[Skiboot] trace settings

[Andrew Donnellan]

On 14/09/18 08:45, Raymond Higgs wrote:
> Hi,
> 
> Is it possible to change the trace settings without recompiling the 
> firmware?  I'm interested in messages like this:
> 
>     [   90.072348476,5] OPAL skiboot-v6.0-p1da203b starting...
>     [   90.072352660,7] initial console log level: memory 7, driver 5
>     [   90.072354749,6] CPU: P9 generation processor (max 4 threads/core)
>     [   90.072356576,7] CPU: Boot CPU PIR is 0x0014 PVR is 0x004e1202
> 
> 
> I wouldn't normally post to a development mailing list, but I have 
> looked through a lot of documentation, and cannot find a procedure for this.
> 
> We have an MT 9006-22P machine running RHEL7.5.  It has this firmware:
> 
>     [root at power9 ibm,firmware-versions]# for xxx in `ls`; do echo $xxx:
>     `cat $xxx`; done
>     bmc-firmware-version: 1.23
>     hcode: hw051018a.op920
>     hostboot: f911e5c-pda8239f
>     linux: 4.16.7-openpower2-pbc45895
>     machine-xml: 218a77a
>     name: ibm,firmware-versions
>     occ: 77bb5e6-p623d1cd
>     petitboot: v1.7.1-pf773c0d
>     phandle: a
>     sbe: 8e0105e
>     skiboot: v6.0-p1da203b
>     version: SUPERMICRO-P9DSU-V1.16-20180531-prod
> 
> 
> Please cc me with any replies because I'm not subscribed to the mailing 
> list.

As far as I'm aware, there's no way to do this at present.

The most obvious place to put a setting like this would be NVRAM, but 
that poses an obvious issue - on the machine I'm currently logged into, 
NVRAM itself isn't initialised until 752 lines into the log.

Now we could do that anyway, and just accept that for the first few 
seconds while we don't have NVRAM, we'd rely on the platform defaults. 
That would still let you turn up the log level in time to see PCI, 
OpenCAPI, etc etc messages. (I'm guessing you probably want to turn the 
log level up to see those messages on the console rather than in the 
memory log buffer?)


Andrew

-- 
Andrew Donnellan              OzLabs, ADL Canberra
andrew.donnellan at au1.ibm.com  IBM Australia Limited