This is wrong. You cannot load a binary into a ROM memory. On most SoCs, thr bootloader is loaded in some RAM (DDR, OCRAM, TCM, or similar).
"Loaded into ROM" means that an external device like a laptop burns the code into non-volatile memory, it doesn't describe what the SoC does every time that it boots.
This article even explains how the A64 loads its initial boot logic into RAM, although there are a couple of extra steps thanks to the "ARM Trusted Firmware" security elements:
>Bootstrapping is complicated by initial memory address space limitations. The SPL is limited to 32 KiB, most likely because the BootROM, or BROM, loads the SPL into SRAM A1, which is a 32 KiB subsection. If the SPL is larger than 32 KiB the BROM will refuse to load it. After the SPL loads U-Boot proper and passes execution to the ATF, U-Boot proper in turn runs the Pine Phone’s u-boot command script.
So...I don't think I understand your complaint. It seems to me that the article does explain how "thr bootloader is loaded in some RAM".
Nonsense. The terms to google for are "boot ROM" or "XIP". Boot Roms execute from rom because all that is available at the time. XIP binaries run from NOR or ROM happily
notably neither spl nor u-boot are xip in this case. spi/mmc are both easily overwritten from within u-boot (or any os loaded later)
u-boot is not a boot rom. it is a bootloader.