Ye, You'll need to provide more details about what you are trying to accomplish before you are likely to get much information. In particular, what kind of communication path are you trying to set up. Here are a few questions to help you narrow the scope of your request: 1) Are you just trying find & configure your driver from an app, or are you really moving data? 2) Is the data low-bandwidth data, or high-bandwidth? (KB/sec, MB/sec, ...) 3) How much latency can be tolerated on the data path? (usec, msec, sec, ...) 4) Is the data flow symmetric, mostly into the computer, or mostly out of the computer? 5) Is the data managed in large chunks (KB, MB at a time) or small chunks (bytes at a time)? Some additional questions that will help in identifying appropriate sample code: 6) Does your device fit into any existing device families? 7) Do you need to support multiple devices/data streams? 8) Are there any IPC models you are already familiar with such as Mach Messaging (MiG), BSD-style /dev nodes (open/close/read/write/ioctl), BSD sockets? In general, you will find you get more useful answers on this discussion group if you provide lots of details about what you are trying to do. You will also find the search engine at http://developer.apple.com to be very helpful. Hope this helps, - Dean On Apr 14, 2004, at 7:54 PM, yetty wrote: Dir Sir/Madam, Our company are going to develop software on Mac OS X. And now I am doing the research for it to confirm whether we can do it. Actually there are many difficulties. With this letter I will ask a question about Accessing Hardware from applications. In the document "Hello Kernel: Creating a Kernel Extension With Project Builder" you have give an example of kernel programming.The sample code is the following: #include <sys/systm.h> #include <mach/mach_types.h> kern_return_t HelloKernel_start (kmod_info_t * ki, void * d) { printf("KEXT has loaded!\n"); return KERN_SUCCESS; } kern_return_t HelloKernel_stop (kmod_info_t * ki, void * d) { printf("KEXT will be unloaded\n"); return KERN_SUCCESS; } And also I have done as the document "Packaging Your KEXT for Distribution and Installation" says. My question is that how can I access the module HelloKernel from application. I have read your document "Accessing Hardware From Applications". But I think the document is too difficult. So Can you give me an example of accessing the HelloKernel from application? Thanks! yours sincerely Ye Wenxi in Tokyo _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.