On 09/04/2014 05:45 PM, Robert Nelson wrote:
> On Thu, Sep 4, 2014 at 4:22 PM, Robert Nelson <robertcnel...@gmail.com> wrote:
>>>>
>>>> dd if=MLO of=/dev/sdX count=1 seek=1 conv=notrunc bs=128k
>>>> dd if=u-boot.img of=/dev/sdX count=2 seek=1 conv=notrunc bs=384k
>>>>
>>>> So far i've only got it to reliabley work on omap4+ bootroms (which
>>>> include the am335x).. so beagle/beagle-xm, not yet...
>>>
>>> You need to be really good about wiping out the FAT partition before you
>>> do this or you'll run into problems of the ROM finding things that
>>> aren't there anymore. Doing a dd if=/dev/zero of=/dev/sdXp1 before
>>> re-doing the partition table is a good idea.
>>
>> Yeah, we do both a zero out and read back flush for good measures...
>>
>> dd if=/dev/zero of=${media} bs=1M count=100 || drive_error_ro
>> sync
>> dd if=${media} of=/dev/null bs=1M count=100
>> sync
>>
>> mkfs.ext4 in debian jessie started getting picky, so we had to zero
>> out past the end of the first partition, otherwise it still saw the
>> old partition and warned us. (therefor we couldn't no longer script
>> that..)
>
> Tom, by the way.. When we 'update' a dd'ed bootloader, how many
> sectors should be blank with /dev/zero to be on the safe side. (this
> is for situations where i don't wan to blow out mbr, but just want to
> update the mlo/u-boot.img)
Just updating an existing one? This isn't NAND/NOR so you're fine just
overwriting things in place. You can even store a back-up MLO at 0x200
offset (ROM checks 0x0, 0x100 0x200 and 0x300 and we cut the last
location off the list and put U-Boot there).
--
Tom
--
For more options, visit http://beagleboard.org/discuss
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