What’s the difference between EAX, EBX, and ECX in assembly?
Nov 11, 2022 · 36 eax, ebx, ecx and so on are actually registers, which can be seen as "hardware" variables, somewhat similar to higher level-language's variables. Registers can be …
How exactly does the x86 LOOP instruction work? - Stack Overflow
Oct 23, 2017 · Use a smaller starting value for ecx so you get to the interesting ecx=1 part sooner. See also the x86 tag wiki for links to manuals, guides, and asm debugging tips at the bottom. …
assembly - Why take CMP ECX, ECX? - Stack Overflow
May 12, 2016 · 2 If the ECX register is zero then the repe cmpsb is not executed at all. This means that the following setb and seta instructions would produce garbage! Thus the …
What does X mean in EAX,EBX,ECX ... in assembly?
Mar 30, 2010 · The following is a brief explanation of what each of the x86 general-purpose registers stands for: EAX: "Extended Accumulator" - used for arithmetic and logical operations, …
assembly - How is "rax" different from "eax"? - Stack Overflow
Jul 7, 2017 · while in the book the registers are: eax, ecx, edx, ebx, esp, ebp, esi, edi, eip, eflags, cs, ss, ds, es, fs, gs Can someone explain why they are different? I'm running on an AMD cpu; …
The using rules of %eax, %edx, %ecx in the same function frame
Jul 14, 2020 · eax, ecx and edx are scratch registers, they don't have to be preserved across function calls. All other 32-bit general-purpose registers must be saved on the stack, which …
what are the purpose of different types of assembly registers?
Jun 10, 2014 · For example, rep stos instructions use ECX as a counter and stored data into the memory pointed to by EDI. Nowadays, specialized instructions like that are not as commonly …
Are the data registers EAX, EBX, ECX and EDX interchangeable
Nov 18, 2018 · For example, for the write system call, it grabs the file descriptor from ebx, a pointer to the buffer you want to write from ecx and the number of bytes you want to write from …
What is the correct way to loop if I use ECX in loop (Assembly)
Mar 19, 2017 · The advantage of loop is that it uses less instruction bytes. Think of it as a code-size optimization you can use if ECX happens to be a convenient register for looping, but at …
What is the purpose of XORing a register with itself?
Also to avoid 0s when compiled as used on shell codes for exploitation of buffer overflows, etc. Why avoid the 0 ? Well, 0 represents the end of string in c/c++ and the shell code would be …