[PATCH 1/2] doc: Detailed example for netconsole setup

[Fiona Klute]

Am 17.05.24 um 09:32 schrieb Heinrich Schuchardt:
> On 5/14/24 22:20, Fiona Klute wrote:
>> This adds details that I would have liked to have readily available,
>> in particular how to activate the network interface before enabling
>> netconsole, and how to integrate netconsole so you can use the U-Boot
>> prompt.
>>
>> Signed-off-by: Fiona Klute <fiona.klute at gmx.de>
>> ---
>>   doc/usage/netconsole.rst | 33 ++++++++++++++++++++++++++++++++-
>>   1 file changed, 32 insertions(+), 1 deletion(-)
>>
>> diff --git a/doc/usage/netconsole.rst b/doc/usage/netconsole.rst
>> index 2aa3b9ccc5..0c983e6970 100644
>> --- a/doc/usage/netconsole.rst
>> +++ b/doc/usage/netconsole.rst
>> @@ -18,7 +18,9 @@ broadcast address and port 6666 are used. If it is
>> set to an IP
>>   address of 0 (or 0.0.0.0) then no messages are sent to the network.
>>   The source / listening port can be configured separately by setting
>>   the 'ncinport' environment variable and the destination port can be
>> -configured by setting the 'ncoutport' environment variable.
>> +configured by setting the 'ncoutport' environment variable. Note that
>> +you need to set up the network interface (e.g. using DHCP) before it
>> +can be used for network console.
>>
>>   For example, if your server IP is 192.168.1.1, you could use::
>>
>> @@ -107,3 +109,32 @@ as follows:
>>
>>   Note that unlike the U-Boot implementation the Linux netconsole is
>>   unidirectional, i. e. you have console output only in Linux.
>> +
>> +Setup via environment
>> +---------------------
>> +
>> +If persistent environment is enabled in your U-Boot configuration, you
>> +can configure the network console using the environment. For example::
>
> Thanks for adding this information.
>
> Prefixing lines with => makes copying harder.
> If you see value in showing the prompt, please, use
>
> .. prompt:: bash =>

Good point, I've sent a v3 series to address this.

Best regards,
Fiona

>> +
>> +    => env set autoload no
>> +    => env set hostname "u-boot"
>> +    => env set bootdelay 5
>> +    => env set nc 'dhcp; env set stdout nc; env set stdin nc'
>> +    => env set ncip 192.168.1.1
>> +    => env set preboot "${preboot}; run nc;"
>> +    => env save
>> +    => reset
>> +
>> +``autoload no`` tells the ``dhcp`` command to configure the network
>> +interface without trying to load an image. ``hostname "u-boot"`` sets
>> +the hostname to be sent in DHCP requests, so they are easy to
>> +recognize in the DHCP server log. The command in ``nc`` calls ``dhcp``
>> +to make sure the network interface is set up before enabling
>> +netconsole.
>> +
>> +Adding ``nc`` to ``preboot`` tells U-Boot to activate netconsole
>> +before trying to find any boot options, so you can interact with it if
>> +desired.
>> +
>> +``env save`` stores the settings persistently, and ``reset`` then
>> +triggers a fresh start that will use the changed settings.
>> --
>> 2.43.0
>>
>