Re: [U-Boot] a few questions about saving bootcount in the environment

Dear Robert,

In message alpine.LFD.2.20.1607260734020.10018@localhost.localdomain you wrote:

ok, i am now *totally* confused, so let's start at the beginning. it's my understanding that selecting CONFIG_BOOTCOUNT_LIMIT means you

right.

want to use the boot counter, it does *not* select what method you want to use to store the boot counter, correct? but here's the confusing part.

Which exact part is confusing?

#ifdef CONFIG_BOOTCOUNT_LIMIT
      bootcount = bootcount_load();
      bootcount++;
      bootcount_store(bootcount);
      setenv_ulong("bootcount", bootcount);      <----- ?????
      bootlimit = getenv_ulong("bootlimit", 10, 0);
#endif /* CONFIG_BOOTCOUNT_LIMIT */

This is only the equivalent of a "setenv", so you have a variable in the environment which you can use in scripts or compare against "bootlimit".

There is NO automatic "saveenv" here...

and that's what confuses the heck out of me. i thought that, depending on the technique i wanted to use to store the boot counter (RAM, I2C,

The key word here is "store", i. e. store in such a way that the value survives a warm boot / reset. The copy in RAM which is created above does NOT survive.

whatever), it would use *exclusively* that technique, and while i can see the use of the routines bootcount_load() and bootcount_store(), which are redefined based on the technique you select:

These methods access the persistent copy of the variable. The setenv_ulong() just creates a transient work copy.

it appears that, no matter what, the environment *is* updated every single time because of this line in the bootdelay_process() routine:

setenv_ulong("bootcount", bootcount);

Yes, it is. But it is NOT saved to persistent storage.

Best regards,

Wolfgang Denk