Instruction Set¶

Essential varm instructions for learning assembly programming.

Data Movement¶

mov rd, src: Copy value

mov r0, #42     ; Immediate
mov r1, r0      ; Register copy

mvn rd, src: Bitwise NOT

Arithmetic¶

add rd, rn, rm: Addition

add r2, r0, r1  ; r2 = r0 + r1

sub rd, rn, rm: Subtraction mul rd, rn, rm: Multiplication rsb rd, rn, imm: Reverse subtract (imm - rn) adc: Add with carry sbc: Subtract with carry

Logical¶

and rd, rn, rm: Bitwise AND orr rd, rn, rm: Bitwise OR eor rd, rn, rm: Bitwise XOR bic rd, rn, rm: Bit clear

Comparison¶

cmp rn, operand: Compare (sets N, Z, C, V flags) cmn rn, operand: Compare negative tst rn, operand: Test bits (N, Z flags) teq rn, operand: Test equivalence (N, Z flags)

Memory¶

ldr rd, =label: Load label address ldr rd, [rn]: Load word from memory str rd, [rn]: Store word to memory ldrb, strb: Byte variants

Branching¶

b label: Branch bl label: Branch with link (save return address) bx rn: Branch to address in register

Condition Codes¶

Execute instruction only if condition is true:

cmp r0, r1
bgt greater   ; Branch if r0 > r1

System¶

swi: Syscall (syscall number in r7) halt: Stop execution

See Instruction Set for complete reference.