1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
# Compiling simple_target.c
You shouldn't need to compile simple_target.c since a MIPS binary version is
pre-built and shipped with afl-unicorn. This file documents how the binary
was built in case you want to rebuild it or recompile it for any reason.
The pre-built binary (simple_target.bin) was built by cross-compiling
simple_target.c for MIPS using the mips-linux-gnu-gcc package on an Ubuntu
16.04 LTS system. This cross compiler (and associated binutils) was installed
from apt-get packages:
```
sudo apt-get install gcc-mips-linux-gnu
```
simple_target.c was compiled without optimization, position-independent,
and without standard libraries using the following command line:
```
mips-linux-gnu-gcc -o simple_target.elf simple_target.c -fPIC -O0 -nostdlib
```
The .text section from the resulting ELF binary was then extracted to create
the raw binary blob that is loaded and emulated by simple_test_harness.py:
```
mips-linux-gnu-objcopy -O binary --only-section=.text simple_target.elf simple_target.bin
```
In summary, to recreate simple_taget.bin execute the following:
```
mips-linux-gnu-gcc -o simple_target.elf simple_target.c -fPIC -O0 -nostdlib
&& mips-linux-gnu-objcopy -O binary --only-section=.text simple_target.elf simple_target.bin
&& rm simple_target.elf
```
Note that the output of this is padded with nulls for 16-byte alignment. This is
important when emulating it, as NOPs will be added after the return of main()
as necessary.
|
