April 2004 - Darwin-kernel - lists.apple.com

Re: system call
by Dean Reece 15 Apr '04

15 Apr '04

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(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.

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system call
by yetty 15 Apr '04

15 Apr '04

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(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.

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Re: Directories appearing as volume aliases in 10.3 Finder
by Sam Vaughan 15 Apr '04

15 Apr '04

Implementing vop_getattrlist() seems to be helping. At the moment I'm not doing much that's useful in there, but it's enough to force Open/Save dialogs to do lstats and trust them. Next I'll return stat information from vop_getattrlist() to remove the need for all the lstats. After that I'll implement vop_readdirattr() to return everything in one hit. Hopefully after that the sluggishness in the Open/Save dialog will be history. I get the impression that 10.3 wasn't tested very well/at all on file systems that didn't support vop_getattrlist(). Of course we could have helped out there, but we weren't in a position to port to Panther until recently! Sam _______________________________________________ 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.

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Re: Directories appearing as volume aliases in 10.3 Finder
by Quinn 14 Apr '04

14 Apr '04

At 9:45 +1000 14/4/04, Sam Vaughan wrote: Is there another area of the VOP interface I should be focussing on to find the source of this behaviour? vop_getattrlist perhaps, which we still haven't implemented? Do I need to look into volfs? Well, supporting volfs will probably perturb your code sufficiently that this particular problem will go away, but it's a lot of work and it's hard to justify without knowing exactly why things aren't working. Non volfs network file systems should work. You can try your tests on SMB and NFS to verify this. The fact that the "open" command in Terminal fails with nsvErr makes it seems like your volume isn't known to the Carbon File Manager. This is a nice test case because the code for "open" is tiny. I'd definitely try to push hard on this to see what's going wrong. There are a number of things you can try. o Divide and conquer -- "open" is implemented using AppKit. It launches applications using -[NSWorkspace launchApplication:...] and documents with -[NSWorkspace openFile:...], at which point NSWorkspace passes the request to Launch Services (LSOpenFromURLSpec). My guess is that the error is coming from Launch Services, not from "open" itself or NSWorkspace. You could check this by setting breakpoints on the NSWorkspace and LS routines to see whether they're ever called. Naturally you'll have to do this in a working example as well, just to make sure that things work the way you (and indeed I) expect (-: o fs_usage -- To get a high-level overview of what BSD calls "open" makes, run it under fs_usage. Again, it would be worthwhile to do this for both a working and non-working example. o _debug -- You can easily run "open" using the _debug libraries. This might cause them to spit out a useful error. guy-smiley:QuinnXHome quinn$ gdb /usr/bin/open GNU gdb 5.3-20030128 [...] (gdb) set env DYLD_IMAGE_SUFFIX _debug (gdb) r /Applications/TextEdit.app For problems like this I generally recommend that the developer file open a DTS tech support incident so that I can look into it in more detail. <http://developer.apple.com/technicalsupport/index.html> S+E -- Quinn "The Eskimo!" <http://www.apple.com/developer/> Apple Developer Technical Support * Networking, Communications, Hardware _______________________________________________ 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.

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Re: urgent question
by Dean Reece 14 Apr '04

14 Apr '04

Most likely a permissions problem, but it is impossible to tell given the information you have provided. You should run (as root) the command "kextload -t -n kerneltest001.kext" & "kextload -t -n HelloIOKit.kext" and examine the resulting messages. If they say something about "Kext not authentic", you should make sure their permissions are read-only and ownership is root:wheel. You can use the commands: chown -R root:wheel kerneltest001.kext HelloIOKit.kext chmod -R go-w kerneltest001.kext HelloIOKit.kext to fix up the permissions. This is documented at http://developer.apple.com/documentation/ReleaseNotes/Darwin/ KernelExtensions.html There may be other problems, but this is the most common. Cheers, - Dean On Apr 13, 2004, at 11:21 PM, yetty wrote: Dear Sir/Madam, I am trying kernel programming on Mac OS X. I have read the following 3 papers: Kernel Extension Dependencies Creating a DeviceDriver With Project Builder Packaging Your KEXT for Distribution and Installation And I have write two kernel programs. One is accroding to Kernel Extension Dependencies and I name the project as kerneltest001. The other is accroding to Creating a DeviceDriver With Project Builder and I name the project HelloIOKit. After I have finished packaging and installing the projects,I can find them on window of "system.profile->Extensions". On the top of this window there are four column. On the first column there many .kext files such as ACard62xxM.kext,ACard671xSCSI.kext .My project kerneltest001.kext and HelloIOKit.kext are also there. But on the fourth column says that my kerneltest001.kext and HelloIOKit.kext are "You can not use", why? yours sincerely user of Mac _______________________________________________ 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.

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urgent question
by yetty 14 Apr '04

14 Apr '04

Dear Sir/Madam, I am trying kernel programming on Mac OS X. I have read the following 3 papers: Kernel Extension Dependencies Creating a DeviceDriver With Project Builder Packaging Your KEXT for Distribution and Installation And I have write two kernel programs. One is accroding to Kernel Extension Dependencies and I name the project as kerneltest001. The other is accroding to Creating a DeviceDriver With Project Builder and I name the project HelloIOKit. After I have finished packaging and installing the projects,I can find them on window of "system.profile->Extensions". On the top of this window there are four column. On the first column there many .kext files such as ACard62xxM.kext,ACard671xSCSI.kext .My project kerneltest001.kext and HelloIOKit.kext are also there. But on the fourth column says that my kerneltest001.kext and HelloIOKit.kext are "You can not use", why? yours sincerely user of Mac _______________________________________________ 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.

