github.io/wiki/OVMF-FAQ#how-do-i-enable-source-level-debugging-with-ovmf
[3]:
http://edk2-devel.narkive.com/LRWe2mSQ/using-gdb-on-ovmf-with-symbols
[4]:
https://github.com/tianocore/tianocore.github.io/wiki/SourceLevelDebugPkg

___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Re: [edk2] Source code debugging of OVMF

[Laszlo Ersek]

On 04/19/18 04:46, Rebecca Cran wrote:
> On 04/16/18 12:25, Rebecca Cran wrote:
>> On 04/16/18 10:13, Laszlo Ersek wrote:
>>
>>> Here's another thread that you might find useful:
>>>
>>> http://edk2-devel.narkive.com/6BRVus92/qestion-about-how-to-debug-ovmf-on-qemu
>>
>> I should get my Phabricator wiki running again, which has a
>> nicely-formatted version of that - I haven't set it up again after
>> moving systems.
>>
> 
> https://code.bluestop.org/w/tianocore/debugging-with-gdb/ is now working
> again.
> 

Thank you!
Laszlo
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Re: [edk2] Source code debugging of OVMF

[Rebecca Cran]

On 04/16/18 12:25, Rebecca Cran wrote:
> On 04/16/18 10:13, Laszlo Ersek wrote:
> 
>> Here's another thread that you might find useful:
>>
>> http://edk2-devel.narkive.com/6BRVus92/qestion-about-how-to-debug-ovmf-on-qemu
> 
> I should get my Phabricator wiki running again, which has a
> nicely-formatted version of that - I haven't set it up again after
> moving systems.
> 

https://code.bluestop.org/w/tianocore/debugging-with-gdb/ is now working
again.

-- 
Rebecca
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Re: [edk2] Source code debugging of OVMF

[Laszlo Ersek]

On 04/16/18 20:25, Rebecca Cran wrote:
> On 04/16/18 10:13, Laszlo Ersek wrote:
> 
>> Here's another thread that you might find useful:
>>
>> http://edk2-devel.narkive.com/6BRVus92/qestion-about-how-to-debug-ovmf-on-qemu
> 
> I should get my Phabricator wiki running again, which has a
> nicely-formatted version of that - I haven't set it up again after
> moving systems.
> 

Yes please! :)

Thanks!
Laszlo
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Re: [edk2] Source code debugging of OVMF

[Rebecca Cran]

On 04/16/18 10:13, Laszlo Ersek wrote:

> Here's another thread that you might find useful:
> 
> http://edk2-devel.narkive.com/6BRVus92/qestion-about-how-to-debug-ovmf-on-qemu

I should get my Phabricator wiki running again, which has a
nicely-formatted version of that - I haven't set it up again after
moving systems.

-- 
Rebecca
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Re: [edk2] Source code debugging of OVMF

[Palmer, Thomas]

I use Andrew WIP's stuff often as well.  Just put the GdbSyms.inf in your DSC 
(not FDF) and build.  My .gdbinit script looks like this:

set architecture i386:x86-64:intel
target remote localhost:1234
source DebugPkg/Scripts/gdb_uefi.py
reload-uefi -o 
Build/OvmfX64/DEBUG_GCC5/X64/DebugPkg/GdbSyms/GdbSyms/DEBUG/GdbSyms.dll


Andrew, I owe you a couple of beers if we ever meet.



Regards,

Thomas Palmer

"I have only made this letter longer because I have not had the time to make it 
shorter" - Blaise Pascal


-Original Message-
From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of Laszlo 
Ersek
Sent: Monday, April 16, 2018 11:14 AM
To: Johannes Swoboda 
Cc: Michael Kinney ; edk2-devel@lists.01.org; 
clemens.hlausc...@inso.tuwien.ac.at
Subject: Re: [edk2] Source code debugging of OVMF

Hi Johannes,

On 04/16/18 13:09, Johannes Swoboda wrote:

> How are you ovmf developer debugging it?

In general I add DEBUG statements, grep the tree for protocol / PPI GUIDs, and 
use an editor with good ctags support.

Here's another thread that you might find useful:

http://edk2-devel.narkive.com/6BRVus92/qestion-about-how-to-debug-ovmf-on-qemu

Occasionally I do use gdb with QEMU, but the solution I use is not suitable for 
debugging modules in the SEC and PEI phases, only in DXE. I have some terribly 
rough patches in my local tree that are based on 
<https://github.com/andreiw/andreiw-wip/tree/master/uefi/DebugPkg>.

