Unable to connect to a BMC Serial Console

Unable to connect to a BMC Serial Console

[Shubhabrata Bose]

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TCS Confidential

Hello Everyone,

I am new to OpenBMC and I need some help about how to access the BMC console which I am not able to, after many tries.
Currently, I have connected my Host Server (i.e., Thinkstation P510 - Intel X86-64 CPU installed with OS: Ubuntu 18.04)
with Intel Server Board S2600GZ (OS :Ubuntu 14) which has a BMC chip using a USB-TTL Serial console cable
("xcluma Usb To Ttl Serial Cable Debugger For Raspberry Pi Beaglebone Cubietruck".)
The minicom is not showing me any prompt & it's paused; nothing is going ahead.
I googled some websites, its suggested to disable the flow control but even that does not help.
Are there any other ways to access it for example web interface etc. or serial console is the only way ?

Thanks in Advance,
Shubh,


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Re: Unable to connect to a BMC Serial Console

[Jeremy Kerr]

Hi Shubh,

> TCS Confidential

Really? :)

> I am new to OpenBMC and I need some help about how to access the BMC
> console which I am not able to, after many tries.

Just to confirm - you're referring to the console for the BMC system
itself, right? As distinct from the host serial.

> Currently, I have connected my Host Server (i.e., Thinkstation P510 –
> Intel X86-64 CPU installed with OS: Ubuntu 18.04)
> with Intel Server Board S2600GZ (OS :Ubuntu 14) which has a BMC chip
> using aUSB-TTL Serial console cable 
> (“xcluma Usb To Ttl Serial Cable Debugger For Raspberry Pi Beaglebone
> Cubietruck”.)
> The minicom is not showing me any prompt & it’s paused; nothing is
> going ahead.

A few things to check:

 - Where have you attached to the TTL signals? Are you sure that's a 
   BMC serial port?
 - What are you expecting to see there? The BMC might only be 
   outputting console data during boot.
 - Are you using the correct baud rate? (since there should be 
   activity on the TX line during boot, you can use this to find the 
   TX line and set your baud rate)

I'm not familiar with the S2600GZ, but I have done a bit of OpenBMC
development using a S2600STB platform, which may be similar. In that
case, slides 25 and 28 of this might help:

http://jk.ozlabs.org/docs/lca2021/lca2021%20-%20Server%20platforms%20-%20Jeremy%20Kerr.pdf

Otherwise, maybe Intel folks here can provide better connection details
for the GZ.

Cheers,


Jeremy

Re: Unable to connect to a BMC Serial Console

[James Mihm]

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Hi Shubh,

Is your goal to replace the Intel BMC firmware stack with an OpenBMC
firmware image?

The Intel S2600GZ server (a.k.a., Grizzly Pass) is an older server with an
Emulex Pilot 2
BMC PSoC with a proprietary firmware stack. Furthermore, the Pilot series
of BMC is not
supported by OpenBMC. Whereas the S2600STP (a.k.a., Sawtooth Pass), that
Jeremy has
referenced, has the AST2500 BMC PSoC and is supported by OpenBMC.

To make things more challenging for hackers, Intel platforms don't have the
BMC serial port
normally accessible. Meaning that the hardware to connect to the BMC serial
port isn't
populated and logging into the BMC via the serial console is disabled.

Regards, James.

On Mon, Oct 10, 2022 at 6:16 PM Jeremy Kerr <jk@codeconstruct.com.au> wrote:

> Hi Shubh,
>
> > TCS Confidential
>
> Really? :)
>
> > I am new to OpenBMC and I need some help about how to access the BMC
> > console which I am not able to, after many tries.
>
> Just to confirm - you're referring to the console for the BMC system
> itself, right? As distinct from the host serial.
>
> > Currently, I have connected my Host Server (i.e., Thinkstation P510 –
> > Intel X86-64 CPU installed with OS: Ubuntu 18.04)
> > with Intel Server Board S2600GZ (OS :Ubuntu 14) which has a BMC chip
> > using aUSB-TTL Serial console cable
> > (“xcluma Usb To Ttl Serial Cable Debugger For Raspberry Pi Beaglebone
> > Cubietruck”.)
> > The minicom is not showing me any prompt & it’s paused; nothing is
> > going ahead.
>
> A few things to check:
>
>  - Where have you attached to the TTL signals? Are you sure that's a
>    BMC serial port?
>  - What are you expecting to see there? The BMC might only be
>    outputting console data during boot.
>  - Are you using the correct baud rate? (since there should be
>    activity on the TX line during boot, you can use this to find the
>    TX line and set your baud rate)
>
> I'm not familiar with the S2600GZ, but I have done a bit of OpenBMC
> development using a S2600STB platform, which may be similar. In that
> case, slides 25 and 28 of this might help:
>
>
> http://jk.ozlabs.org/docs/lca2021/lca2021%20-%20Server%20platforms%20-%20Jeremy%20Kerr.pdf
>
> Otherwise, maybe Intel folks here can provide better connection details
> for the GZ.
>
> Cheers,
>
>
> Jeremy
>
>

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RE: Unable to connect to a BMC Serial Console

[Shubhabrata Bose]

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TCS Confidential


Hi,



Thanks for guiding !!



@Jeremy:



After referring to your slides 25 and 28,  it looks like it’s the Host Serial port (i.e., Serial_B Port next to the IPMB port, in BLACK colored in your slide) that’s the one I am connecting to, so it’s not the BMC Serial port then .

Thanks for pointing out.



@James:



So, for the Intel servers having “AST2500 BMC PSoC” or similar, if BMC serial port is not accessible, then how to connect to the debug console ? Do we need to access via SOL (Serial over Lan), LPC or any other methods.

How do we flash and test our image (that I want to build on QEMU) ??  Also, what are the other options I have for this board S2600GZ, as we have currently only this one where we want to test our codes etc.



Thanks a lot again,

Shubh,


From: James Mihm <james.mihm@gmail.com>
Sent: Tuesday, October 11, 2022 9:32 AM
To: Jeremy Kerr <jk@codeconstruct.com.au>
Cc: Shubhabrata Bose <shubhabrata.bose@tcs.com>; openbmc@lists.ozlabs.org
Subject: Re: Unable to connect to a BMC Serial Console

"External email. Open with Caution"
Hi Shubh,

Is your goal to replace the Intel BMC firmware stack with an OpenBMC firmware image?

The Intel S2600GZ server (a.k.a., Grizzly Pass) is an older server with an Emulex Pilot 2
BMC PSoC with a proprietary firmware stack. Furthermore, the Pilot series of BMC is not
supported by OpenBMC. Whereas the S2600STP (a.k.a., Sawtooth Pass), that Jeremy has
referenced, has the AST2500 BMC PSoC and is supported by OpenBMC.

To make things more challenging for hackers, Intel platforms don't have the BMC serial port
normally accessible. Meaning that the hardware to connect to the BMC serial port isn't
populated and logging into the BMC via the serial console is disabled.

Regards, James.

On Mon, Oct 10, 2022 at 6:16 PM Jeremy Kerr <jk@codeconstruct.com.au<mailto:jk@codeconstruct.com.au>> wrote:
Hi Shubh,

> TCS Confidential

Really? :)

> I am new to OpenBMC and I need some help about how to access the BMC
> console which I am not able to, after many tries.

Just to confirm - you're referring to the console for the BMC system
itself, right? As distinct from the host serial.

> Currently, I have connected my Host Server (i.e., Thinkstation P510 –
> Intel X86-64 CPU installed with OS: Ubuntu 18.04)
> with Intel Server Board S2600GZ (OS :Ubuntu 14) which has a BMC chip
> using aUSB-TTL Serial console cable
> (“xcluma Usb To Ttl Serial Cable Debugger For Raspberry Pi Beaglebone
> Cubietruck”.)
> The minicom is not showing me any prompt & it’s paused; nothing is
> going ahead.

