Byte: Today, a byte is almost always 8 bit. However, that wasn’t always the case and there’s no “standard” or something that dictates this. Since 8 bits is a convenient number to work with it became the de facto standard. Word: The natural size with which a processor is handling data (the register size). The most common word sizes … Read more
These two lines are your problem: eax is 32 bits, but both my1337Sk1LLz and Difference are 16 bits. There are two ways you might get around this: Changing the size of my1337Sk1LLz and Difference. Right now you have the types as WORD and SWORD, respectively. You can change those to DWORD and SDWORD to make … Read more
Alignment is important for a MIPS processor, it only likes to read multi-byte values from memory at an address that’s a multiple of the data size. The .ASCIIZ field can be placed anywhere since a string is read one byte at a time. So putting it at 0x10010003 is fine. The .WORD field must be … Read more
Brackets in [ESP+18h] mean that the destination of the MOV is memory location at ESP+18h. As an example, if ESP has value 10000000h, then your destination is memory location 10000018h. DWORD defines ‘size’ of the memory location used for move operation. In you example, you’d be moving 0000000Ah (4 bytes) into memory location ESP+18h. As … Read more
You’re missing a couple of loads, and your store is incorrect:
Actually you have only found the instruction, so it’s not ending there from your spec. Write out the machine code for the MIPS instruction. In order to write the machine code for this instruction you need to look at MIPS reference sheet MIPS Reference sheet If you look at the sheet the lw has opcode 35 and for $1 is 17 , … Read more
Can you please tell me the difference between JUMP IF ABOVE AND JUMP IF GREATER in Assembly language? when do i use each of them? do they give me different results?
The dword ptr part is called a size directive. This page explains them, but it wasn’t possible to direct-link to the correct section. Basically, it means “the size of the target operand is 32 bits”, so this will bitwise-AND the 32-bit value at the address computed by taking the contents of the ebp register and … Read more
Shifting a number n bits left multiples the number by 2n. For example n << 3 = n*2³ = n*8. The corresponding instruction is To multiply any number you can split the number into sums of power of 2s. For example: n*10 = n*8 + n*2 = (n << 3) + (n << 1) SLL … 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