use libelf to find code offset in the exe

build.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 set -euo pipefail
 
-CFLAGS="-Wall -Wextra -Wpedantic -std=c99 -O3"
+CFLAGS="-Wall -Wextra -Wpedantic -std=c99"
 
 echo "building mos6502..."
 cc $CFLAGS -o mos6502 mos6502.c
@@ -16,4 +16,16 @@ if command -v pkg-config >/dev/null; then
     fi
 else
     echo "pkg-config not found - skipping chip8..."
-fi
+fi
+
+if command -v pkg-config >/dev/null; then
+    LIBELF_FLAGS=$(pkg-config --cflags --libs libelf 2>/dev/null)
+    if [ $? -eq 0 ]; then
+        echo "building riscv64..."
+        cc $CFLAGS -o riscv64 riscv64.c $LIBELF_FLAGS
+    else
+        echo "raylib not found - skipping riscv64..."
+    fi
+else
+    echo "pkg-config not found - skipping riscv64..."
+fi