This script will give you the list of ARM system instructions used in your IDA database. This is useful for locating specific low-level pieces of code (setting up the MMU, caches, fault handlers, etc.).
One hassle of reverse engineering low-level ARM code is that IDA Pro does not
decode the internal registers accessed by co-processor instructions
(MCR/MRC and MSR/MRS on AArch64).
After applying the script, the system registers accessed will be automatically commented in the database, as defined in the official ARM reference manuals.
The script will also try to automatically detect the accessed fields for some registers:
Alt-F7 in IDA Pro, then run the script on your open database.
Should work with ARMv7 and ARMv8 processors.