REVE1 Logs

Use gcc -S to emit assembly text from C source, or objdump -d / GDB's disassemble to read the machine code back out of a compiled binary. There are two directions, and both are essential for reverse engineering practice: Forward — C to assembly text: gcc -S -O2 example.c...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

Because do-while — "run the body, then conditionally jump back" — is the only loop shape the hardware directly provides; everything else is built on top of it. Hardware offers straight-line execution plus conditional branches. The do-while pattern maps onto that with zero overhea...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

Poor ordering scatters padding between members; ordering members from largest/strictest alignment to smallest packs them tightly and shrinks the struct. * Member ordering changes padding: declare fields in decreasing alignment order to shrink the struct. * Because each member mu...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

Caller-saved: the called function is free to clobber them, so the caller must save anything it still needs. Callee-saved: the function must preserve them, restoring their original values before returning. * Caller-saved may be clobbered by the callee (temporaries); callee-saved...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

They sign-extend the value in %rax/%eax into the full %rdx:%rax/%edx:%eax pair, building the high half a signed idiv requires. * cqto sign-extends rax into rdx to build the 128-bit rdx:rax dividend; unsigned div zeroes rdx with xor instead. * x86 signed division (idivq) divides...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

Assembly has no high-level constructs at all — every loop, branch, and data structure dissolves into compares, jumps, and fixed memory offsets that the compiler computes ahead of time. The whole topic reduces to three lessons about what disappears when C becomes machine code: Con...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

x/NFU address — examine N items, in Format (x=hex, d=dec, i=instruction, s=string…), of Unit size (b/h/w/g = 1/2/4/8 bytes) — starting at address. GDB's x is the Swiss-army knife for inspecting raw memory while reverse-engineering. The count, format, and unit are bundled into one...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

lea computes an address expression and stores the address itself — it does not read memory, and unlike arithmetic it leaves the condition flags untouched. * lea computes an address (no memory access, no flags set) while mov dereferences it; lea doubles as cheap multiply-add. * l...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

Each j<cc> jumps based on the flags from the preceding cmp/test; signed comparisons use g/l (greater/less), unsigned use a/b (above/below). * Conditional jumps after cmp fall into signed, unsigned, and equality families; seeing ja/jb signals an unsigned type. * After cmp b, a (w...

Quiz: REVE1 / Translation of C to Assembly | updated: Jul 30, 2026

It specifies which variables from the surrounding scope the lambda can use — and whether it grabs each by value (a copy) or by reference. Capture Meaning [] Capture nothing [x] Capture x by value (copy) [&x] Capture x by reference [=] Capture all used variables by va...

Quiz: REVE1 / C++ Programming | updated: Jul 30, 2026