Re: [PATCH v3 0/7] Add FIT multi-DTB selection for Qualcomm platforms

[Quentin Schulz <quentin.schulz@cherry.de>]

On 4/20/26 8:11 PM, Tom Rini wrote:
> On Fri, Apr 17, 2026 at 05:39:44PM +0530, Aswin Murugan wrote:
>> This series adds dynamic device tree selection from FIT images for
>> Qualcomm Snapdragon platforms, enabling U-Boot to select the
>> appropriate DTB based on hardware parameters detected from SMEM.
>>
>> Qualcomm fit based DTB format is documented in [1]
>> The fit image contains only DTB, while the kernel will be part of UKI image.
>>
>> The implementation consists of three parts:
>>
>> 1. SMEM cache infrastructure: Provides cached access to commonly
>>     used SMEM data (socinfo, RAM partitions) to avoid redundant
>>     lookups during boot. Includes socinfo header from Linux kernel
>>     for SoC identification.
>>
>> 2. FIT multi-DTB selection: Implements the core selection logic
>>     that reads hardware parameters from SMEM, parses metadata DTB,
>>     matches FIT configurations, and loads the selected DTB with
>>     overlays. Integrates with EFI boot flow by setting fdt_addr.
>>
>> 3. mkimage: add fatfs image type for FAT partition images
>>     Added fatimage.c handler that uses mkfs.vfat and mcopy to create
>>     FAT images from a directory.
> 
> I'm unsure why part 3 here is appropriate for U-Boot. It's wrapping
> existing tooling to create a fat image?
> 

I concur. Aswin, you need to justify with a usecase because I don't see 
a benefit for generating a fat image from mkimage for now. Why do you 
even need a filesystem for just the fitimage? Why not flash the fitimage 
directly on the partition?

Cheers,
Quentin