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
you're talking about different things. u-boot is not a boot rom. the actual bootrom is a maskrom on the a64. the maskrom looks to spi/mmc for spl and u-boot.
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.
UBoot is not generally stored in boot ROM. The boot ROM loads the UBoot binary from somewhere (eg. eMMC, SD, etc) to some RAM, and jumps there.
In case of in place execution, that is not ROM anyway. You may XIP from a NOR memory, but that is still not ROM.
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