Nov 11, 2022 · Are EAX, EBX, and ECX just variables or do they all have a unique specific use other than storing values? These are the different processor registers. There are no variables in assembly language. You should read a thorough introduction into assembly to …

Four 32-bit data registers are used for arithmetic, logical, and other operations. These 32-bit registers can be used in three ways −. As complete 32-bit data registers: EAX, EBX, ECX, EDX. Lower halves of the 32-bit registers can be used as four 16-bit data registers: AX, BX, CX and DX.

Nov 19, 2013 · EAX 是"累加器" (accumulator), 它是很多加法乘法指令的缺省寄存器。 EBX 是"基地址" (base)寄存器, 在内存寻址时存放基地址。 ECX 是计数器 (counter), 是重复 (REP)前缀指令和LOOP指令的内定计数器。 EDX 则总是被用来放整数除法产生的余数。 ESI/EDI分别叫做"源/目标索引寄存器" (source/destination index),因为在很多字符串操作指令中, DS:ESI指向源串,而ES:EDI指向目标串. EBP是"基址指针" (BASE POINTER), 它最经常被用作高级语言函数调用 …

The first four integer parameters are passed in registers eax, ebx, ecx and edx. Floating point parameters are passed on the floating point stack – registers st0, st1, st2, st3, st4, st5 and st6. Structure parameters are always passed on the stack.

For the EAX, EBX, ECX, and EDX registers, subsections may be used. For example, the least significant 2 bytes of EAX can be treated as a 16-bit register called AX. The least significant byte of AX can be used as a single 8-bit register called AL, while the most significant byte of AX can be used as a single 8-bit register called AH.

Nov 25, 2016 · EAX: "Extended Accumulator" - used for arithmetic and logical operations, as well as for storing return values from functions. EBX: "Extended Base" - often used as a pointer to data in the data segment of memory.

Jan 1, 2024 · For example, 'EAX' is the accumulator register as a 32-bit value. Similarly, in the 64-bit version, the 'E' is replaced with an 'R' ( register ), so the 64-bit version of 'EAX' is called 'RAX'. It is also possible to address the first four registers (AX, CX, DX and BX) in their size of 16-bit as two 8-bit halves.

EDX: Data register, often used in conjunction with EAX for certain operations; Using Registers in Assembly. Registers are essential for performing operations in assembly. Here's a simple example of using registers to add two numbers: MOV EAX, 5 ; Load 5 into EAX MOV EBX, 3 ; Load 3 into EBX ADD EAX, EBX ; Add EBX to EAX, result stored in EAX

"mov" is an instruction, encoded with the operation code or "opcode" 0xb8. Since mov takes an argument, the next 4 bytes are the constant to move into eax. The opcode 0xb9 moves a constant into ecx. 0xba moves a constant into edx.

Nov 30, 2015 · EAX generally contains the return of a function. If you see the EAX register just after a function call, chances are that EAX contains the return value of the function. EAX and EDX are always implied in multiplication and division instructions; EAX can also be used as a temporary CPU memory for additions: