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

[Kever Yang]

On 11/28/2018 05:15 PM, Philipp Tomsich wrote:
> Kever,
>
>> On 28.11.2018, at 03:06, Kever Yang <kever.yang at rock-chips.com> wrote:
>>
>> According to the emmc/sdcard index in dts alias, emmc is always 0 and
>> sdcard index is 1, let's update to using correct mmc number for distro
>> boot order in common header.
>>
>> SD card suppost to have higher priority so that people can boot into
>> the firmware in SD card, this is very convenient for developer try with
>> distro img from SUSE, Fedora and etc. Developer only need to 'dd' the
>> Distro image(which id download from OS vendor release) into SD card without
>> any modify and then we can boot it up directly.
> You never addressed the review comment from Klaus (from the review in May):
I do address the review comment and that's why this patch has been V3
but not a RESEND for V1. The source code does not change, while the commit
message has update to make it more clear why this patch is needed.

I'm sorry to Klaus for not sure if I have reply to him directly, but I
do this
because I always not get response after I send out my comments in this
channel,
then I thought send a new patch with necessary update may be more fast to
make patch merged.

>
>> Also prioritising SD card over eMMC does not make any sense to me. At least on
>> RK3399 and RK3368 the default ROM boot order is first eMMC then SD card. So 
>> starting U-Boot from eMMC and then loading the Kernel from SD-card doesn’t sound
>> right for me. 
> This will change default behaviour and may break things for users in the field.
> Before we can move forward, we really need to establish a consensus on this
> and how users will be affected.
>
> While this doesn’t matter much for our boards, as we have logic to rewrite the
> default boot during boot-up anyway, I expect a lot of trouble for mainline users
> with their own boards...
First we have to understand what we want and what we should do, I think the
origin comment "First try to boot from SD (index 0), then eMMC (index 1)" is
what we want, but the index is wrong, so we have to correct it, and my first
commit message is about "index fix".
And I do explain in latest commit message about why we need boot SD first,
but I'm not sure if you have read it.

Rockchip private loaders always make SD as higher priority then eMMC,
because
we may need use SD to update the firmware for eMMC or just a temporary test
only image to check if the PCB is good or not.
I think most of SBC developers prefer to use SD card instead of eMMC,
because
write a SD is easier then update eMMC firmware with vendor tools, and we can
use SD card just like we try a Ubuntu in a Udisk without install it in
hard disk for PC,
just like I write in the commit message.

If we keep eMMC as higher priority, then people have no chance to use
firmware
in SD card if there already have firmware in eMMC.

Then let's check if this "break things for users in the field ", this
patch only affect the
case both eMMC and SD have available firmware(boot.img), right?
I think people only write firmware to SD when they want to boot from it,
or else
people would never do it, the SD will be a normal external storage if
they want to use
the firmware in eMMC. I don't think  there will be "a lot of trouble for
mainline users ".

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).
 

Hi Klaus,
    How do you think?

Thanks,
- Kever
>
>> Signed-off-by: Kever Yang <kever.yang at rock-chips.com>
>> ---
>>
>> Changes in v3:
>> - update the commit message
>> Series-changes: 2
>> - update the commit message
>>
>> include/configs/rockchip-common.h | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/configs/rockchip-common.h b/include/configs/rockchip-common.h
>> index 68e1105a4b..8a72613e52 100644
>> --- a/include/configs/rockchip-common.h
>> +++ b/include/configs/rockchip-common.h
>> @@ -11,11 +11,11 @@
>>
>> #ifndef CONFIG_SPL_BUILD
>>
>> -/* First try to boot from SD (index 0), then eMMC (index 1) */
>> +/* First try to boot from SD (index 1), then eMMC (index 0) */
>> #if CONFIG_IS_ENABLED(CMD_MMC)
>> 	#define BOOT_TARGET_MMC(func) \
>> -		func(MMC, mmc, 0) \
>> -		func(MMC, mmc, 1)
>> +		func(MMC, mmc, 1) \
>> +		func(MMC, mmc, 0)
>> #else
>> 	#define BOOT_TARGET_MMC(func)
>> #endif
>> -- 
>> 2.18.0
>>
>