[U-Boot] [U-boot] mmc write|read howto

[Jagan Teki]

Hi Josh,

On Sat, Apr 27, 2013 at 11:55 AM, Josh Wu <josh.wu at atmel.com> wrote:
> Hi, Jagan
>
>
> On 4/27/2013 4:51 AM, Jagan Teki wrote:
>>
>> Hi All,
>>
>> I need some help regarding mmc write and mmc read commands usage.
>>
>> I am using a 4GB SD/MMC plus and socked eMMC cards, usually I am
>> formatting these cards on my host pc with
>> fat partition and copy the images into card. while in the u-boot level
>> I am reading the images from card and copy it onto mem addr
>> like fatload mmc 0 0x1000 uImage.
>>
>> Can we write the images onto these cards in u-boot level?, using mmc
>> write.
>> same way can we read back using mmc read? if so how to do that.
>
>
> yes, define the CONFIG_FAT_WRITE macro in your board config file.
> re-build your u-boot. then you will find "fatwrite" command.
>
> U-Boot> fatwrite
> fatwrite - write file into a dos filesystem
>
> Usage:
> fatwrite <interface> <dev[:part]> <addr> <filename> <bytes>
>     - write file 'filename' from the address 'addr' in RAM
>       to 'dev' on 'interface'
>
> so you can use:
>  fatwrite mmc 0 0x20000000 file 0x4000

Thanks for your information.

I will try the fatwrite, and this must require to have the card should
formatted as FAT on host, is it?
Any possibility to do the formation on u-boot itself.?

Thanks,
Jagan.

>
> Best Regards,
> Josh Wu
>
>>
>> Request for help.
>>
>> Thanks,
>> Jagan.
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>
>