[U-Boot] [PATCH] sbc8548: document how to write main flash from alternate flash

[York Sun <yorksun@freescale.com>]

On 03/16/2015 10:57 AM, Paul Gortmaker wrote:
> If you are running on the alternate flash in order to fix a
> corrupted main flash image, it might be good to have the steps
> for that documented as well.
> 
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> ---
>  board/sbc8548/README | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/board/sbc8548/README b/board/sbc8548/README
> index feac5e3e63e5..493ea837ba3b 100644
> --- a/board/sbc8548/README
> +++ b/board/sbc8548/README
> @@ -138,6 +138,18 @@ image in the SODIMM that is built with CONFIG_SYS_ALT_BOOT enabled,
>  	md eff00000 10
>  	protect on all
>  
> +If you are running the alternate 64MB /CS0 settings and want to update
> +the "normal" default 8MB u-boot image, then (built with CONFIG_SYS_ALT_BOOT
> +disabled) the steps will become:
> +
> +	tftp u-boot.bin
> +	md 200000 10
> +	protect off all
> +	erase effa0000 efffffff
> +	cp.b 200000 effa0000 60000
> +	md effa0000 10
> +	protect on all
> +
>  Finally, if you are running the alternate 64MB /CS0 settings and want
>  to update the in-use u-boot image, then (again with CONFIG_SYS_ALT_BOOT
>  enabled) the steps will become:
> 

It's good to have it documented. I don't think the "protect" command is needed
in this case (and some other cases in this README). You are not flashing current
booting image, the protection is just a software flag which only marks "RO" for
current image. You can confirm by running "flinfo" to show all sectors. The
protected sectors have "RO".

York