Refined the README

COMPILE.md

@@ -0,0 +1,32 @@
+Compiling
+----
+*for Pandora*
+
+ `mkdir build; cd build; cmake .. -DPANDORA=1; make`
+    
+*or for Other ARM Linux*
+
+ `mkdir build; cd build; cmake .. -DLD80BITS=1 -DNOALIGN=1; make`
+
+*or for x86 Linux*
+
+ `mkdir build; cd build; cmake .. ; make`
+
+*or use ccmake*
+
+Alternatively, you can use the curses-bases ccmake (or any other gui frontend for cmake) to select wich platform to use interactively.
+
+*use ccache if you have it*
+Add `-DUSE_CCACHE=1` if you have ccache (it's better if you plan to touch the sources)
+
+*to have a Trace Enabled build*
+To have a trace enabled build (warning, it will be slower), add `-DHAVE_TRACE=1` but you will need, at runtime, to have the [Zydis library](https://github.com/zyantific/zydis) library in your `LD_LIBRARY_PATH` or in the system lib folders.
+
+----
+
+Testing
+----
+A few tests are included.
+They can be launched with `ctest`
+They are very basic and don't test much for now.
+

README.md

@@ -6,7 +6,7 @@ Box86 will let run x86 Linux program (games) on non-x86 Linux, like ARM (needs t
 
 Also, Box86 use native version for some "system" libraries, like libc, libm, or SDL and OpenGL, leading to more performance and easier integration with host system.
 
-Most x86 Games needs OpenGL, so on ARM platform, a solution like gl4es is probably needed.
+Most x86 Games needs OpenGL, so on ARM platform, a solution like [gl4es](https://github.com/ptitSeb/gl4es) is probably needed.
 
 Note that current version of Box86 doesn't feature any form of JIT/Dynarec: expect everything to be slow.
 
@@ -17,10 +17,30 @@ To have the TRACE enabled (i.e. dumping to stdout all individual x86 instruction
 
 Some x86 internal opcode use parts of "Realmode X86 Emulator Library", see [x86primop.c](src/x86primop.c) for copyright details
 
-Change log is accessible [here](CHANGELOG.md)
-
 Here are 2 videos, one of "Airline Tycoon Deluxe" running on an gigahertz OpenPandora, and the other of "Bit.Trip.Runner" running on an ODroid XU4.
 
 [![Play on Youtube](https://img.youtube.com/vi/bLt0hMoFDLk/3.jpg)](https://www.youtube.com/watch?v=bLt0hMoFDLk) [![Play on Youtube](https://img.youtube.com/vi/8hr71S029Hg/1.jpg)](https://www.youtube.com/watch?v=8hr71S029Hg)
 
+----
+
+Compiling
+----
+How to compile can be found [here](COMPILE.md)
+
+----
+
+Usage
+----
+
+There are a few environnement variable to control Box86 behavour.
+
+See [here](USAGE.md) for all variables and what they do.
+----
+
+Version history
+----
+
+The change log is [here](CHANGELOG.md)
+
+
 (If you use Box86 in your project, please don't forget to mention Box86)

USAGE.md

@@ -0,0 +1,46 @@
+Usage
+----
+
+There are many environnement variable to control Box86 behavour. 
+
+##### BOX86_LOG
+Controls the Verbose level of the log
+ * 0
+ * NONE : No message (exept some fatal error)
+ * 1
+ * INFO : Current default. Show some log
+ * 2
+ * DEBUG : Verbose a lot of stuffs (like relocations or function called)
+ * 3
+ * DUMP : All DEBUG plus DUMP of all ELF Info
+
+#### BOX86_LD_LIBRARY_PATH
+Controls the folder scanned to look for x86 libs. Default is current folder and `lib` in current folder.
+Also `/usr/lib/i386-linux-gnu` and `/lib/i386-linux-gnu` are added if they exists
+
+#### BOX86_PATH
+Controls the folder scanned to look for x86 executable. Default is current folder and `bin` in current folder.
+
+#### BOX86_DLSYM_ERROR
+* 0 : default. Don't log `dlsym` error
+* 1 : Log dlsym error
+
+#### BOX86_TRACE_FILE
+Send all log and trace to a file instead of `stdout`
+
+#### BOX86_TRACE
+Only on build with trace enabled. Trace allow the logging of all instruction execute, along with register dump
+* 0 : No trace
+* 1 : Trace enabled. The trace start after the init off all depending libs is done
+* symbolname : Trace only `symbolname` (trace is disable if the symbol is not found)
+* 0xXXXXXXX-0xYYYYYYY : trace only between the 2 addresses
+
+#### BOX86_TRACE_START
+Only on build with trace enabled.
+* NNNNNNN : Start trace anly after NNNNNNNN opcode execute (number is an `uint64_t`)
+
+#### BOX86_TRACE_XMM
+Only on build with trace enabled.
+* 0 : Default, the XMM (i.e. SSE/SSE2) register will not be logged with the general and x87 registers
+* 1 : Dump the XMM registers
+