ARM Assembly

Install (Only Once):

sudo apt install binutils-arm-none-eabi 
sudo apt install qemu-system-arm    

Assembler & Runtime Assemble:

arm-none-eabi-as add.s

none refers to baremetal, i.e. no operating system

Run:

qemu-system-arm -M sx1 -kernel a.out -nographic -serial pty

View all Registers:

info registers	

Examine 4 RAM Address from:

x /4i  0x10010034

Program Usually Starts on 0x10010034

To quit QEMU:

(qemu) q

type q.

References

https://en.wikipedia.org/wiki/ARM_architecture#Registers
https://developer.arm.com/docs/100166_0001/latest/programmers-model/processor-core-register-summary
https://developer.arm.com/docs/dui0801/latest/overview-of-aarch32-state/registers-in-aarch32-state

For detailed debugging see GDB:
https://github.com/EN10/arm-as/blob/master/GDB.md

Notes on Source

@ is an arm single line comment like ' in VB.NET
/* */ is used for multiline comments like in C

Source must end with newline otherwise:
Assembler end of file Warning

Infinite loop needed at the end otherwise:
qemu: fatal: Trying to execute code outside RAM

-o flag can be used to specify output name

arm-none-eabi-as -o ADD.o ADD.s

AQA ARM:
http://filestore.aqa.org.uk/resources/computing/AQA-75162-75172-ALI.PDF

Instructions Examples:

• ADD
• SUB
• AND
• LSL
• CMP
• IfElse