Re: [RFC PATCH 0/1] Add driver to read secondary bootloader (XBL) log

[Bjorn Andersson]

On Mon, Aug 28, 2023 at 11:44:08AM -0700, Trilok Soni wrote:
> On 8/28/2023 10:19 AM, Arun Kumar Neelakantam wrote:
> > 
> > 
> > On 8/22/2023 5:45 PM, Ninad Naik wrote:
> >> Boot time logs for Qualcomm secondary boot-loader or XBL can help to
> >> identify different set of information regarding firmware configuration,
> >> SoC boot KPIs. A dedicated region is carved out in the memory map in order
> >> to store this log in the memory.
> >>
> >> The objective of this driver is to read the XBL boot log stored in
> >> this memory region post boot-up, and provide an entry in debugfs, which
> >> can be used to read back the logs and print them on to the console.
> >>
> > 
> > I see couple of use cases for this kind of logging like logs from
> > boot, Hypervisor, Trusted Execution environments and also one in
> > upstream for chromeos EC console. Can this be made a generic driver
> > which take log name, log memory buffer address and size to read from
> > debugfs.
> 
> The one downside of generic solution here is that log format may not
> be consistent. Some may have binary format of logs which will need
> further parsing in kernel or userspace. 
> 
> If we need to make such feature generic then it needs to be generic
> across arm64 / arm32 then and not SOC specific. 
> 

More importantly, it should provide a consistent interface towards the
consumer of the data, so that one wouldn't need a custom app to collect
every type of data.

Regards,
Bjorn