What does these every instruction mean in MIPS ? Dump of assembler code for func

Question

What does these every instruction mean in MIPS ? Dump of assembler code for function main: 0x080484f4 : push %ebp 0x080484f5 : mov %esp,%ebp 0x080484f7 : and $0xfffffff0,%esp 0x080484fa : sub $0x220,%esp 0x08048500 : mov %gs:0x14,%eax 0x08048506 : mov %eax,0x21c(%esp) 0x0804850d : xor %eax,%eax 0x0804850f : mov $0x8048690,%eax 0x08048514 : mov %eax,(%esp) 0x08048517 : call 0x80483f0 0x0804851c : mov $0x80486a5,%eax 0x08048521 : lea 0x11d(%esp),%edx 0x08048528 : mov %edx,0x4(%esp) 0x0804852c : mov %eax,(%esp) 0x0804852f : call 0x8048420 0x08048534 : mov $0x80486a8,%eax 0x08048539 : mov %eax,(%esp) 0x0804853c : call 0x80483f0 0x08048541 : mov $0x80486a5,%eax 0x08048546 : lea 0x1e(%esp),%edx 0x0804854a : mov %edx,0x4(%esp) ---Type to continue, or q to quit---

Explanation / Answer

push ebp  

saves the base pointer(EBP) and sets it to point to the top of the stack. ebp is used to access arguments.

mov ebp esp

and

sub esp 0x220  

reserves 0x220 bytes for space for local variables on the stack.

esp is used to index local varibles

mov gs eax gs is the segment register its use in linux canbe read up on basically used for per process data

mov eax (esp)   copies he value from %eax to the location in memory that %esp points to

xor eax eax setting eax to zero. returning zero

mov eax recognized by the system as read move eax 0x08048514

mov eax esp copies he value from %eax to the location in memory that %esp points to

call 0x0804851c

mov eax move the bytes in memory at the address contained

lea esp edx

lea is load effictive address this instruction places the address specified by its second operand into the register specified by its first operand

mov edx esp move the contents of the edx register into esp

mov eax esp copies he value from %eax to the location in memory that %esp points to

call 0x08048534

mov eax move the bytes in memory at the address contained
mov eax esp copies he value from %eax to the location in memory that %esp points to
call 0x08048541

move eax move the bytes in memory at the address contained

lea esp edx

lea is load effictive address this instruction places the address specified by its second operand into the register specified by its first operand

mov edx esp move the contents of the edx register into esp
quit

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.