ESP is the current stack pointer. EBP is the base pointer for the current stack frame. When you call a function, typically space is reserved on the stack for local variables. This space is usually referenced via EBP (all local variables and function parameters are a known constant offset from this register for the duration … Read more
Caller-saved registers (AKA volatile registers, or call-clobbered) are used to hold temporary quantities that need not be preserved across calls. For that reason, it is the caller’s responsibility to push these registers onto the stack or copy them somewhere else if it wants to restore this value after a procedure call. It’s normal to let … Read more
No, that’s not quite right. So AX is composed of AH:AL halves, and is itself the low half of EAX. (The upper half of EAX isn’t directly accessible as a 16-bit register; you can shift or rotate EAX if you want to get at it.) For completeness, in addition to the above, which was based … Read more
I keep seeing this form often: div 3, 15 this is not any valid INTEL mneumonic! To divide 15 by 3: For the second error, you cannot move a 16 bit register into a 32 bit register like that. You need to use one of the following: Or:
General purpose means all of these registers might be used with any instructions doing computation with general purpose registers while, for example, you cannot do whatever you want with the instruction pointer (RIP) or the flags register (RFLAGS). Some of these registers were envisioned to be used for specific use, and commonly are. The most … Read more
The origin of the code is x3700, and you have 12 instructions, so the address of A will be x3700 + x0C = x370C. As you guessed, LEA R0,A loads the address of A into R0, so R0 will contain x370C after that first instruction has been executed.
info registers shows all the registers; info registers eax shows just the register eax. The command can be abbreviated as i r