Re: [PATCH v2 2/2] i.MX: HAB: update text for HABV4_CSF_UNLOCK_UID

[Jonas Rebmann <jre@pengutronix.de>]

Hi,

On 2026-04-22 09:43, Sascha Hauer wrote:
> Hi Fabian,
> 
> On Wed, Apr 15, 2026 at 01:10:22PM +0200, Fabian Pflug wrote:
>> With the establishment of global.soc_uid_hex, there is no need to look
>> for the serial number and reverse it.
>>
>> Also some SoC's will have 128-bit UID's, so the hint to 64-bit is not
>> correct and should be removed.
>>
>> Signed-off-by: Fabian Pflug <f.pflug@pengutronix.de>
>> ---
>>   arch/arm/mach-imx/Kconfig | 11 +++--------
>>   1 file changed, 3 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
>> index 2e4d1ac80a..cb77d0d5b6 100644
>> --- a/arch/arm/mach-imx/Kconfig
>> +++ b/arch/arm/mach-imx/Kconfig
>> @@ -918,17 +918,12 @@ config HABV4_CSF_UNLOCK_UID
>>   	depends on HABV4 && HABV4_CSF_UNLOCK_FIELD_RETURN
>>   	string "CSF Unlock UID"
>>   	help
>> -	  Device specific 64-bit UID required to unlock the field-return
>> +	  Device specific UID required to unlock the field-return
>>   	  feature. This value must match the per device UNIQUE_ID fuses.
>>   
>>   	  The below example shows the expected format. The UNIQUE_ID is
>> -	  printed during boot by barebox:
>> -	    i.MX___ unique ID: 7766554433221100
>> -	  or it can be queried by Linux via:
>> -	    - cat /sys/devices/soc0/serial_number
>> -	      7766554433221100
> 
> I don't think we should remove this. For some people it might be more
> convenient to read the SoC UID from Linux or to parse it from the
> barebox console log.

If instructions of reversing /sys/devices/soc0/serial_number are kept, I
suggest to indicate that it's Linux' that prints them in reverse on
i.MX. `drivers/soc/imx/soc-imx8m.c` and `soc-imx.c` flat out present the
SoC UID in reverse order, at least consistently across i.MX SoCs.

There is an unambiguous order of the byteorder in the registers; and for
reasons beyond my comprehension (inattention?) it was chosen for the
kernel to print them uid[16],uid[15],uid[14],... Although the vendor
seems to do the obvious and expect uid[0],uid[1],uid[2],...

Regards,
Jonas

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