Embedding Files in an Executable - Linux/WSL2 - Part 1

1) Create data.txt

echo "Hello World" > data.txt

2) Convert data.txt to data.o

objcopy -I binary -O elf64-x86-64 -B i386 data.txt data.o

3) Get Symbols

hexdump -C data.o

000000b0  00 5f 62 69 6e 61 72 79  5f 64 61 74 61 5f 74 78  |._binary_data_tx|
000000c0  74 5f 73 74 61 72 74 00  5f 62 69 6e 61 72 79 5f  |t_start._binary_|
000000d0  64 61 74 61 5f 74 78 74  5f 65 6e 64 00 5f 62 69  |data_txt_end._bi|
000000e0  6e 61 72 79 5f 64 61 74  61 5f 74 78 74 5f 73 69  |nary_data_txt_si|
000000f0  7a 65 00 00 2e 73 79 6d  74 61 62 00 2e 73 74 72  |ze...symtab..str|
00000100  74 61 62 00 2e 73 68 73  74 72 74 61 62 00 2e 64  |tab..shstrtab..d|
00000110  61 74 61 00 00 00 00 00  00 00 00 00 00 00 00 00  |ata.............|
00000120  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|

_binary_data_txt_start
_binary_data_txt_end
_binary_data_txt_size

4) Create main.c

#include <stdio.h>

extern char _binary_data_txt_start;
extern char _binary_data_txt_end;

int main(){
   char* p = &_binary_data_txt_start;
   while ( p != &_binary_data_txt_end ) putchar(*p++);
   return 0;
}

5) Compile

gcc main.c data.o -o myprogram

6) Run

./myprogram

Compile windows exe

1) Install

sudo apt install gcc-mingw-w64-i686-win32
sudo apt install g++-mingw-w64-i686-win32

2) Test

i686-w64-mingw32-gcc --version
i686-w64-mingw32-g++ --version

3) Convert data.txt to data.o

i686-w64-mingw32-objcopy -I binary -O pe-i386 -B i386 data.txt data.o

4) Get Symbols

hexdump -C data.o

00000070  30 00 00 00 0c 00 00 00  ff ff 00 00 02 00 46 00  |0.............F.|
00000080  00 00 5f 62 69 6e 61 72  79 5f 64 61 74 61 5f 74  |.._binary_data_t|
00000090  78 74 5f 73 74 61 72 74  00 5f 62 69 6e 61 72 79  |xt_start._binary|
000000a0  5f 64 61 74 61 5f 74 78  74 5f 65 6e 64 00 5f 62  |_data_txt_end._b|
000000b0  69 6e 61 72 79 5f 64 61  74 61 5f 74 78 74 5f 73  |inary_data_txt_s|
000000c0  69 7a 65 00                               

5) Remove initial underscores

binary_data_txt_start
binary_data_txt_end
binary_data_txt_size

6) Create main.c or main.cpp

#include <stdio.h>

extern char binary_data_txt_start;
extern char binary_data_txt_end;

int main(){
   char* p = &binary_data_txt_start;
   while ( p != &binary_data_txt_end ) putchar(*p++);
   return 0;
}

#include <iostream>

extern char binary_data_txt_start;
extern char binary_data_txt_end;

int main(){
    char* p = &binary_data_txt_start;
    while (p != &binary_data_txt_end) std::cout << *p++;
    return 0;
}

7) Compile

i686-w64-mingw32-gcc main.c data.o -o main.exe
or
i686-w64-mingw32-g++ main.cpp data.o -o main.exe

Part 2

https://dev.to/gurigraphics/embedding-files-in-an-executable-windows-part-2-3gja