[U-Boot] [PATCH 3/4] mx6ul_14x14_evk: Remove CONFIG_SPL_FAT_SUPPORT

[Peng Fan <b51431@freescale.com>]

On Wed, Sep 09, 2015 at 03:36:38PM +0200, Stefano Babic wrote:
>Hi Fabio,
>
>On 09/09/2015 14:26, Fabio Estevam wrote:
>> Hi Peng and Stefano,
>> 
>> On Wed, Sep 9, 2015 at 4:37 AM, Stefano Babic <sbabic@denx.de> wrote:
>> 
>>>>> #define CONFIG_SPL_LIBCOMMON_SUPPORT
>>>>> #define CONFIG_SPL_MMC_SUPPORT
>>>>> -#define CONFIG_SPL_FAT_SUPPORT
>>>>
>>>> Can we keep this? Without this, we need to burn u-boot.img into sdcard, but
>>>> i prefer to load u-boot.img from the fat partition.
>>>
>>> Well, how U-Boot is stored on the SD-Card is a decision that you take
>>> based on the balance safety against comfortably.
>>> Both are ok on my side. If we put u-boot.img in raw SD at a fixed
>>> address, it is very uncommon that a user destroy accessing it. On the
>>> other side, putting it into a FAT partition makes easier to update for
>>> everybody - just copying it into a disk.
>>> The issue reported by Fabio is like a corrupted SD-Card - the SD-Card
>>> does not contain the correct bootloader and it is ok if it does not boot
>>> or hangs. Both ways have advantages and disadvantages.
>> 
>> I am trying to get this more standard across Freescale boards.

Fabio and Stefano,

I agree that we have a common way for Freescale boards. But why
not choose SPL_FAT? In future we may add QSPI or SPI SPL boot, then we
also need to burn u-boot.img as a raw image to sd card? or burn it
to spi/qspi chips? I think the easy way is FAT load from mmc.

Also see the following,
#define CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR 138 /* offset 69KB */           
#define CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS      800 /* 400 KB */                
#define CONFIG_SYS_MMCSD_FS_BOOT_PARTITION      1                               
#define CONFIG_SYS_MONITOR_LEN  (CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS/2*1024)

It u-boot.img is bigger than 400KB, we also need to change the macro definitions,
why not choose FAT and we do not need to care about that u-boot.img may be bigger
than 400KB, right? And 400KB is a fixed size, whether u-boot.img is saying 100KB or 200KB.

In future, if our mfgtool need to support SPL, each time we need to modify related macro in uboot,
we need to uppdate mfgtool. We suffer for changing both.

Regards,
Peng.
>> 
>> Like it was pointed out here:
>> http://lists.denx.de/pipermail/u-boot/2015-August/222061.html
>> 
>> I think it can be confusing for the end user if each FSL board has a
>> different way for booting u-boot.img, so that's why I chose the common
>> approach here.
>
>Absolutely - the user will be confused. I am fine with any decision you
>take on that sense. IMHO in Freescale's boards (I mean, since MX51 and
>later) has always written u-boot in raw mode. My vote goes for removing
>the flag, then.



>
>Regards,
>Stefano Babic
>
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