# Re: \[PATCH v1 3/3\] partitions/efi: Support gpt\_sector parameter needed by NVIDIA Tegra devices

- From: Christoph Hellwig \<hch@infradead.org\>
- Date: 2021-03-29 06:20:42 
- List: linux-tegra
- Page: https://ratatoskr.run/linux-tegra/2021/03/6401642
- Thread: https://ratatoskr.run/linux-tegra/2021/03/6401622/t.md

```text
On Sun, Mar 28, 2021 at 12:21:00AM +0300, Dmitry Osipenko wrote:
> All NVIDIA Tegra20..124 Android devices use proprietary bootloader
> which supplies the gpt_sector=<sector> kernel cmdline parameter that
> should be used for looking up the EFI partition table on internal EMMC
> storage.  If the kernel cmdline parameter isn't supplied, then the
> partition is expected to be placed around the last but one sector of EMMC.
> 
> Apparently this was done in order to hide the PT from a usual userspace
> tools since EFI entry exists only for compatibility with a Linux kernel,

That's weird, because nothin in Linux relies in EFI partition tables.

> while a custom proprietary partition table is what is really used by
> these Android devices, thus these tools may corrupt the real PT, making
> device unbootable and very difficult to restore.
> 
> Add support for the gpt_sector cmdline parameter which will be used
> for finding EFI entry on internal EMMC storage of NVIDIA Tegra20+ devices.

Didn't we plan to just support the actual partition table format insted?
```