Hi,

I need again help !!

I have create a simple library in C compiled with GCC in mylibusb.o

The code is :
#include <usb.h>
myusb_open(usb_dev_handle *udev)
{
   struct usb_bus *bus;
   struct usb_device *dev;
   char buff[64];
   int i;
   //Initialisation du bus USB
   usb_init();
   usb_find_busses();
   usb_find_devices();

for (bus = usb_busses; bus; bus = bus->next)
{
for (dev = bus->devices; dev; dev = dev->next)
{
if ((dev->descriptor.idVendor == 0x04D8) &&
(dev->descriptor.idProduct == 0x1985))
{

            udev = usb_open(dev);
         }

}

}
}

myusb_close(usb_dev_handle *udev)
{

   usb_close(udev);

}

myusb_write(usb_dev_handle *udev)
{

   usb_bulk_write(udev, 0x01, 0x01, 64, 1000);

}

I link this myusblib.o with my lazarus program :

unit usb_api;
interface
     function myusb_open(udev : thandle);cdecl;
     procedure myusb_close(udev : thandle) ; cdecl;
     procedure myusb_write(udev : thandle); cdecl;
implementation
{$link myusblib.o}
{$linklib usb}
{$linklib c}
{$linklib gcc}
uses CTypes;
function myusb_open; cdecl; external;
procedure myusb_close; cdecl; external;
procedure myusb_write; cdecl; external;
end.

and when I do

var
myhost : thandle;
begin
myusb_open(myhost);
myusb_write(myhost);
myusb_close(myhost);
end;

I have no communication with my usb board. My libusb.o work with the same program in C.

Have you got an idea on my problem or can you tell me if you have another solutions.

Is it possible to create a library Dll for windows and MAC OS and How can I do it with the libusb library?
Thanks you

Maybe you forgot the 'var':

  function myusb_open(var udev : thandle);cdecl;

?

I don't know your C macros (who knows?), but are you sure myusb_open is a function (or maybe a procedure)?

Mattias

I'm sorry,but what does 'cdecl' mean?
in fact i know nothing about how to import functions from external compiled library.
? 2009-05-26?? 14:15 +0200?Mattias Gaertner???

2009/5/26 Yan Chengyuan :

I'm sorry,but what does 'cdecl' mean? in fact i know nothing about how to import functions from external compiled library.

http://freepascal.org/docs-html/prog/progse22.html

i think osx has only one calling convention defined (per arch), so presumably it isn't necessary to specify cdecl.

henry

I'm going to try to add 'Var' in the declaration of my procedure. myusb_open is a procedure and not a fonction I have do an error of cut and paste..

I have always use 'cdecl' to declare external function but I'm not a pascal expert.

If you need more details to help me don't hesitate to ask me.

I thanks you.

I'm sorry,but what does 'cdecl' mean?
in fact i know nothing about how to import functions from external compiled library.
? 2009-05-26?? 14:15 +0200?Mattias Gaertner???

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