Bug#1112448: partman-partitioning: GPT may overwrite U-Boot on armhf and arm64 platforms

[Pascal Hambourg <pascal@plouf.fr.eu.org>]

On 29/08/2025 at 15:14, Pascal Hambourg wrote:
> The default partition table type for arm64/* and armhf/efi platforms is 
> GPT. However, GPT standard layout overlaps with the boot location of
> some SoC families such as Allwinner sunxi and NXP/Freescale i.MX.
(...)
> The default partition table type is used by both manual creation of a
> new partition table in normal install and guided partitioning using an
> entire disk.
(...)
> Proposed solutions:
> - Force MSDOS default type on SD/eMMC if the platform boot location 
> overlaps with the GPT area.
> - Force MSDOS default type on SD/eMMC if the platform boot location 
> overlaps with the GPT area and a boot loader is detected.
> - Force MSDOS default type on SD/eMMC if the platform boot location 
> overlaps with the GPT area and a boot loader is detected or the platform 
> does not support an alternate boot location.

- Additionally for automatic partitioning, if the current partition 
table is GPT, then just remove all partitions instead of creating a new 
partition table, assuming that the existing partition table does not 
overlap with U-Boot.