Having attempted to install Linux on an ARM device I think the real answer boils down to how ARM works. You could have UEFI or a BIOS but more likely the CPU will scan for data at specific offsets toward the beginning of the disk for a bootable kernel.
the SoC will likely look in EMMC, then SD, then SPI for devices, then execute at a specific address when it finds something like how BIOS looks for the 512 bytes at the start of a GPT volume.
My pinebook has towboot on the SPI rom. It boots towboot and towboot knows how to load a kernel over NVME. Then its basically at the kernel already.
Having attempted to install Linux on an ARM device I think the real answer boils down to how ARM works. You could have UEFI or a BIOS but more likely the CPU will scan for data at specific offsets toward the beginning of the disk for a bootable kernel.
Most ARM devices I’ve fucked about with have uboot or towboot
Isn’t that just the boot loader you’re still writing to some specific part of the disk for the CPU to find?
the SoC will likely look in EMMC, then SD, then SPI for devices, then execute at a specific address when it finds something like how BIOS looks for the 512 bytes at the start of a GPT volume.
My pinebook has towboot on the SPI rom. It boots towboot and towboot knows how to load a kernel over NVME. Then its basically at the kernel already.