Questions tagged [executables]
For questions about executable binary files.
24 questions
13
votes
0
answers
348
views
What do “Cert DX2” strings embedded within some Windows drivers signify?
Executable formats used in Windows – PE, LE and NE – are extended from MS-DOS’s MZ executable format. This means that Windows binaries (including DLLs) can potentially be run as MS-DOS executables, ...
- 27.5k
8
votes
1
answer
1k
views
At which address does a COFF executable start executing?
I'm looking at some COFF files for the NS32k CPU, and was wondering where the OS starts executing a loaded program. The fields of the file header are:
unsigned short f_magic; // magic ...
- 767
17
votes
1
answer
1k
views
What was the PE subsystem value of 8 (`IMAGE_SUBSYSTEM_NATIVE_WINDOWS`) used for?
The Portable Executable format defines a header field that specifies the Windows subsystem under which the executable is meant to run. Typically it is used to declare the executable as being a GUI or ...
- 27.5k
18
votes
2
answers
2k
views
What was Borland Operating System Services (BOSS)?
The New Executable (NE) format used by 16-bit Windows and OS/2, and the multitasking ("European") MS-DOS 4, contains a "target operating system" field at byte offset 36h from the ...
- 3,998
4
votes
3
answers
1k
views
How to Extract Image Resource in Compilation?
How can image files be extracted from a compiled executable which contains certain resource files?
Precis on Resource Compilers
Visual C++ 1.5 did have a 16 bit console based resource compiler rc.exe ...
- 159
19
votes
4
answers
4k
views
Why did ancient Unix perform BSS segment initialization?
I just came across this good question at SO: Why are global and static variables initialized to their default values? But I don't like any of the answers and I actually think it remains unanswered: ...
- 1,024
4
votes
0
answers
158
views
What are the legal values at offset 0x30 in the Risc OS AIF header
I'm now poking around in the binary executable file format of the Acorn Archimedes family of computers, Arm Image Format or AIF.
It doesn't have a magic word but the *nix file utility identifies them ...
- 8,214
11
votes
2
answers
1k
views
What file format was used for binary executables on Motorola 680x0 Macintoshes?
Current macOS binary executable files use a format called "Mach-O" and prior to that there was the PEF "Preferred Object Format", and Wikipedia says "It was optimised for RISC ...
- 8,214
3
votes
2
answers
578
views
Why does my MZ executable's BSS inflate by ~1,5KB after linking fopen() with MSC?
For a game reversing project, I am trying to undo linking with the C library performed by the MSC 5.1 C compiler+linker.
To that end, I have created a simple executable that does nothing except ...
- 1,003
6
votes
1
answer
1k
views
Original purpose of the Rich Header in PE files
The Rich Header was presumably introduced by Microsoft in a previous version of Visual Studio. What was its original purpose and how does it achieve this? Is DanS the designer, similar to MZ?
- 1,995
4
votes
1
answer
542
views
Initial contents of CPU registers at OS/2 1.x program startup
What are the initial contents of CPU registers at OS/2 1.x program startup? I know that CS, IP, DS, SS and SP are initialized based on the NE header. But what about the other registers? Are they ...
- 5,499
12
votes
1
answer
726
views
How to write Win16 program with only a single segment (combined code+data)?
I wrote a simple Win16 program in NASM assembly. It works on Windows 3.11. (Source code: https://github.com/pts/mininasm/blob/master/demo/hello/helljw16.nasm .)
When I tried to combine the code and ...
- 5,499
14
votes
1
answer
2k
views
What was the purpose of the ‘overlay number’ field in the MZ executable format?
Many materials covering the layout of MZ executables (RBIL, for example, and even a comment in MS-DOS 2.0 source code) describe the word at offset +0x1a as the ‘overlay number’, with the value zero ...
- 27.5k
11
votes
1
answer
730
views
How can I properly execute and clean up after a DOS MZ executable loaded into memory with int21 function 4b01h?
Ralf Brown's Interrupt List describes a subvariant of the DOS int21/4Bh function with AL=01, where the program is loaded into memory and a PSP + stack are allocated for it, but the program is not ...
- 1,003
8
votes
0
answers
465
views
What is the origin of executable compression?
According to the wikipedia article on the topic, the earliest executable compressor listed is Realia Spacemaker for IBM PC (since 1982, written by Robert B. K. Dewar, SM.COM, signature "MEMORY$&...
- 22.3k