loading of an exe or com
Posted: Fri Mar 28, 2003 6:12 pm
how is the loading of an exe or com file is done in,
lets say, dos ?
thanks
lets say, dos ?
thanks
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loading of an exe or com
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Re:loading of an exe or com
Posted: Fri Mar 28, 2003 10:13 pm
DOS loads the executable file from disk into memory, then performrms the execution of the app code via a jmp instruction.
Re:loading of an exe or com
Posted: Sat Mar 29, 2003 2:02 pm
this is exactly what i want to know, but how ?????
Re:loading of an exe or com
Posted: Sat Mar 29, 2003 4:47 pm
i would suggest you to read the "loader and linkers" online book (check the recommended reading sticky thread 
But *very* basically,
But *very* basically,
Code: Select all
int (run*)(void);
void* com=alloc(file_size("program.com"));
file_map(com,"program.com");
run=com;
return run();
Re:loading of an exe or com
Posted: Sat Mar 29, 2003 4:51 pm
well, DOS calls the BIOS to load sectors from the disk into memory, (bios int 13). then transfering processes execution with a jmp instruction to the location in memory where DOS told the bios to put the program. it dose't get any more simple than that.
Re:loading of an exe or com
Posted: Mon Apr 21, 2003 4:38 pm
Hi !
First u must Load the File into Memory and then Jump to its Start, the rest makes the File
First u must Load the File into Memory and then Jump to its Start, the rest makes the File
Re:loading of an exe or com
Posted: Tue Apr 22, 2003 2:48 pm
i look at a file as a chunk of memory that isnt accessible until put into memory. it can be code or data.