On 2/16/26 10:21 PM, Daniel Golle wrote:
Hi,
This RFC series adds a new boot method for OpenWrt's "uImage.FIT with
embedded rootfs" firmware model, along with the underlying infrastructure
to load FIT images on-demand directly from storage devices without copying
them entirely to RAM first.
I would like to discuss the design with U-Boot maintainers and fellow
OpenWrt developers before submitting a formal patch series.
[...]
4. On-demand loading: None of the existing methods support loading FIT
subimages directly from storage. OpenWrt's FIT images typically
contain a 5-20 MB squashfs that does NOT need to be copied to RAM —
the kernel maps it directly from flash. The bootloader only needs
to load the kernel and DTB (~5-10 MB), not the entire 20-50 MB
container. This requires a new loading abstraction.
Isn't this partial loading exactly what SPL does when the fitImage is
generated with external data (mkimage -E) ? SPL loads and traverses the
tree, and then loads the remaining chunks (files) only when needed if I
recall it right ?
Can that SPL code be reused instead ?
