So why both https://source.denx.de/u-boot/u-boot (mentioned in https://wiki.postmarketos.org/wiki/Fairphone_5_(fairphone-fp5)#U-Boot ) & https://gitlab.postmarketos.org/tauchgang/u-boot , what difference(s) (if the 1st would work…)?
git clone https://gitlab.postmarketos.org/tauchgang/u-boot.git instead?

https://catacombing.org/builder nice, a new Pinephone, Pro & Fairphone 5 OS! I’ve also a Pinephone Pro https://pine64.com/product/pinephone-pro-explorer-edition/ .

What difference(s) between yours & https://github.com/dreemurrs-embedded/Pine64-Arch ? My experience is:
no longer Plasma Mobile https://github.com/dreemurrs-embedded/Pine64-Arch/releases ,
still no replies https://github.com/dreemurrs-embedded/Pine64-Arch/discussions/720 https://github.com/dreemurrs-embedded/Pine64-Arch/discussions/721 …
Otherwise I managed to install ALARM KDE Plasma on my Pinephone Pro https://github.com/jebez1/my_files/blob/main/how-tos/PinePhone_Pro_Arch_Linux_ARM_KDE_Plasma_installer_script.txt .

Precisley I wanna install ALARM Plasma Mobile on Fairphone 5 the Arch way, boot the installer on microSD card or USB drive (?) then execute a installer script, possible on Pinephone Pro https://github.com/dreemurrs-embedded/Pine64-Arch/wiki/Manual-Install-(like-desktop-Arch) , on Fairphone 5, can’t U-Boot or other bootloader (?) boot the microSD card?

Thanks, what difference(s) between the official way & yours?

I flashed your https://catacombing.org/catacomb/u-boot-fairphone-fp5.img.xz : no boot microSD card, but it is my goal, I wanna install Arch Linux ARM on my Fairphone 5.