How can ARMv8 memory mapped registers ( ex : EDITCTRL ) be programmed in assembly ?
As they are memory-mapped, with LDR and STR instructions. Did you mean how do you know what the address of the registers is? If so, I believe that is SoC specific, so you'd need to look it up in the SoC's documentations.
No this is not an SoC location , it is a register defined as part of ARMv8 architecture and resides within the core .
The ARMv8 manual gives it's offset as 0xF00 , but I don't know what it's address would be or if I can access it
using LDR / STR or need a special intruction like MCR / MRC / MSR / MRS etc ...
That's not quite correct.
The architecture defines a number of memory mapped registers. It also defines their offsets from a base address. What is SoC dependent is what the base address is.
If you specifically want to access the memory mapped registers from software you will use regular memory access instructions (LDR/STR). But you will need to know where in the SoC's memory map those registers are.
View all questions in Cortex-A / A-Profile forum