[U-Boot] Should I create a new UCLASS for Bootstate or Add new Ops to UCLASS_BOOTCOUNT ??

[Simon Glass]

Hi Joel,

On Sat, 7 Sep 2019 at 18:34, Joel Peshkin <joel.peshkin at broadcom.com> wrote:
>
>
> Hi Simon,
>
>    I need to create and upstream driver for a set of functions that manage volatile information that persist across reboots.   These are simple registers that survive reboot but get cleared on power-cycle.   The key operations we need to implement are ...
>
> boot_state_set_alternate_image_once()
>     Called before rebooting  (from uboot proper or from Linux)... sets flags to cause the next reboot to select an alternate image
>
> boot_state_getandclear_alternate_image()
>     Called during boot (during SPL or TPL if using dual-uboot images as we do).  Gets the status of the alternate_image flag and clears it.
>
> In our implementation, we have registers that always clear on power-cycle, but survive the soft reboot.  Other implementations, where there is no such register, would still only use the alternate image once as long as the boot attempt reaches the getandclear_alternate_image() function, so drivers similar to those available in bootcount could easily handle the same function.
>
>    Would you prefer that I create a new UCLASS or is it OK to extend the UCLASS_BOOTCOUNT operations and upstream the new operations, supported on a subset of the drivers that implement UCLASS_BOOTCOUNT ??

I think that adding new operations makes sense for now.

I've added a few other people for thoughts.

Regards,
Simon