[PATCH 02/11] distro_bootcmd: Add SF support

[Alexander Graf]

On 20.01.20 18:22, Tom Rini wrote:
> +A few people that may have insight to my question
>
> On Sat, Dec 21, 2019 at 01:24:31PM +0530, Jagan Teki wrote:
>
>> Add distro boot command support for SPI flash.
>>
>> This distro boot will read the boot script at specific
>> location at the flash and start sourcing the same.
>>
>> The common macro like BOOTENV_SHARED_FLASH would help
>> to extend the support for nand flash in future.
>>
>> Cc: Tom Rini <trini at konsulko.com>
>> Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> What distro is this for?  My concern here is that hundreds of boards
> (literally) grow by a few hundred bytes to add in this bit of additional
> default logic.  That's not a big problem if distributions are now going
> to be using SPI flash as where they're programming in their bootscript.
> But, who is doing that?  Thanks!


I am not aware of any "distro" that puts a U-Boot script at offset 0 of 
the SPI Flash.

Traditionally, SPI Flash boot setups were always very hand crafted - 
exactly the opposite of what distro boot is for. That said, I think 
supporting SPI Flash boot for rk3399 is great! Albeit I would personally 
only store U-Boot and the environment on SPI, not the target OS.

Jagan, is putting a U-Boot script on the SPI Flash something you thought 
of or something that the rk3399 reference board already does? If it's 
the latter, maybe you could add it as a board custom boot function?


Alex