[U-Boot] [PATCH v4 2/2] fastboot: handle flash write to GPT partitions

[Steve Rae]

On 15-01-23 09:38 AM, Rob Herring wrote:
> On Fri, Dec 12, 2014 at 5:51 PM, Steve Rae <srae at broadcom.com> wrote:
>> Implement a feature to allow fastboot to write the downloaded image
>> to the space reserved for the Protective MBR and the Primary GUID
>> Partition Table.
>> Additionally, prepare and write the Backup GUID Partition Table.
>
> I've been looking at how to do the same thing here. This is an area
> that suffers from each vendor doing whatever they want. Using vendor
> download/flash tools here is painful. They are all different because
> that is where the value add is. ;) What tool do you use on the host
> side to create the image? I have seen some vendor code to do it, or
> you could use parted plus a disk file and extract the partition table
> from it. I find either method a bit fragile and non-standard IMHO.
>
We use an internal tool -- however, I also note that ALL of the source 
code for our tool is "GPL-2.0+" (expect for one file which is Public Domain)
Is U-Boot (Denx) interested in supporting a "host tool"?

> The 2 options I've come up with are 1) enable USB MS and use whatever
> host side tool you like or 2) use the existing "gpt write" command in
> u-boot and tie that into fastboot "oem format" command. The advantage
> and disadvantage of the latter is that it hides the partitioning
> details in u-boot from the user, but requires changing the u-boot env
> to change partition layout. The partitioning requirements are pretty
> SOC specific it seems.
>
We also have code which creates the GPT tables from a "fastboot oem 
format" command, and (if I understand correctly) we have code that 
implements a "gpt" command line, which creates the GPT tables from env 
variables...
If there is interest here, I could investigate further.

> I'm not saying we can't support both, but having some standardization
> here would be good.
>
> Rob
>
I wasn't trying to promote an exclusive solution with this patch (which 
has been accepted - Thanks!). I was just trying to have an incremental 
change to the existing "fastboot flash" command (to handle the GPT Tables).

Thanks, Steve

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