Re: [PATCH v1] partitions/efi: Add 'gpt_sector' kernel cmdline parameter

[Dmitry Osipenko]

19.02.2020 19:27, Christoph Hellwig ÐÐÑÐÑ:
> On Wed, Feb 19, 2020 at 07:23:39PM +0300, Dmitry Osipenko wrote:
>> The gpt_sector=<sector> causes the GPT partition search to look at the
>> specified sector for a valid GPT header if the GPT is not found at the
>> beginning or the end of block device.
>>
>> In particular this is needed for NVIDIA Tegra consumer-grade Android
>> devices in order to make them usable with the upstream kernel because
>> these devices use a proprietary / closed-source partition table format
>> for the EMMC and it's impossible to change the partition's format. Luckily
>> there is a GPT table in addition to the proprietary table, which is placed
>> in uncommon location of the EMMC storage and bootloader passes the
>> location to kernel using "gpt gpt_sector=<sector>" cmdline parameters.
>>
>> This patch is based on the original work done by Colin Cross for the
>> downstream Android kernel.
> 
> I don't think a magic command line is the way to go.  The best would be
> to reverse-engineer the proprietary partition table format.  If that is
> too hard we can at least key off the odd GPT location based of it's
> magic number.

I'll try to take a look at RE, pretty sure somebody tried to do that before.