5 ms·

I agree that it will be better if everything was open, but in the case of MenuetOS, I do not think it is so important ... the OS itself is written in assembler,

I agree that it will be better if everything was open, but in the case of MenuetOS, I do not think it is so important ... the OS itself is written in assembler, so the mapping between the final result in the binary of the OS, and its source is probably close to 1:1 .

exDM69 13y ago
> the OS itself is written in assembler, so the mapping between the final result in the binary of the OS, and its source is probably close to 1:1 Since Assembly code is pretty much unreadable, human-written Assembly source code tends to be 50-90% comments. Some OS related programming tasks are very handy to write with Assembler macros, that wouldn't be visible in the binary. In addition to the comments, the binaries might not contain variable names, function names and other useful information. Hell, even white space is important in Assembly sources! Those empty lines that separate a logical block of instructions or beginning and end of a loop, for example. The source code to a computer program written in Assembly is as important as source code in languages written in any other language. Binary blobs are not (effectively) readable by humans.
- delian66 13y ago
  What is your opinion on reversing highly optimized compiled high level code vs reversing manually written assembly code, starting from the resulting binary ? Having comments and human readable symbols like variable and function names is sure nice though.
  - exDM69 13y ago
    > What is your opinion on reversing highly optimized compiled high level code vs reversing manually written assembly code, starting from the resulting binary ? I don't want to do reverse-engineer either but I'd rather read the human written and compiled asm code. It's a little but not much better. I might read (and write) some assembly source code for fun, but I would not read the binaries so I'm going to stay away from this project.
  - techdragon 13y ago
    "Having comments and human readable symbols like variable and function names is sure nice though." Yes, and unfortunately given how unforgiving hard it can be for many programers to really sink their teeth into anything of significance using just assembly, those niceties are pretty much whats needed for anything of this size to be a practical example. Reverse engineering tools are not the nicest place to learn new programming techniques. :-(
    - delian66 13y ago
      Well, the source of the 32bit kernel is open, and anybody can study and learn from it: http://www.menuetos.org/M32.htm http://www.menuetos.org/M32.htm
  - comex 13y ago
    In IDA, Menuet would probably be really easy to reverse engineer for a two main reasons: - Very, very little code. Everything is implemented in the most minimal way possible. This is extremely important - you can literally read through all the code in the kernel from top to bottom and be sure you haven't missed any functionality. Good luck doing that with some 1MB C program. - Almost no indirection. Few indirect jumps, almost no use of malloc (!). In IDA this makes it very easy to name functions and variables and easily see where they are used, which isn't possible for anything dynamically allocated, as in idiomatic C. This is to some degree IDA's fault: a smarter tool could do a decent job at automatically inferring the types signatures of C functions and provide similar functionality for struct fields, but IDA does not. However, it does make the problem more tractable in general. Note that reading the actual assembly, at a local level, is missing from that list. If anything, compiler generated assembly is probably easier to read, due to recognizable idioms, although there are exceptions such as repetitive code in inline functions or templates that would never be written by a human. (The fun thing is, with a decompiler you can actually read the code in question as C.)
Someone 13y ago
Apart from the issues brought up by others: did you read the license? http://www.menuetos.net/m64l.txt http://www.menuetos.net/m64l.txt states: "Redistribution, reverse engineering, disassembly or decompilation prohibited without permission from the copyright holders."
- delian66 13y ago
  Yes, I read the license ... in fact I read both of them ... The license that you pointed, is for the 64bit version. However the MenuetOS 0.85C, for which the news item is about, is the 32bit version, and it is licensed under the GPL: http://www.menuetos.org/M32.htm http://www.menuetos.org/M32.htm

exDM69 13y ago

> the OS itself is written in assembler, so the mapping between the final result in the binary of the OS, and its source is probably close to 1:1 Since Assembly code is pretty much unreadable, human-written Assembly source code tends to be 50-90% comments. Some OS related programming tasks are very handy to write with Assembler macros, that wouldn't be visible in the binary. In addition to the comments, the binaries might not contain variable names, function names and other useful information. Hell, even white space is important in Assembly sources! Those empty lines that separate a logical block of instructions or beginning and end of a loop, for example. The source code to a computer program written in Assembly is as important as source code in languages written in any other language. Binary blobs are not (effectively) readable by humans.

delian66 13y ago
What is your opinion on reversing highly optimized compiled high level code vs reversing manually written assembly code, starting from the resulting binary ? Having comments and human readable symbols like variable and function names is sure nice though.
- exDM69 13y ago
  > What is your opinion on reversing highly optimized compiled high level code vs reversing manually written assembly code, starting from the resulting binary ? I don't want to do reverse-engineer either but I'd rather read the human written and compiled asm code. It's a little but not much better. I might read (and write) some assembly source code for fun, but I would not read the binaries so I'm going to stay away from this project.
- techdragon 13y ago
  "Having comments and human readable symbols like variable and function names is sure nice though." Yes, and unfortunately given how unforgiving hard it can be for many programers to really sink their teeth into anything of significance using just assembly, those niceties are pretty much whats needed for anything of this size to be a practical example. Reverse engineering tools are not the nicest place to learn new programming techniques. :-(
  - delian66 13y ago
    Well, the source of the 32bit kernel is open, and anybody can study and learn from it: http://www.menuetos.org/M32.htm http://www.menuetos.org/M32.htm
- comex 13y ago
  In IDA, Menuet would probably be really easy to reverse engineer for a two main reasons: - Very, very little code. Everything is implemented in the most minimal way possible. This is extremely important - you can literally read through all the code in the kernel from top to bottom and be sure you haven't missed any functionality. Good luck doing that with some 1MB C program. - Almost no indirection. Few indirect jumps, almost no use of malloc (!). In IDA this makes it very easy to name functions and variables and easily see where they are used, which isn't possible for anything dynamically allocated, as in idiomatic C. This is to some degree IDA's fault: a smarter tool could do a decent job at automatically inferring the types signatures of C functions and provide similar functionality for struct fields, but IDA does not. However, it does make the problem more tractable in general. Note that reading the actual assembly, at a local level, is missing from that list. If anything, compiler generated assembly is probably easier to read, due to recognizable idioms, although there are exceptions such as repetitive code in inline functions or templates that would never be written by a human. (The fun thing is, with a decompiler you can actually read the code in question as C.)

Someone 13y ago

Apart from the issues brought up by others: did you read the license? http://www.menuetos.net/m64l.txt http://www.menuetos.net/m64l.txt states: "Redistribution, reverse engineering, disassembly or decompilation prohibited without permission from the copyright holders."

delian66 13y ago
Yes, I read the license ... in fact I read both of them ... The license that you pointed, is for the 64bit version. However the MenuetOS 0.85C, for which the news item is about, is the 32bit version, and it is licensed under the GPL: http://www.menuetos.org/M32.htm http://www.menuetos.org/M32.htm