[U-Boot] [PATCH] lsxl: Add documentation how to flash an unmodified board

[Bastian Germann]

Hello Michael,

I tried to use the MTD layer but that did not work even though I set the
flash in the Linux device tree read-write. I cannot remember the output
exactly as it is some time ago that I tried (with Debian).

Cheers,
Bastian

Am 07.06.2018 um 09:49 schrieb Michael Walle:
> Am 6. Juni 2018 11:38:56 MESZ schrieb Bastian Germann <bastiangermann at fishpost.de>:
>> Signed-off-by: Bastian Germann <bastian.germann at fishpost.de>
>> ---
>> board/buffalo/lsxl/README | 17 ++++++++++++++++-
>> 1 file changed, 16 insertions(+), 1 deletion(-)
>>
>> diff --git a/board/buffalo/lsxl/README b/board/buffalo/lsxl/README
>> index ef5ed42880..3ede081776 100644
>> --- a/board/buffalo/lsxl/README
>> +++ b/board/buffalo/lsxl/README
>> @@ -111,7 +111,7 @@ rescue
>>   See `Rescue Mode` for more information.
>>
>> You can change the boot source by setting the 'bootsource' variable to
>> the
>> -corresponding value. Please note, that the restore_env script will the
>> the
>> +corresponding value. Please note, that the restore_env script will set
>> the
>> bootsource back to 'legacy'.
> 
> haha had to read twice to see the difference. nice catch. 
> 
>>
>> @@ -137,3 +137,18 @@ you already have a bootloader CLI, you can use the
>> following commands:
>>  bootp ${loadaddr} u-boot.kwb
>>  sf erase 0 +${filelen}
>>  sf write 0 ${fileaddr} ${filesize}
>> +
>> +As netconsole is unavailable in the Buffalo U-Boot version, you can
>> only
>> +flash via bootloader CLI if you modify the board. If you do not want
>> to do
>> +that, you can flash from GNU/Linux with the flashrom utility. You have
>> to
>> +have the flash chip available as a spidev device, which you can get by
>> +enabling Linux configuration option CONFIG_SPI_SPIDEV and adding a
>> spidev
>> +compatible device in the device tree available in the Linux source
>> tree as
>> +arch/arm/boot/dts/kirkwood-lsxl.dtsi
>> +
>> +The flashing is then done with the following commands:
>> +
>> + flashrom -r dump.bin -p linux_spi:dev=/dev/spidev0.0
>> + truncate -s 384K u-boot.kwb
>> + dd conv=notrunc if=u-boot.kwb of=dump.bin
>> + flashrom -w dump.bin -p linux_spi:dev=/dev/spidev0.0
> 
> i guess there is no need for flashrom and raw spi access if you're using the MTD layer (flash_erase /dev/mtd0 0 0 and dd to /dev/mtd0). any advantages of using flash_rom? 
> 
> -michael
>