navmv

Noah's Assembly Virtual Machine - V

syntax

The assembler follows Intel Syntax, meaning

• Destination before source | mov ax, 5

In a call with two operands, the first must always be a valid register.

registers

ax, bx, cx, and dx.

Each register can hold an integer or string value.

constants

Constants are declared in the .data section of the program, and can be referenced within the program using [NAME].

Constants cannot be reassigned at runtime.

variables

Variables can only be assigned through user input, and can be referenced within the program using [NAME]. However, at initial assignment, they are referenced by NAME.

opcodes

mov : moves the source value into the destination register.

cmp : compares two values. Sets the PSW flag to 1 if true.

add : adds the source value to the destination register.

sub : subtracts the source value from the destination register.

mul : multiplies the destination register by the source value.

div : divides the destination register by the source value.

mod : moves the remainder of destination/source to the destination register.

shl : left-shifts the destination register by the source value.

shr : right-shifts the destination register by the source value.

xor : xor's

inc : increments the destination register by 1.

dec : decrements the destination register by 1.

jmp : jumps to the specified label.

jnz : if the previous line is not zero, jumps to the specified label.

jz : if the previous line is zero, jumps to the specified label.

je : if the PSW flag is 1, jumps to specified label.

jne : if the PSW flag is 0, jumps to the specified label.

prn : prints the ASCII equivalent of an integer.

hlt : halts the assembler.

push : pushes the provided register to the runtime stack.

pop : pops the runtime stack into the given register.

ret : returns to where the function was called.

call : jump to the beginning of the specified function.

syscall : make a syscall (read, write, etc)

nop : do nothing.

xchg : exchange the values in the destination and source registers.

dbg : print a debug message.