disassembly

I'm self-studying how compilers works. I'm learning by reading the disassembly of GCC generated code from small 64-bit Linux programs. I wrote this C program: #include <stdio.h> int main() { for(int i=0;i<10;i++){ int k=0; } } After using objdump I get: 00000000004004d6 <main>: 4004d6: 55 push rbp 4004d7: 48 89 e5 mov rbp,rsp 4004da: c7 45 f8 00 00 00 00 mov DWORD PTR [rbp-0x8],0x0 4004e1: eb 0b jmp 4004ee <main+0x18> 4004e3: c7 45 fc 00 00 00 00 mov DWORD PTR [rbp-0x4],0x0 4004ea: 83 45 f8 01 add DWORD PTR [rbp-0x8],0x1 4004ee: 83 7d f8 09 cmp DWORD PTR [rbp-0x8],0x9 4004f2: 7e ef jle 4004e3

I need a helping hand in order to understand the following assembly instruction. It seems to me that I am calling a address at someUnknownValue += 20994A? E8 32F6FFFF - call std::_Init_locks::operator=+20994A Whatever you're using to obtain the disassembly is trying to be helpful, by giving the target of the call as an offset from some symbol that it knows about -- but given that the offset is so large, it's probably confused. The actual target of the call can be calculated as follows: E8 is a call with a relative offset. In a 32-bit code segment, the offset is specified as a signed 32-bit

I need something that can generate a PDB from a DLL file (C# .NET code), is there any free program to do that? You need the source code in order to generate a PDB. Even you have no sources and code obfuscated, you can create pdb by recompile with ildasm and ilasm: decompile assembly by ildasm : ildasm /out=assembly_name.il assembly_name.dll complile with ilasm : ilasm assembly_name.il /dll /pdb Stelio Actually you can do it also with dotPeek from 1.2 version onward. Right click the assembly in Assembly Explorer, and select "Generate Pdb". It also has the option to generate files for referenced

I am using the otool , nm and Fraise text editor to disassemble the Mach-o binaries. My workflow at this point is pretty straightforward: 1. List the existed symbols. nm -g 2. Get the disasm code. otool -vt 3. Copy and paste this output to a text file. 4. Read and comment the codes in the text editor :) I am looking for the tools that simplify the working with disasm code on Mac OS X . Peter Murphy You might want to try Hopper Disassemble r, osxdbg , Machoview , otx (otool GUI) and Affinic Debugger GUI . I als know of http://www.hopperapp.com/ , but never used it. (cannot be compared to Ida

this is fourth day I am trying to figure out how to break down an exe. Still having no luck, file is giving debugger error right after it is runned. I am using OllyDBG, it seems that file is either compressed or contains big ammount of data. I think it is just for debugging protection, however I can not get it working. I am trying to learn assembly and this is my "new level" achievment of getting better in testing applications. All I want to change is one text to other, inside the file exe. So this is one variable change. I would be satisfied even with simple number change inside it. Just want

I don't know x86 ASM very well, but I'm rather comfortable with SHARP-z80, and I know by experience that each instruction (mnemonic) has a corresponding byte/word value, and by looking at the hex dump of the assembled binary file I can "read back" the same code I wrote using mnemonics. In another SO question , somebody claimed that there are some situations where ASM instructions are not translated to their corresponding binary value, but instead are rearranged in a different way by the assembler . I'm looking especially for cases where disassembling the binary would result in a different ASM