The Amiga supports several ROM/Kickstart “banks”; The original A1000 bank is a 256k chunk starting at $FC0000, this was used right up until the first kickstart 1.4 (alpha), then there was a move to use 512k kickstarts starting earlier at $F80000 (an extra 256k)
The CDTV was an exception as it uses $F00000 for its extended ROM, these are separate physical ROMs (also uses $200000 for the VCD/FMV/mpeg CD32 cart ROM – unsure about this as resources seem to contradict, but the FMV ROM I have definitely loads at $200000)
This was pretty much the same until the CD32 which has a 1Mb kickstart, or, more correctly an original 512k kickstart at $F80000 and an extended kickstart at $E00000.
The A500+/A600/A1200/CD32 are all (electrically) capable of addressing a further 1Mb of space at $A80000 without any hardware modifications.
256k Kickstart 0xFC0000 - 0xFFFFFF 256k chunk
512k Kickstart 0xF80000 - 0xFFFFFF 512k chunk, overlaps the 256k chunk, but starts earlier
1Mb Kickstart 0xF80000 - 0xFFFFFF 512k chunk 0xE00000 - 0xE7FFFF 512k chunk
2Mb Kickstart 0xF80000 - 0xFFFFFF 512k chunk 0xE00000 - 0xE7FFFF 512k chunk 0xA80000 - 0xB7FFFF 1Mb chunk Note, these banks are not contiguous.
ROMs can also be “softloaded” via relocation into different chunks of memory like 0xC00000/0x200000 via KickIt/ReKick/Degrader/RelocKick/skick/mkick etc. if you have some spare memory here’
There are also other areas used for loading additional ROMs, “expansion” ROMs can appear at $E80000 (and maybe $E90000), but they get copied from there (there’s also the ZorroIII address $FF000000, but I’ll ignore 32bit addresses here for now).