I don't recall having any luck with SOURCE_DEBUG_ENABLE and the UDK debugger 
<https://firmware.intel.com/develop/intel-uefi-tools-and-utilities/intel-uefi-development-kit-debugger-tool>,
but admittedly it's been a while (= years?) since I last tried to connect 
debugger VM with debugge VM over a virtual serial port. Others have more 
recently confirmed it works for them. I think Mike uses it successfully, from a 
Windows debugger machine maybe?

Thanks,
Laszlo
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Re: [edk2] Source code debugging of OVMF

[Laszlo Ersek]

Hi Johannes,

On 04/16/18 13:09, Johannes Swoboda wrote:

> How are you ovmf developer debugging it?

In general I add DEBUG statements, grep the tree for protocol / PPI
GUIDs, and use an editor with good ctags support.

Here's another thread that you might find useful:

http://edk2-devel.narkive.com/6BRVus92/qestion-about-how-to-debug-ovmf-on-qemu

Occasionally I do use gdb with QEMU, but the solution I use is not
suitable for debugging modules in the SEC and PEI phases, only in DXE. I
have some terribly rough patches in my local tree that are based on
.

I don't recall having any luck with SOURCE_DEBUG_ENABLE and the UDK
debugger
,
but admittedly it's been a while (= years?) since I last tried to
connect debugger VM with debugge VM over a virtual serial port. Others
have more recently confirmed it works for them. I think Mike uses it
successfully, from a Windows debugger machine maybe?

Thanks,
Laszlo
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Re: [edk2] Source code debugging of OVMF

[Blibbet]

On 04/16/2018 08:26 AM, Richardson, Brian wrote:
>
https://github.com/tianocore/tianocore.github.io/wiki/How-to-debug-OVMF-with-QEMU-using-GDB


Also useful for this topic:

https://github.com/tianocore/tianocore.github.io/wiki/Testing-SMM-with-QEMU,-KVM-and-libvirt

HTH,
Lee
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Re: [edk2] Source code debugging of OVMF

[Richardson, Brian]

This page was recently added to the TianoCore wiki. Please let me know if this 
is useful info:
https://github.com/tianocore/tianocore.github.io/wiki/How-to-debug-OVMF-with-QEMU-using-GDB
 

Thanks ... br
---
Brian Richardson, Senior Technical Marketing Engineer, Intel Software
brian.richard...@intel.com -- @intel_brian (Twitter & WeChat)
https://software.intel.com/en-us/meet-the-developers/evangelists/team/brian-richardson
 

-Original Message-
From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of Johannes 
Swoboda
Sent: Monday, April 16, 2018 7:09 AM
To: edk2-devel@lists.01.org
Cc: clemens.hlausc...@inso.tuwien.ac.at
Subject: [edk2] Source code debugging of OVMF

Hello everyone,

I'm doing a research project on efi security. I would like to do source code 
debugging of OVMF. I want to step through the OVMF source code, set break 
points, et cetera, preferably with gdb. I want to debug the overall boot 
process. Is that possible?

I understand I can start qemu with the options -s -S. This gives me a virtual 
machine that awaits connection of a gdb debugger and further instructions.

After connecting with gdb, I can instruct the machine to continue execution. 
Unsurprisingly, there is nothing else I can do, because gdb lacks the relevant 
symbols.
I tried to read in the OVMF.fd file, as i would do with a binary that I would 
debug, but gdb can't handle the file.
It seems to be possible to load an efi app with the file command, but not this 
one.

I found one other person trying to achieve the same five years ago. [3] 
suggests that something like this
> (gdb) add-symbol-file ../edk2/Build/OvmfX64/DEBUG_GCC5/X64/Shell.debug
> The address where ../edk2/Build/OvmfX64/DEBUG_GCC5/X64/Shell.debug has 
> been loaded is missing
might be possible. However, it appears to me this is may contain information 
regarding Shell.efi, an efi-app; but I don't want to debug an app. I want to 
debug the overall boot process.

I'm quoting some terminal output to clarify what I'm trying to achieve:
[johannes@johannes-laptop OVMF_efi_hello_world]$ gdb [...]
(gdb) file OVMF.fd
"/home/johannes/18S/bakk/uefi_virtual/OVMF_efi_hello_world/OVMF.fd": not in 
executable format: File format not recognized
(gdb) target remote localhost:1234
Remote debugging using localhost:1234
warning: No executable has been specified and target does not support 
determining executable automatically.  Try using the "file" command.
0xfff0 in ?? ()
(gdb) step
Cannot find bounds of current function
(gdb) list
No symbol table is loaded.  Use the "file" command.
(gdb) continue
Continuing.
[ovmf loads in qemu window]

I can redirect ovmf debug messages into a text file[1].
As far as I understand, there is a way to do source code level debugging
*with* ovmf, to debug efi-apps that are e.g. run via the efi shell[2], with the 
help of SourceLevelDebugPkg[4], but this package cannot be used to source level 
debug the overall boot process, right?

