BBC BASIC(SDL) Assembler on AArch64?

Over on Stardot there was someone that wanted to see an AArch64 assembler in Richard T. Russell’s excellent “BBC BASIC for SDL” (https://stardot.org.uk/forums/viewtopic.php?f=54&t=20530)

I did a little bit of digging, and came across the Arm manual for ArmV8 (which is essentially the 64 bit extension to the Arm architecture/instruction set. Sadly I am out of my depth in understanding technical documentation, and things like instruction set encodings.

I am asking here, if there is anyone here that would be confident in assisting the BBC BASIC for SDL developer in adding a AArch64/ Armv8 assembler for BBC BASIC for SDL? (Ideally it needs someone reasonably familiar with how that architecture works, and the syntax of assembler listings likely to be written for routines hosted in BBC BASIC for SDL. Ideally the syntax should be as fare as possible close to that already used in BBC BASIC for SDL.)

The existing “BBC Basic for SDL” repository is here : https://github.com/rtrussell/BBCSDL
with it’s existing Arm4(?) based assembler being the file https://github.com/rtrussell/BBCSDL/blob/master/src/bbasmb_arm_32.c

Of course if someone wanted to extend the ARM BASIC assembler to cope with AArch64 as well…

I am asking here, if there is anyone here that would be confident in assisting the BBC BASIC for SDL developer in adding a AArch64/ Armv8 assembler for BBC BASIC for SDL?

When Richard was first developing his BASIC for ARM he asked me about the assembler and I had a go. It was not long before I realised it was way beyond me. ;-(

I have since written some code that generates assembler in a small way, but that does not change my mind that it is a huge job. Perhaps ask about the VFP extensions for ARM BASIC. ;-)