April 2002 - Darwin-kernel - lists.apple.com

Re: Asynchronous Data Transfer to a PCI Device
by Godfrey van der Linden 30 Apr '02

30 Apr '02

Who queued the Param blocks before? The user client async methods are usually not what you want! Asynchronous I/O 101. There seems to be a lot of confusion about what an asynchronous I/O operation is. So lets go back to 1st principals. An Asynchronous operation is one that can proceed without explicit CPU intervention. This frees the CPU to return to the 'main loop'. Then at some stage in the future the operation completes and causes some client code to execute. So to initiate an asyncrhonous operation you make a subroutine call to a driver somewhere. This call is 'synchronous', isn't it, by that I mean you expect the routine to return don't you? So use Xs synchronous routines to initiate an asynchronous I/O operation. Your email doesn't make clear, are you really POLLING on 'ioResult'. How often do you poll per second, can you measure this in your code please? This is very bad behaviour on X. On X we recommend the use of the Notification port API. First create a port with IONotificationPortCreate. Then register it with your driver using IOConnectSetNotificationPort(), this call calls IOUserClient::registerNotificationPort inside your driver. This sets the plumbing up from the kernel's point of view. Finally you need to plumb the completion call back into your 'mainloop'. This is pretty easy. Call IONotificationPortGetRunloopSource() then register the this source with your applications runloop. This is the general outline of your solution. We can go on from here as you get comfortable with this. Godfrey van der Linden an IOKit architect _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

Asynchronous Data Transfer to a PCI Device
by Peter Young 30 Apr '02

30 Apr '02

Hi, I am currently porting a C-based PCI Driver (OS9) to OS X. The driver controls one of several interface cards sending data to imagesetters. I have ported most of the control API and Serial comms API and am starting on the data transfer API. The OS9 driver code relied on the system to queue pending driver calls while it handled the current call. Immediate calls were handled directly by the driver and did not require queueing. Q1. Does OSX provide an equivalent mechanism, or do I have to provide my own internal queueing mechanism ? The OS9 client used the IOParam block and PBWriteAsync() to send data to the driver and then 'waited' for the driver to change IOParam.ioResult. What I need to do is to provide an equivalent mechanism under OSX. Q2. Are there any such samples available, or can someone shed light on how to do this ? The PCI DDK OSX v1.0 contains an AppleSamplePCI driver which appears to show a mechanism for providing this behaviour. The client uses an io_async_method... call to send data to the driver, and uses a callback to get notification of completion. The synchronous calls are made using the IOConnectMethod... set of calls, but there does not appear to be an equivalent IOAsyncConnectMethod... set. I eventually tracked the io_async_method... APIs to iokitmig_c.h. Q4. Do the IOAsyncConnect... APIs exist, and if so where are they in the IOKit headers ? Q3. Will the io_async_... APIs be available for some time, or are they, as the file name iokitmig_c.h suggests, something that is undergoing change ? I don't want to waste time making it work, if in three months time the calls are going to disappear. The driver method uses sendAsyncResult() to trigger the callback, passing the appropriate return code, and any required parameters. it then returns kIOReturnSuccess to the original call. In my case, I must assume that the driver method hands off the data to another thread to perform the actual transfer and then trigger the completion routine appropriately, while the method itself returns to the caller with a suitable completion code. This presupposes that I have a separate thread running which is holding all the queued calls until the output thread can process them. Any assistance gratefully received. Thanks in advance Peter Young Development Engineer, HighWater Designs Ltd. _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

Re: OS X <--> Darwin Tag Mappings?
by Justin C. Walker 26 Apr '02

26 Apr '02

On Friday, April 26, 2002, at 08:57 AM, Jacob Shaw wrote: Hi, I'd like an RTFM on how Darwin tags (eg. 201-9-1) map to OS X releases. You and everyone else on these lists... This is, admittedly, a very confusing system for me currently ;-). I saw a post from Justin awhile back concerning CVS and the Manifest file, but this is apparently not the same issue. I've figured out that 201-19 maps to 10.1.3, but what maps to 10.1.4? And how do I figure this out for myself in the future? There is no good map today. The way the rest of us do this involves one of two methods: 1) wait until you see 2-3 comments on the mailing list that agree; and record that 2) boot a vanilla Mac OS X release of the appropriate vintage, take the output of "uname -a", map "xnu-XXXX" to "Apple-XXXX", and use the latter. Regards, Justin -- /~\ The ASCII Justin C. Walker, Curmudgeon-at-Large \ / Ribbon Campaign X Help cure HTML Email / \ _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

OS X <--> Darwin Tag Mappings?
by Jacob Shaw 26 Apr '02

26 Apr '02

Hi, I'd like an RTFM on how Darwin tags (eg. 201-9-1) map to OS X releases. This is, admittedly, a very confusing system for me currently ;-). I saw a post from Justin awhile back concerning CVS and the Manifest file, but this is apparently not the same issue. I've figured out that 201-19 maps to 10.1.3, but what maps to 10.1.4? And how do I figure this out for myself in the future? Thanks in advance, Jacob _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

