What does the dollar sign ($) mean in x86 assembly when …
2012年4月28日 · NASM supports two special tokens in expressions, allowing calculations to involve the current assembly position: the $ and $$ tokens. $ evaluates to the assembly position at the beginning of the line containing the expression; so you can code an infinite loop using JMP $.
if statement - How to write if-else in assembly? - Stack Overflow
2016年11月15日 · 1. To use if statement in NASM assembly first line should write: comp eax, ebx. In this line NASM understands that it should compare two registers. Now u should specify how NASM assembly should compare them. Lets compare for example if greater or equal: main: comp eax, ebx. jge greater_or_equal.
How to write hello world in assembly under Windows?
2009年6月21日 · message: db 'Hello, World', 10, 0. Then run. nasm -fwin32 helloworld.asm. gcc helloworld.obj. a. There's also The Clueless Newbies Guide to Hello World in Nasm without the use of a C library. Then the code would look like this. 16-bit code with MS-DOS system calls: works in DOS emulators or in 32-bit Windows with NTVDM support.
What does the 'and' instruction do to the operands in assembly …
2018年12月4日 · The instruction and performs bit-wise AND operation on its operands. For example the instruction and al, bl should compute the AND operation on the register al and bl (as illustrated by @Serkratos121) and store the result in al register.
Assembly difference between [var], and var - Stack Overflow
2017年3月2日 · 15. In x86 Intel syntax [expression] means content of memory at address expression. expression without brackets depends on Assembler you are using. NASM-style (NASM, YASM): MASM-style (also TASM and even GCC/GAS .intel_syntax noprefix): GAS (AT&T syntax): It's not Intel syntax, see the AT&T tag wiki.
What is the difference between MOV and LEA? - Stack Overflow
LEA means Load Effective Address. MOV means Load Value. In short, LEA loads a pointer to the item you're addressing whereas MOV loads the actual value at that address. The purpose of LEA is to allow one to perform a non-trivial address calculation and store the result [for later usage] LEA ax, [BP+SI+5] ; Compute address of value.
assembly - Difference between JE/JNE and JZ/JNZ - Stack Overflow
6. JE means jump if equal, it is equal if a prior compare has the z flag set, JZ means jump if the z flag is set. They are exactly the same, some folks want to think/write in terms of my compare was equal or not equal. Some folks think and write in terms of is …
hardware - How do assembly languages work? - Stack Overflow
2016年6月16日 · The assembler converts it into machine code. This process depends on both the particular assembly language and the target computer architecture. Generally those go hand in hand, but you might find different flavors of assembly language (nasm vs. AT&T, for example), which all translate into similar machine code.
x86 - What does ORG Assembly Instruction do? - Stack Overflow
2020年6月11日 · 1. ORG (abbr. for ORiGin) is an assembly directive and is not an instruction. It defines where the machine code (translated assembly program) is to place in memory. As for ORG 100H this deals with 80x86 COM program format (COMMAND) which consists of only one segment with a maximum of 64k bytes.
What does bx lr do in ARM assembly language? - Stack Overflow
2014年11月23日 · bx stands for branch and exchange instruction set Which means that according to the lsb (least significant bit) of the address to branch to, the processor will treat the next instruction as ARM or as thumb. As lr usually holds the return address, it means that this is a return from a function, and if the lsb of lr is 1, it will treat the code ...