Re: RFC : mmc : boot partition is set as a read-write.

NamJae Jeon
2011-09-19T03:56:19Z

2011/9/19 Chris Ball <cjb@laptop.org>:
> Hi,
>
> On Sun, Sep 18 2011, NamJae Jeon wrote:
>> mmc : boot partition is set as a read-write.
>>
>> There is a case that user directly update boot partition through mmcblk0boot0,1.
>> However, the current boot partition is set as a read-only.
>> I suggest that boot partition is set as a read-write if there is no
>> reason that it should be read-only.
>
> There is a reason.
>
> Documentation/mmc/mmc-dev-parts.txt:
>
> MMC Boot Partitions
> ===================
>
> Read and write access is provided to the two MMC boot partitions. Due to
> the sensitive nature of the boot partition contents, which often store
> a bootloader or bootloader configuration tables crucial to booting the
> platform, write access is disabled by default to reduce the chance of
> accidental bricking.
>
> To enable write access to /dev/mmcblkXbootY, disable the forced read-only
> access with:
>
> echo 0 > /sys/block/mmcblkXbootY/force_ro
>
> ==
> - Chris.
> --
> Chris Ball   <cjb@laptop.org>   <http://printf.net/>
> One Laptop Per Child
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Hi. Chris.

There is the way you are.

Thanks a lot.