State of the UBI fastmap feature

[Richard Weinberger]

On Tue, Sep 2, 2025 at 9:37 AM Alexander Dahl <ada at thorsis.com> wrote:
> > I guess your motivation is reducing the attach time?
>
> Indeed.  Need to reduce boot time here, and UBI is attached twice.
> Once in U-Boot to read the kernel image and then again in Linux.

Some ideas that could significantly improve attach time while being
less invasive than Fastmap:
1. Pass the LEB-PEB mapping from U-Boot to Linux so that scanning
occurs only in U-Boot.
2. Optimize EC/VID header reads:
2.1. If supported by the device, transfer only the actual header size
instead of the entire (sub)page.
2.2. Read headers without ECC (if ECC overhead is measurable). If the
header CRC fails, re-read with ECC.

-- 
Thanks,
//richard