[U-Boot] [RESENT PATCH v3] rockchip: update emmc/sd index for distro boot order

[Kever Yang]

Hi Philipp,


On 11/30/2018 05:44 AM, Philipp Tomsich wrote:
>
>
>>> With this patch, people can use firmware in SD card if they want;
>>> Without this patch, people never able to use firmware in SD card if eMMC
>>> firmware exist (even if it's broken).
>>
>> Most boards I know have the ability to bypass the internal eMMC.
>
> One last thing: I know a number of projects developing devices using our
> modules that have a SD card slot for data exchange (e.g. config data, log
> files, data acquisition and export) but that don’t want endusers to
> boot the
> device from the SD card (possibly using unauthorized firmware).

Here have few points:
1. people can use SD card as normal storage, I have mentioned about this
in my previous mail;
    We don't affect this feature because SD with firmware need special
format.
2. If vendor don't want end users to using unauthorized firmware, they
need add
    verify boot in U-Boot, or else user can override firmware no matter
is eMMC or SD;
3. If vendor don't want to boot from SD, then they do need update the
source code and delete
    the SD option, because people can still boot from SD only with broke
eMMC boot partition
We are talking about the default boot order of bootable partition, not
about if we can boot
from SD card or if we can use unauthorized firmware.

>
> For factory use, there’s a signal on the mainboard to disable (until
> turned
> back on by software) the on-module eMMC and (if available) SPI to allow
> booting from the external SD card.  For field use, this signal is
> unaccessible
> and can not be asserted…

Thanks for your information, and you are doing very well for your are so
experienced,
and you have consider this case in both software and hardware, but I
know most of the
product vendor does not consider so much like you, and they will depends
on what Rockchip
provide to them.

Like I have said in another mail, I don't want any kind of software or
hardware workaround
after it have been in product type, because not all people want to play
with U-Boot,
and product usually pack with case.

For some product, it still need update or fix with SD/USB for those not
support OTA.

BTW, this feature does not affect products which use Rockchip SDK
directly, because
we are using AOSP image instead of distro image.

I hope those SBC developers can play with different distro based OS
easier without
study bootloader or study Rockchip tools to update eMMC or any kind of
hardware workaround.

Thanks,
- Kever

>
> Hope this provides one example to how different use cases can play out...
>
> Thanks,
> Philipp.