Re: I'm looking for the source code to the SMB file-system KEXT
by Andrew Pinski 26 Apr '02

26 Apr '02

On Friday, April 26, 2002, at 06:18 , Michael A. Crawford wrote: I didn't see one @ opensouce.apple.com. Does one exists? -Michael Use the cvs. Thanks, Andrew Pinski _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

Re: Looking for specification of HFS and HFS+
by Eugenio Jarosiewicz 25 Apr '02

25 Apr '02

The 2nd link returned from doing a search on developer.apple.com. Otherwise known as the "Monster HFS+ Technote". http://developer.apple.com/technotes/tn/tn1150.html Please don't cross-post unless it's really, rilly necessary (sometimes it's unavoidable, but rarely so [like for me, I don't really want to send to both, but to try and cut this short...] ). Try one list, then the other. Thanks! -ej On Wednesday, April 24, 2002, at 04:03 PM, Michael A. Crawford wrote: Any pointers would be greatly appreciated. -Michael _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

Re: Looking for specification of HFS and HFS+
by Brian Bergstrand 24 Apr '02

24 Apr '02

At 4:03 PM -0700 4/24/02, Michael A. Crawford wrote: Any pointers would be greatly appreciated. -Michael $ cvs co System/xnu $ cd System/xnu/bsd/hfs <read code with favorite editor> This is probably going to be your best bet right now. There may be a formal spec of HFS somewhere on Apple's dev site. Don't know about HFS+. -- Brian Bergstrand <http://www.classicalguitar.net/brian/> PGP Key ID: 0xB6C7B6A2 The difference between genius and stupidity is that genius has its limits. _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

Looking for specification of HFS and HFS+
by Michael A. Crawford 24 Apr '02

24 Apr '02

Any pointers would be greatly appreciated. -Michael _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

Re: [OT?] BSD licensing
by John Clark 24 Apr '02

24 Apr '02

Am Mittwoch den, 24. April 2002, um 09:40, schrieb Adam Atlas: It seems that Darwin is one of the few (the only?) BSD-derived operating system that does not use the BSD License. I downloaded the 4.4BSD-Lite sources (Darwin is based on 4.4BSD-Lite, right?) and it comes with a copy of the BSD License. And the BSD License says that any product derived from it, in source or binary form, must include that license. How did Apple get around that? BSD license is included in all files derived from BSD in Darwin. However, there are other files in Darwin which Apple has produced and do not require any BSD license. I though 4.4BSD-Lite was in the public domain, but I guess I'm wrong. BSD is not 'in the public domain'. The BSD license says, briefly, that the use is unrestricted, provided a notice the product is derived in part from BSD is provided. The unrestricted part is that one need not supply sources, either original BSD source, or derived works to any third party. The GPL, also not 'in the Public Domain', requires that sources be passed on to third parties. However, this need not be 'without compensation', ie one can charge some fee for providing the source, both original or derived sources. The Apple license requires, among other things, that if you produce something derived from Darwin sources, Apple can require that the sources be fed back into Darwin. (Whether Apple wants it is a different story...) Perhaps others know, but I can't think of any court case involving copyright infringement, where the Free Software Foundation has sued an entity for improper handling of the GPL'd material. _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0

Re: [OT?] BSD licensing
by Jacob Shaw 24 Apr '02

24 Apr '02

Hi Adam, There are actually a lot of BSD-derived operating systems that are, in fact, not BSD licensed. The current state of BSD licensing seems to be "here's the source, do with it what you want". Many folks have used BSD-licensed code in closed source products: - Juniper uses FreeBSD as the foundation of their JUNOS for their routers - Apple uses BSD in duuuh :) - Several firewall vendors use *BSD in their internet appliances - Microsoft apparently uses a lot of FreeBSD networking code in Windows 2000 While this may or may not be considered to be "stealing" by GPL advocates (FTR, I like the GPL), for folks who favor the BSD license, it's all a part of life's plan. >From what I have seen in my code browsings the BSD licenses are intact in the appropriate places in the Darwin source code. For a random example, take a look at /usr/include/signal.h. Hope that helps, Jacob On 4/24/02 9:40 AM, "Adam Atlas" <houou(a)mac.com> wrote: > It seems that Darwin is one of the few (the only?) BSD-derived > operating system that does not use the BSD License. I downloaded the > 4.4BSD-Lite sources (Darwin is based on 4.4BSD-Lite, right?) and it > comes with a copy of the BSD License. And the BSD License says that any > product derived from it, in source or binary form, must include that > license. How did Apple get around that? > > I though 4.4BSD-Lite was in the public domain, but I guess I'm wrong. _______________________________________________ darwin-kernel mailing list | darwin-kernel(a)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.

1 0