Thank you very much good information
I will try "git bisect"and I wiil report.
progress:
I was able to get the commit for this RK3588 boot failure with "git bisect" maybe , many thanks.
Merge tag 'v2025.07-rc5' into next · u-boot/u-boot@184e7d0
Prepare v2025.07-rc5
With this merge, tighten up the LTO_FLAGS removal we added to not
trigger on ARMv7 (which is Thumb-2 and should be fine).
github.com
This commit was merge commit, I will investigate more.