-rw-r--r-- 2937 saferewrite-20250228/README-elfulator raw
The line "c sparc elfulator: diet sparc-linux-gcc -Os" in ./compilers
will be skipped by default. Here's how to make this line work. Beware
that unrolling via elfulator increases costs; see README-resources.

All of these instructions are unprivileged, in the same account that's
running saferewrite. The instructions assume that you have already set
up a saferewrite environment and installed angr, and that you are in the
saferewrite directory.

Set up environment variables to use below:

   VENV=saferewrite
   BUILDROOT=buildroot-2024.11
   DIETLIBC=dietlibc-0.35
   export LIBRARY_PATH=$HOME/unicorn/build
   export LD_LIBRARY_PATH=$HOME/unicorn/build
   export CPATH=$HOME/unicorn/include

Download and run buildroot to compile sparc-linux-gcc:

   ( cd
     wget https://buildroot.org/downloads/$BUILDROOT.tar.xz
     tar -xf $BUILDROOT.tar.xz
     cd $BUILDROOT
     echo BR2_sparc=y > configs/sparc_defconfig
     make sparc_defconfig
     time make
   )

Link the cross-compiler into the saferewrite environment:

   ln -s $HOME/$BUILDROOT/output/host/bin/* $HOME/.virtualenvs/$VENV/bin/

Test cross-compiling and running a small program:

   ( echo '#include <stdio.h>'
     echo 'int main() { puts("works"); return 0; }'
   ) > ok.c
   sparc-linux-gcc -o ok ok.c -static
   ./ok

This should print "works". If you instead see "sparc-linux-gcc: command
not found", switch to the saferewrite environment---

   export PATH=$HOME/.virtualenvs/$VENV/bin:$PATH

---and then run the test again.

Download and compile dietlibc (plus a SPARC patch), first for amd64 and
then for 32-bit SPARC:

   ( cd
     wget https://www.fefe.de/dietlibc/$DIETLIBC.tar.xz
     tar -xf $DIETLIBC.tar.xz
     cd $DIETLIBC
     sed -i 's/glob /globl /' sparc/memcmp.S
     time make -j8
     time make -j8 ARCH=sparc CROSS=sparc-linux- CFLAGS='-Os -static' all
   )

Link the diet program into the saferewrite environment:

   ln -s $HOME/$DIETLIBC/bin-sparc/diet $HOME/.virtualenvs/$VENV/bin/

Test cross-compiling and running with dietlibc:

   diet sparc-linux-gcc -o ok ok.c
   ./ok

This should again print "works".

Download unicorn, switch to the version that these instructions were
tested with, apply a patch, and compile:

   cp unicorn-patch $HOME
   ( cd
     git clone https://github.com/unicorn-engine/unicorn.git
     cd unicorn
     git checkout 8a2846369c4070c948d8b1d3b84069de4a686b1c
     patch -p1 < ../unicorn-patch
     mkdir build
     cd build
     cmake .. -DCMAKE_BUILD_TYPE=Release
     time make -j8
   )

Link the unicorn library into the saferewrite directory (the *PATH
variables aren't enough for saferewrite to use elfulator):

   ln -s $HOME/unicorn/build/libunicorn* .

In the saferewrite directory, compile elfulator:

   gcc -Os -o elfulator elfulator.c setjmp.s -lunicorn

Test running a dietlibc cross-compiled executable under elfulator:

   ./elfulator ok `wc -c < ok`

This should once again print "works".