[U-Boot] hardware versions to Kernel

[Andy Rea]

I have an ARM CPU on a board that has 3 optional sub boards plugged into it,
all of which have 3 hardware rev bits connected to the CPU

 

Rather than getting the CPU to do mmap type stuff or sys/class/gpio stuff to
read those versions in the kernel, is there a way for u-boot to push that
information ( even it's a U32 or a string ) into the kernel somewhere that
can be parsed?  I tried some code in the board startup to create env vars to
append into the bootargs but they aren't evaluated each boot properly (
boards are optional and revs can change )  so cat /proc/cmdlne stayed the
same value all the time

 

Is there a better way to do this?

 

thanks

 

Andy

 

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