[PATCH v2 4/5] watchdog: rti_wdt: Add support for loading firmware

[Jan Kiszka]

On 07.06.21 13:40, Tom Rini wrote:
> On Mon, Jun 07, 2021 at 03:33:52PM +0530, Lokesh Vutla wrote:
>> +Tom,
>>
>> Hi Tom,
>>
>> On 02/06/21 3:07 pm, Jan Kiszka wrote:
>>> From: Jan Kiszka <jan.kiszka at siemens.com>
>>>
>>> To avoid the need of extra boot scripting on AM65x for loading a
>>> watchdog firmware, add the required rproc init and loading logic for the
>>> first R5F core to the watchdog start handler. In case the R5F cluster is
>>> in lock-step mode, also initialize the second core. The firmware itself
>>> is embedded into U-Boot binary to ease access to it and ensure it is
>>> properly hashed in case of secure boot.
>>>
>>> One possible firmware source is https://github.com/siemens/k3-rti-wdt.
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
>>> ---
>>>  drivers/watchdog/Kconfig      | 20 ++++++++++++
>>>  drivers/watchdog/Makefile     |  5 +++
>>>  drivers/watchdog/rti_wdt.c    | 58 ++++++++++++++++++++++++++++++++++-
>>>  drivers/watchdog/rti_wdt_fw.S | 20 ++++++++++++
>>>  4 files changed, 102 insertions(+), 1 deletion(-)
>>>  create mode 100644 drivers/watchdog/rti_wdt_fw.S
>>>
>>> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
>>> index f0ff2612a6..1a1fddfe9f 100644
>>> --- a/drivers/watchdog/Kconfig
>>> +++ b/drivers/watchdog/Kconfig
>>> @@ -209,6 +209,26 @@ config WDT_K3_RTI
>>>  	  Say Y here if you want to include support for the K3 watchdog
>>>  	  timer (RTI module) available in the K3 generation of processors.
>>>  
>>> +if WDT_K3_RTI
>>> +
>>> +config WDT_K3_RTI_LOAD_FW
>>> +	bool "Load watchdog firmware"
>>> +	depends on REMOTEPROC
>>> +	help
>>> +	  Automatically load the specified firmware image into the MCU R5F
>>> +	  core 0. On the AM65x, this firmware is supposed to handle the expiry
>>> +	  of the watchdog timer, typically by resetting the system.
>>> +
>>> +config WDT_K3_RTI_FW_FILE
>>> +	string "Watchdog firmware image file"
>>> +	default "k3-rti-wdt.fw"
>>> +	depends on WDT_K3_RTI_LOAD_FW
>>> +	help
>>> +	  Firmware image to be embedded into U-Boot and loaded on watchdog
>>> +	  start.
>>
>> I need your input on this proach. Is it okay to include the linker file unders
>> drivers?
> 
> Maybe?  I suppose the first thing that springs to mind is why aren't we
> using binman and including this blob (which I happily see is GPLv2)
> similar to how we do things with x86 for one example.
> 

See https://www.mail-archive.com/u-boot@lists.denx.de/msg377894.html

Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux