Limine 9.0 is out today as the newest major release for this open-source modern multi-protocol bootloader and boot manager. Limine also boasts its own Limine Boot Protocol in addition to the native Linux support and chainloading/multiboot capabilities.
One change that will surprise some readers is Limine 9.0 doing away with EXT4 file-system support as well as older EXT2 and EXT3 support. The change-log notes of dropping the EXT4 file-system support:
Ahh, so the boot partition on linux doesn’t necessarily need to be ext4, so it doesn’t matter if it’s not supported
Between you and another reply I understand now, thank you!
UEFI standard requires support for FAT and then can implement other file systems for the EFI System Partition.
But no vendor actually implements any with the exception of those forced to include APFS by Apple. So FAT is the de facto standard for all ESPs for years.
Actually some vendors implements NTFS driver in their UEFI as well.