Machine Code
TLDR: Machine code is the lowest-level representation of a computer program, consisting of binary instructions executed directly by a computer's CPU. Introduced in the early days of computing in the mid-20th century, machine code is generated from high-level programming languages or assembly language by compilers or assemblers. Each instruction in machine code corresponds to a specific operation, such as arithmetic, memory access, or control flow, that the processor can perform.
https://en.wikipedia.org/wiki/Machine_code
Machine code is hardware-specific, meaning the instructions are tailored to the architecture of a particular CPU, such as x86, ARM, or RISC. Unlike high-level programming languages, machine code lacks readability and portability, making it challenging for humans to write or debug directly. However, understanding machine code is crucial in certain domains, such as low-level debugging, embedded systems, and performance optimization, where precise control over hardware is required. Tools like disassemblers and hex editors aid in analyzing and modifying machine code.
https://www.gnu.org/software/binutils/
In modern software development, machine code is typically an intermediate product of compilation, with developers relying on high-level programming languages to write source code. However, it plays a vital role in ensuring that programs run efficiently on target hardware. For example, compilers optimize machine code to minimize instruction cycles and improve CPU utilization. Additionally, knowledge of machine code is indispensable in reverse engineering, allowing experts to analyze software behavior and security vulnerabilities.
https://docs.oracle.com/en/java/javase/20/troubleshooting/debugging-overview.html
- Snippet from Wikipedia: Machine code
In computing, machine code is data encoded and structured to control a computer's central processing unit (CPU) via its programmable interface. A computer program consists primarily of sequences of machine-code instructions. Machine code is classified as native with respect to its host CPU since it is the language that CPU interprets directly. A software interpreter is a virtual machine that processes virtual machine code.
A machine-code instruction causes the CPU to perform a specific task such as:
- Load a word from memory to a CPU register
- Execute an arithmetic logic unit (ALU) operation on one or more registers or memory locations
- Jump or skip to an instruction that is not the next one
An instruction set architecture (ISA) defines the interface to a CPU and varies by groupings or families of CPU design such as x86 and ARM. Generally, machine code compatible with one family is not with others, but there are exceptions. The VAX architecture includes optional support of the PDP-11 instruction set. The IA-64 architecture includes optional support of the IA-32 instruction set. And, the PowerPC 615 can natively process both PowerPC and x86 instructions.