That Pi4 UEFI firmware can co-exist with normal RPiOS64 files that are in the first FAT formatted partition, except for config.txt, that determines with its kernel= line what is loaded. You might also want dedicated directories for older or newer start4.elf fixup4.dat files, but what I did (and do) is just keep a whole backup/master copy of the 1st FAT in the rootfs (is in my own backup to NAS and restore from NAS scripts).
Also set partition type to 0xEF00 (ESP) instead of 0x0700 (MS basic data) and GPT of course.
Then note that 'BIOS setting' wil be written directly into the RPI_EFI file, bypassing the normal OS I/O, so you won't see any file timestamp changes, but the file is changed.
The OS you run, Fedora Rawhide or Opensuse Tumbleweed or 'pacman Linux' or Debian Testing (rolling releases) should include almost all drivers you also find in the downstream kernel, but not things that are latest or under NDA w.r.t. VC4/VPU. So no video transcoding, (lib)camera. That is what I remember from 3 years years ago (v1.33 I used at that time). It ran with full X11 desktop (KDE, Xfce), but things you buy/want a Pi for don't work as said, so also no GPIO pins. Also WiFi need firmware, that is Broadcom license, it might not be default in a distro. But the normal basics work fine: CPU, USB2/3, RJ45. But see for yourself what current settings/options are. Especially if you select pure ACPI or pure DeviceTree or Both as API to the Linux OS/kernel might make or break. On RK3588 EDK2-UEFI implementation I had to select DeviceTree, then normal boot of vanilla Opensuse Tumbleweed KDE6 Plasma, for Debian Testing I forgot what worked, but should be the same as the older popular ARM64 SoCs are now included as standard supported (see kernel config files what is enabled/included).
Also don't forget about USB quirks, depending on USB3-SATA chipset. You might need it in GRUB or so. That is Pi4, Pi5 is still no own RJ45 support AFAIK (from WoR win-on-arm discussions).
Also set partition type to 0xEF00 (ESP) instead of 0x0700 (MS basic data) and GPT of course.
Then note that 'BIOS setting' wil be written directly into the RPI_EFI file, bypassing the normal OS I/O, so you won't see any file timestamp changes, but the file is changed.
The OS you run, Fedora Rawhide or Opensuse Tumbleweed or 'pacman Linux' or Debian Testing (rolling releases) should include almost all drivers you also find in the downstream kernel, but not things that are latest or under NDA w.r.t. VC4/VPU. So no video transcoding, (lib)camera. That is what I remember from 3 years years ago (v1.33 I used at that time). It ran with full X11 desktop (KDE, Xfce), but things you buy/want a Pi for don't work as said, so also no GPIO pins. Also WiFi need firmware, that is Broadcom license, it might not be default in a distro. But the normal basics work fine: CPU, USB2/3, RJ45. But see for yourself what current settings/options are. Especially if you select pure ACPI or pure DeviceTree or Both as API to the Linux OS/kernel might make or break. On RK3588 EDK2-UEFI implementation I had to select DeviceTree, then normal boot of vanilla Opensuse Tumbleweed KDE6 Plasma, for Debian Testing I forgot what worked, but should be the same as the older popular ARM64 SoCs are now included as standard supported (see kernel config files what is enabled/included).
Also don't forget about USB quirks, depending on USB3-SATA chipset. You might need it in GRUB or so. That is Pi4, Pi5 is still no own RJ45 support AFAIK (from WoR win-on-arm discussions).
Statistics: Posted by redvli — Tue Jun 24, 2025 7:07 am