e195c8a256
The assembler already knows the actual path to the generated file and, in other perlasm architectures, is left to manage debug symbols itself. Notably, in OpenSSL 1.1.x's new build system, which allows a separate build directory, converting .pl to .s as the scripts currently do result in the wrong paths. This also avoids inconsistencies from some of the files using $0 and some passing in the filename. Reviewed-by: Richard Levitte <levitte@openssl.org> Reviewed-by: Andy Polyakov <appro@openssl.org> (Merged from https://github.com/openssl/openssl/pull/3431)
124 lines
3.3 KiB
Text
124 lines
3.3 KiB
Text
The perl scripts in this directory are my 'hack' to generate
|
|
multiple different assembler formats via the one original script.
|
|
|
|
The way to use this library is to start with adding the path to this directory
|
|
and then include it.
|
|
|
|
push(@INC,"perlasm","../../perlasm");
|
|
require "x86asm.pl";
|
|
|
|
The first thing we do is setup the file and type of assembler
|
|
|
|
&asm_init($ARGV[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 normal 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]);
|
|
|
|
&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);
|
|
|