[U-Boot] [PATCH v1 1/5] bootcount: store bootcount var in environment

Vaibhav Bedia vaibhav.bedia at gmail.com
Thu Oct 24 13:31:26 CEST 2013


Hi Heiko,

On Tue, Oct 22, 2013 at 6:25 AM, Heiko Schocher <hs at denx.de> wrote:
> If no softreset save registers are found on the hardware
> "bootcount" is stored in the environment. To prevent a
> saveenv on all reboots, the environment variable
> "upgrade_available" is introduced. If "upgrade_available" is
> 0, "bootcount" is always 0 therefore no need to save the
> environment on u-boot boot, if "upgrade_available" is 1 "bootcount"
> is incremented in the environment and environment gets written
> on u-boot start.
> So the Userspace Applikation must set the "upgrade_available"
> and "bootcount" variable to 0 (for example with fw_setenv),
> if a boot was successfully.
>
> Signed-off-by: Heiko Schocher <hs at denx.de>

Just curious... why not save the bootcount in a RTC scratchpad register?
IIRC that's persistent across boot cycles if there's battery backup.


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