cstool: update README with more details

HACK.TXT

@@ -16,6 +16,7 @@ Capstone source is organized as followings.
 │   ├── ocaml       <- Ocaml bindings + test code
 │   └── python      <- Python bindings + test code
 ├── contrib         <- Code contributed by community to help Capstone integration
+├── cstool          <- Cstool
 ├── docs            <- Documentation
 ├── include         <- API headers in C language (*.h)
 ├── msvc            <- Microsoft Visual Studio support (for Windows compile)
@@ -34,6 +35,10 @@ the code and try to recompile/reinstall again. This can be done with:
 	$ ./make.sh
 	$ sudo ./make.sh install
 
+Then test Capstone with cstool, for example:
+
+	$ cstool x32 "90 91"
+
 At the same time, for Java/Ocaml/Python bindings, be sure to always use
 the bindings coming with the core to avoid potential incompatibility issue
 with older versions.

cstool/README

@@ -1,7 +1,26 @@
-This directory contains cstool of capstone engine.
-To compile, simply run "make" on commandline. And after that, you could use 
-./cstool <arch+mode> <assembler-string> [start-address-in-hex-format]
-to use directly capstone engine.
+This directory contains cstool of Capstone Engine.
 
-To see <arch+mode> options are supported, you could input ./cstool 
+Cstool is a command-line tool to disassemble assembly hex-string.
+For example, to decode a hexcode string for Intel 32bit, run:
+
+	$ cstool x32 "90 91"
+
+	0	90	nop
+	1	91	xchg	eax, ecx
+
+Cstool disassembles the input and prints out the assembly instructions.
+On each line, the first column is the instruction offset, the second
+column is opcodes, and the rest is the instruction itself.
+
+Cstool is flexible enough to accept all kind of hexcode format. The following
+inputs have the same output with the example above.
+
+	$ cstool x32 "0x90 0x91"
+	$ cstool x32 "\x90\x91"
+	$ cstool x32 "90,91"
+	$ cstool x32 "90;91"
+	$ cstool x32 "90+91"
+	$ cstool x32 "90:91"
+
+To see all the supported options, run ./cstool