Is it possible to do source level debugging of ovmf?
Is it possible to step through ovmf, one instruction or function call at a time?
How are you ovmf developer debugging it?

If you could point me to the right direction, that would be great.

Kind regards,
Johannes

[1]: I managed to do so via the qemu options -global
isa-debugcon.iobase=0x402 -debugcon file:qemu.ovmf.log" as demonstrated here 
https://www.linux-kvm.org/downloads/lersek/ovmf-whitepaper-c770f8c.txt
[2]:https://github.com/tianocore/tianocore.github.io/wiki/OVMF-FAQ#how-do-i-enable-source-level-debugging-with-ovmf
[3]: 
http://edk2-devel.narkive.com/LRWe2mSQ/using-gdb-on-ovmf-with-symbols
[4]: 
https://github.com/tianocore/tianocore.github.io/wiki/SourceLevelDebugPkg
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel
___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

[edk2] Source code debugging of OVMF

[Johannes Swoboda]

Hello everyone,

I'm doing a research project on efi security. I would like to do source 
code debugging of OVMF. I want to step through the OVMF source code, set 
break points, et cetera, preferably with gdb. I want to debug the 
overall boot process. Is that possible?


I understand I can start qemu with the options -s -S. This gives me a 
virtual machine that awaits connection of a gdb debugger and further 
instructions.


After connecting with gdb, I can instruct the machine to continue 
execution. Unsurprisingly, there is nothing else I can do, because gdb 
lacks the relevant symbols.
I tried to read in the OVMF.fd file, as i would do with a binary that I 
would debug, but gdb can't handle the file.
It seems to be possible to load an efi app with the file command, but 
not this one.


I found one other person trying to achieve the same five years ago. [3] 
suggests that something like this

(gdb) add-symbol-file ../edk2/Build/OvmfX64/DEBUG_GCC5/X64/Shell.debug
The address where ../edk2/Build/OvmfX64/DEBUG_GCC5/X64/Shell.debug has 
been loaded is missing
might be possible. However, it appears to me this is may contain 
information regarding Shell.efi, an efi-app; but I don't want to debug 
an app. I want to debug the overall boot process.


I'm quoting some terminal output to clarify what I'm trying to achieve:
[johannes@johannes-laptop OVMF_efi_hello_world]$ gdb
[...]
(gdb) file OVMF.fd
"/home/johannes/18S/bakk/uefi_virtual/OVMF_efi_hello_world/OVMF.fd": not 
in executable format: File format not recognized

(gdb) target remote localhost:1234
Remote debugging using localhost:1234
warning: No executable has been specified and target does not support
determining executable automatically.  Try using the "file" command.
0xfff0 in ?? ()
(gdb) step
Cannot find bounds of current function
(gdb) list
No symbol table is loaded.  Use the "file" command.
(gdb) continue
Continuing.
[ovmf loads in qemu window]

I can redirect ovmf debug messages into a text file[1].
As far as I understand, there is a way to do source code level debugging 
*with* ovmf, to debug efi-apps that are e.g. run via the efi shell[2], 
with the help of SourceLevelDebugPkg[4], but this package cannot be used 
to source level debug the overall boot process, right?


Is it possible to do source level debugging of ovmf?
Is it possible to step through ovmf, one instruction or function call at 
a time?

How are you ovmf developer debugging it?

If you could point me to the right direction, that would be great.

Kind regards,
Johannes

[1]: I managed to do so via the qemu options -global 
isa-debugcon.iobase=0x402 -debugcon file:qemu.ovmf.log" as demonstrated 
here

https://www.linux-kvm.org/downloads/lersek/ovmf-whitepaper-c770f8c.txt
[2]:https://github.com/tianocore/tianocore.github.io/wiki/OVMF-FAQ#how-do-i-enable-source-level-debugging-with-ovmf
[3]: 
http://edk2-devel.narkive.com/LRWe2mSQ/using-gdb-on-ovmf-with-symbols
[4]: 
https://github.com/tianocore/tianocore.github.io/wiki/SourceLevelDebugPkg

___
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel