What is EAX x86?

eax. eax is a 32-bit general-purpose register with two common uses: to store the return value of a function and as a special register for certain calculations. It is technically a volatile register, since the value isn’t preserved. Instead, its value is set to the return value of a function before a function returns.

Subsequently, question is, what is x86 used for? x86 is a term used to describe a CPU instruction set compatible with the Intel 8086 and its successors, including the Pentium and others made by Intel and other companies. This is the CPU architecture used in most desktop and laptop computers. Many 21st century workstations and servers also use x86 processors.

are EAX and Rax the same?

rax is the 64-bit, “long” size register. It was added in 2003 during the transition to 64-bit processors. eax is the 32-bit, “int” size register.

What is x86 code?

x86 Assembly Language is a family of backward-compatible assembly languages, which provide some level of compatibility all the way back to the Intel 8008 introduced in April 1972. x86 assembly languages are used to produce object code for the x86 class of processors.

What is mov eax?

Assembly language is a programming language. A feature of assembly language is that each line in the source code usually contains a single instruction to the processor, for example MOV EAX,EDX will move the content of the EDX register into the EAX register. Here the “MOV” instruction is called a “mnemonic”.

How can I learn assembler?

Regardless of which machine or emulator you choose to learn it on, ensure that you: Understand how a high level program gets compiled down to assembly and/or machine language. Understand the machine’s hardware architecture. See what high level languages like C get compiled down to on that architecture, if possible.

What happens when RET instruction is executed?

The RET instruction pops the return address off the stack (which is pointed to by the stack pointer register) and then continues execution at that address. The RET instruction pops the return address off the stack (which is pointed to by the stack pointer register) and then continues execution at that address.

What is ESP in stack?

The stack pointer: ESP register contents The register ESP (literally “extended stack pointer”) holds the top of the stack. This is the point where the instructions which use the stack (PUSH, POP, CALL and RET) actually use the stack.

What is push instruction?

The PUSH instruction saves the current PRINT, USING, or ACONTROL status in push-down storage on a last-in, first-out basis. You restore this PRINT, USING, or ACONTROL status later, also on a last-in, first-out basis, by using a POP instruction.

What is push in assembly?

The push instruction places its operand onto the top of the hardware supported stack in memory. Specifically, push first decrements ESP by 4, then places its operand into the contents of the 32-bit location at address [ESP].

What is call in assembly?

The call instruction is used to call a function. The CALL instruction performs two operations: It pushes the return address (address immediately after the CALL instruction) on the stack. It changes EIP to the call destination.

What is Al in assembly language?

EAX is the full 32-bit value AX is the lower 16-bits AL is the lower 8 bits AH is the bits 8 through 15 (zero-based)

What is EAX register?

eax is a 32-bit general-purpose register with two common uses: to store the return value of a function and as a special register for certain calculations.

What are x86 servers?

x86 is the generic name for Intel processors released after the original 8086 processor. These include the 286, 386, 486, and 586 processors. Technically, x86 is short for 80×86 since the full names of the processors are actually 80286, 80386, 80486, and 80586.

What is a 32 bit register?

32-bit and 64-bit are commonly used to describe processor architecture or design. A 32-bit processor includes a 32-bit register, which can store 232 or 4,294,967,296 values. A 64-bit register can theoretically reference 18,446,744,073,709,551,616 bytes, or 17,179,869,184 gigabytes (16 exabytes) of memory.

What is extra segment?

Extra Segment Register (ES) : also refers to a segment in the memory which is another data segment in the memory. Stack Segment Register (SS): is used for addressing stack segment of the memory. The stack segment is that segment of memory which is used to store stack data.

How many registers does a CPU have?

Many CPUs now have general purpose registers (GPRs), which may contain both data and memory addresses. Registers vary in both number and size, depending on the CPU architecture. Some processors have 8 registers while others have 16, 32, or more. For many years, registers were 32-bit, but now many are 64-bit in size.

How many bits are in the AX register?

16 bits