[U-Boot] spi and block bits

[Jagan Teki]

On 9 February 2015 at 04:57, Michael Walle <michael at walle.cc> wrote:
> Hi there,
>
> I stumbled across a situation where the SPI flash on my board was write
> protected and i could not unlock it in the bootloader. This is especially
> unfortunate because the recovery mechanism relies on the bootloader to be
> able to erase the environment.

Which flash vendor it is? seems like there is a hardware write protected
mechanism in ST MICRON flashes.

Please refer that, may be this looks similar to that W#/Vpp
CONFIG_SYS_SPI_ST_ENABLE_WP_PIN

>
> So any ideas how to fix this? I didn't see any code which unlocks the
> sectors yet.
>
> We could add a lock/unlock function to the spi system, then call unlock in
> the beginning of saveenv() and lock at the end of saveenv(). Eg.
>
>   lockbits = read_status() & LOCK_BITS
>   spi_unlock_all()
>   saveenv()
>   spi_lock(lockbits)
>
> Also this should be exposed to the CLI somehow. "sf lock/unlock"?

thanks!
-- 
Jagan.