A few things to check:

 - Where have you attached to the TTL signals? Are you sure that's a
   BMC serial port?
 - What are you expecting to see there? The BMC might only be
   outputting console data during boot.
 - Are you using the correct baud rate? (since there should be
   activity on the TX line during boot, you can use this to find the
   TX line and set your baud rate)

I'm not familiar with the S2600GZ, but I have done a bit of OpenBMC
development using a S2600STB platform, which may be similar. In that
case, slides 25 and 28 of this might help:

http://jk.ozlabs.org/docs/lca2021/lca2021%20-%20Server%20platforms%20-%20Jeremy%20Kerr.pdf

Otherwise, maybe Intel folks here can provide better connection details
for the GZ.

Cheers,


Jeremy


TCS Confidential
=====-----=====-----=====
Notice: The information contained in this e-mail
message and/or attachments to it may contain 
confidential or privileged information. If you are 
not the intended recipient, any dissemination, use, 
review, distribution, printing or copying of the 
information contained in this e-mail message 
and/or attachments to it are strictly prohibited. If 
you have received this communication in error, 
please notify us by reply e-mail or telephone and 
immediately and permanently delete the message 
and any attachments. Thank you



[-- Attachment #2: Type: text/html, Size: 9191 bytes --]

Re: Unable to connect to a BMC Serial Console

[Jeremy Kerr]

Hi Shubh,

> After referring to your slides 25 and 28,  it looks like it’s the
> Host Serial port (i.e., Serial_B Port next to the IPMB port, in BLACK
> colored in your slide) that’s the one I am connecting to, so it’s not
> the BMC Serial port then .

OK, yeah - the BMC serial may not be populated with a header. That 3-
pin header (which I have added) is definitely the BMC serial port on my
board.

However, as James has said, the GZ sounds substantially different from
that board, so all bets are off here.

Cheers,


Jeremy

Re: Unable to connect to a BMC Serial Console

[Jiaqing Zhao]

On 2022-10-11 09:06, Jeremy Kerr wrote:
> Hi Shubh,
> 
>> TCS Confidential
> 
> Really? :)
> 
>> I am new to OpenBMC and I need some help about how to access the BMC
>> console which I am not able to, after many tries.
> 
> Just to confirm - you're referring to the console for the BMC system
> itself, right? As distinct from the host serial.
> 
>> Currently, I have connected my Host Server (i.e., Thinkstation P510 –
>> Intel X86-64 CPU installed with OS: Ubuntu 18.04)
>> with Intel Server Board S2600GZ (OS :Ubuntu 14) which has a BMC chip
>> using aUSB-TTL Serial console cable 
>> (“xcluma Usb To Ttl Serial Cable Debugger For Raspberry Pi Beaglebone
>> Cubietruck”.)
>> The minicom is not showing me any prompt & it’s paused; nothing is
>> going ahead.
> 
> A few things to check:
> 
>  - Where have you attached to the TTL signals? Are you sure that's a 
>    BMC serial port?
>  - What are you expecting to see there? The BMC might only be 
>    outputting console data during boot.
>  - Are you using the correct baud rate? (since there should be 
>    activity on the TX line during boot, you can use this to find the 
>    TX line and set your baud rate)
> 
> I'm not familiar with the S2600GZ, but I have done a bit of OpenBMC
> development using a S2600STB platform, which may be similar. In that
> case, slides 25 and 28 of this might help:
> 
> http://jk.ozlabs.org/docs/lca2021/lca2021%20-%20Server%20platforms%20-%20Jeremy%20Kerr.pdf

I used to have a S2600CO4 board which is the same gen (E5v2) as S2600GZ
and tried some reverse engineering before. Bad news is that the BMC on
that generation seems not running linux, or have some encryption.
binwalk over the BMC image gives nothing, as well as 7zip.

Tried the S2600STB BMC image now, binwalk can detect the kernel and
rootfs, and I can use 7zip to extract the rootfs.

And, yeah, most vendors will hide these UART pins for BMC console on
production hardware, you have to find it in your own. Oscilloscope or
multimeter would help. Or if there is some unsoldered pins around BMC
like that on S2600STB, they got a higher chance to be the UART pin.

> 
> Otherwise, maybe Intel folks here can provide better connection details
> for the GZ.
> 
> Cheers,
> 
> 
> Jeremy
>