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+The perl scripts in this directory are my 'hack' to generate
+multiple different assembler formats via the one origional script.
+
+The way to use this library is to start with adding the path to this directory
+and then include it.
+
+push(@INC,"perlasm","../../perlasm");
+require "x86asm.pl";
+
+The first thing we do is setup the file and type of assember
+
+&asm_init($ARGV[0],$0);
+
+The first argument is the 'type'.  Currently
+'cpp', 'sol', 'a.out', 'elf' or 'win32'.
+Argument 2 is the file name.
+
+The reciprocal function is
+&asm_finish() which should be called at the end.
+
+There are 2 main 'packages'. x86ms.pl, which is the microsoft assembler,
+and x86unix.pl which is the unix (gas) version.
+
+Functions of interest are:
+&external_label("des_SPtrans"); declare and external variable
+&LB(reg);                       Low byte for a register
+&HB(reg);                       High byte for a register
+&BP(off,base,index,scale)       Byte pointer addressing
+&DWP(off,base,index,scale)      Word pointer addressing
+&stack_push(num)                Basically a 'sub esp, num*4' with extra
+&stack_pop(num)                 inverse of stack_push
+&function_begin(name,extra)     Start a function with pushing of
+                                edi, esi, ebx and ebp.  extra is extra win32
+                                external info that may be required.
+&function_begin_B(name,extra)   Same as norma function_begin but no pushing.
+&function_end(name)             Call at end of function.
+&function_end_A(name)           Standard pop and ret, for use inside functions
+&function_end_B(name)           Call at end but with poping or 'ret'.
+&swtmp(num)                     Address on stack temp word.
+&wparam(num)                    Parameter number num, that was push
+                                in C convention.  This all works over pushes
+                                and pops.
+&comment("hello there")         Put in a comment.
+&label("loop")                  Refer to a label, normally a jmp target.
+&set_label("loop")              Set a label at this point.
+&data_word(word)                Put in a word of data.
+
+So how does this all hold together?  Given
+
+int calc(int len, int *data)
+        {
+        int i,j=0;
+
+        for (i=0; i<len; i++)
+                {
+                j+=other(data[i]);
+                }
+        }
+
+So a very simple version of this function could be coded as
+
+        push(@INC,"perlasm","../../perlasm");
+        require "x86asm.pl";
+        
+        &asm_init($ARGV[0],"cacl.pl");
+
+        &external_label("other");
+
+        $tmp1=  "eax";
+        $j=     "edi";
+        $data=  "esi";
+        $i=     "ebp";
+
+        &comment("a simple function");
+        &function_begin("calc");
+        &mov(   $data,          &wparam(1)); # data
+        &xor(   $j,             $j);
+        &xor(   $i,             $i);
+
+        &set_label("loop");
+        &cmp(   $i,             &wparam(0));
+        &jge(   &label("end"));
+
+        &mov(   $tmp1,          &DWP(0,$data,$i,4));
+        &push(  $tmp1);
+        &call(  "other");
+        &add(   $j,             "eax");
+        &pop(   $tmp1);
+        &inc(   $i);
+        &jmp(   &label("loop"));
+
+        &set_label("end");
+        &mov(   "eax",          $j);
+
+        &function_end("calc");
+
+        &asm_finish();
+
+The above example is very very unoptimised but gives an idea of how
+things work.
+
+There is also a cbc mode function generator in cbc.pl
+
+&cbc(   $name,
+        $encrypt_function_name,
+        $decrypt_function_name,
+        $true_if_byte_swap_needed,
+        $parameter_number_for_iv,
+        $parameter_number_for_encrypt_flag,
+        $first_parameter_to_pass,
+        $second_parameter_to_pass,
+        $third_parameter_to_pass);
+
+So for example, given
+void BF_encrypt(BF_LONG *data,BF_KEY *key);
+void BF_decrypt(BF_LONG *data,BF_KEY *key);
+void BF_cbc_encrypt(unsigned char *in, unsigned char *out, long length,
+        BF_KEY *ks, unsigned char *iv, int enc);
+
+&cbc("BF_cbc_encrypt","BF_encrypt","BF_encrypt",1,4,5,3,-1,-1);
+
+&cbc("des_ncbc_encrypt","des_encrypt","des_encrypt",0,4,5,3,5,-1);
+&cbc("des_ede3_cbc_encrypt","des_encrypt3","des_decrypt3",0,6,7,3,4,5);
+