disassembly

问题 For example, with a boot sector that BIOS prints a to the screen main.asm : org 0x7c00 bits 16 cli mov ax, 0x0E61 int 0x10 hlt times 510 - ($-$$) db 0 dw 0xaa55 Then: nasm -o main.img main.asm qemu-system-i386 -hda main.img -S -s & gdb -ex \'target remote localhost:1234\' \\ -ex \'break *0x7c00\' \\ -ex \'continue\' \\ -ex \'x/3i $pc\' I get: 0x7c00: cli 0x7c01: mov $0x10cd0e61,%eax 0x7c06: hlt So it looks like the mov ax, 0x0E61 was interpreted as a 32-bit mov %eax and ate up the next

问题 I would like to translate X86_64, x86, ARM executables into LLVM IR (disassembly). What solution do you suggest ? 回答1: mcsema is a production-quality binary lifter. It takes x86 and x86-64 and statically "lifts" it to LLVM IR. It's actively maintained, BSD licensed, and has extensive tests and documentation. https://github.com/trailofbits/mcsema 回答2: Consider using RevGen tool developed within the S2E project. It allows converting x86 binaries to LLVM IR. The source code could be checked out

问题 I am studying Compilers course, compilation of program follows below steps Lexical analysis Syntax analysis Semantic analysis Intermediate code generation Code optimization Target code generation. How can I see output of each step e.g I want to see parse tree after syntax analysis. I am compiling program on Linux machine with GCC compiler. We can see assembly code of the program by using -Wa compiler option in gcc, similarly is there options to see Tokens, Parse tree and Inetmediate code. 回答1

问题 Is there anyway this can be done? I\'ve used objdump but that doesn\'t produce assembly output that will be accepted by any assembler that I know of. I\'d like to be able to change instructions within an executable and then test it afterwards. 回答1: I don't think there is any reliable way to do this. Machine code formats are very complicated, more complicated than assembly files. It isn't really possible to take a compiled binary (say, in ELF format) and produce a source assembly program which

问题 How can I see the assembly code for a C++ program? What are the popular tools to do this? 回答1: Ask the compiler If you are building the program yourself, you can ask your compiler to emit assembly source. For most UNIX compilers use the -S switch. If you are using the GNU assembler, compiling with -g -Wa,-alh will give intermixed source and assembly on stdout ( -Wa asks compiler driver to pass options to assembler, -al turns on assembly listing, and -ah adds "high-level source" listing): g++

问题 So I was googling for a long time and i found almost nothing. I found some info about possible implementation of Math.Pow from this url, but they are inaccurate, for example this code public static double PowerA(double a, double b) { int tmp = (int)(BitConverter.DoubleToInt64Bits(a) >> 32); int tmp2 = (int)(b * (tmp - 1072632447) + 1072632447); return BitConverter.Int64BitsToDouble(((long)tmp2) << 32); } static void Main(string[] args) { double x = 12.53, y = 16.45; Console.WriteLine(Math.Pow

问题 0x00000000004004b6 <main+30>: callq 0x400398 <printf@plt> Anyone knows? UPDATE Why two disas printf give me different result? (gdb) disas printf Dump of assembler code for function printf@plt: 0x0000000000400398 <printf@plt+0>: jmpq *0x2004c2(%rip) # 0x600860 <_GLOBAL_OFFSET_TABLE_+24> 0x000000000040039e <printf@plt+6>: pushq $0x0 0x00000000004003a3 <printf@plt+11>: jmpq 0x400388 (gdb) disas printf Dump of assembler code for function printf: 0x00000037aa44d360 <printf+0>: sub $0xd8,%rsp