[U-Boot] [PATCH RFC] add CONFIG_BOOTCOUNT_LIMIT for MCF5445x

[Wolfgang Denk]

Dear Wolfgang Wegner,

In message <1272026324-18566-1-git-send-email-w.wegner at astro-kom.de> you wrote:
> This patch adds bootcount for Freescale MCF5445x. Two registers of
> eDMA transfer control descriptors (TCD[1]) are used because these
> are unused by linux kernel (freescale LTIB linux-2.6.25) and were
> tested to keep their contents across resets.
...
> +#ifdef CONFIG_BOOTCOUNT_LIMIT
> +/*
> + * We use transfer descriptor registers as a persistent storage
> + * across resets. This was tested on a MCF54455.
> + * Neither U-Boot nor the stock LTIB kernel seem to use
> + * TCD[1], so it should be safe at least until application
> + * start.

This is not sufficent, then. The bootcounter requires to be reset from
User Space, i. e. _after_ the application has been succesfully
started. If application start messes with the value, this fails to
work.

Best regards,

Wolfgang Denk

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