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Re: Directories appearing as volume aliases in 10.3 Finder
by Sam Vaughan 13 Apr '04

13 Apr '04

Thanks for the debugging information Quinn, here's what I've found so far: I added some code to allow me to return the correct type information in the dirents and it fixed the icons in the Finder. It's a huge performance hit on large directories so I'd love to see the regression addressed in 10.4 if possible. I reported the issue as Radar bug #3620414. Although I'm now returning type information in the dirent structures, I'm still seeing some strange behaviour when working with files that aren't in the root directory. If I create a directory and copy a movie into it, it appears in the Finder as expected. In column view, the Finder can even bring up a preview of the movie correctly. If I double click the movie though, QuickTime Player opens but the movie doesn't. Using the Open dialog is very tedious with lots of beach ball time. When it finally decides what icons to use, I get aliases to network volumes again! I tried deleting all the persistent storage I could think of: /Desktop\ DB, /Desktop\ DF and any .DSStore files in the vicinity. I haven't rebuilt the file system yet but I'll try that next. Using PrintVolumeInfo/PrintFileIDTree I don't get any files, just the root vnode: 2 "stripe4k" (02) Using the "open" command with the file's full path from the Terminal fails with a -35 nsvErr (no such volume). The thing that concerns me the most is that it's not deterministic. I recently saw proper folder icons in the open dialog and managed to open and play the movie file (although using the dialog was still very slow). I also once saw full PrintFileIDTree output with the correct type codes and directory hierarchy. Is there another area of the VOP interface I should be focussing on to find the source of this behaviour? vop_getattrlist perhaps, which we still haven't implemented? Do I need to look into volfs? Sam _______________________________________________ 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.

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RE: Creating a mountable pseudo device
by Brad Post (MACBU) 08 Apr '04

08 Apr '04

Why not just use Apple's Disk Image Plugin API? You can have the data in any format as long as you are passing back the correct information? -----Original Message----- From: darwin-kernel-admin(a)lists.apple.com [mailto:darwin-kernel-admin@lists.apple.com] On Behalf Of Tim Hewett Sent: Monday, April 05, 2004 4:03 AM To: darwin-kernel(a)lists.apple.com Subject: Creating a mountable pseudo device Hello, I am trying to find out how to create a device which can be mounted and ejected in the same kind of way as a disk image. I.e. a disk image isn't a real physical device as such, but it can be mounted and presumably there is a process which acts as a translator between the contents of the disk image and the kernel's wish to reference it as a filesystem. I would like to do something very similar but cannot find any documentation describing an API or any examples demonstrating this. Any suggestions on where to find this info would be much appreciated. Also would it be necessary to write this, or part of it, in kernel space, or is it possible to do it entirely in user space? Regards, Tim. _______________________________________________ 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. _______________________________________________ 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.

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Re: any info on next-gen firewall (ipfw2)?
by Sam Hart 07 Apr '04

07 Apr '04

josh wrote: We are aware that the firewall is falling behind. We are looking at ipfw2. richard wrote: great to hear! it'll make gateway migration to OSX from *BSD (e.g.) a bit less painful ... can you comment re: whether as built-in the kernel, or as an extension? the former (maybe?) probably has some performance advantages, but the latter could allow for the inclusion/addition of "pf" as well. i've read strong arguments on the lists for both pkgs ... It will most likely be an network kernel extension, best to do it the Darwin way ;) I currently use pf and have nothing but positive things to say about it. S a m ------------------------------------------------------------------------ ------ Drawing on my fine command of language, I said nothing. _______________________________________________ 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.

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Re: Directories appearing as volume aliases in 10.3 Finder
by Quinn 07 Apr '04

07 Apr '04

At 15:50 +1000 7/4/04, Sam Vaughan wrote: Any ideas on workarounds for this would be terrific! Some thoughts... All of this stuff lives at the Carbon File Manager level, not the Finder. My guess is that any other Carbon client would have exactly the same problem. It would be worthwhile testing that guess by writing a simple Carbon tool that calls FSGetCatalogInfo and prints the results. This has a number of advantages. First, it lets you determine exactly what the problem is at the Carbon File Manager level. Second, you can do intensive debugging on your test program that would be inappropriate on the Finder. Looking at the code it seems that the Carbon File Manager is supposed to handle DT_UNKNOWN. If the type is unknown it's supposed to call lstat on the file and set the type based on that. The mechanism used by Carbon File Manager to emulate Carbon file system semantics on top of Posix volumes is quite complex. I don't really understand it too well myself yet. However, there are some interesting debugging facilities built in to Carbon File Manager. If you run GDB and attach to the Finder, you call call three routines to dump out Carbon File Manager state. (gdb) call (void)PrintVolumeInfo(0) This prints the volume list. The output will show up in Console. (gbb) call (void)PrintFileIDTree(-114) This prints the "file ID tree" for a specific volume (substitute the vRefNum for "-114" in the above command line). The file ID tree only exists for Posix volumes. It allows Carbon File Manager to implement "access by file ID" semantics on volumes that don't support it (that is, Posix volumes, that is, volumes that don't support volfs). The output will look something like this: 2 "UFS Victim" (02) . 27 "CStarter.c" (01) . 25 "Proto-Answer" (01) . 18 ".Trashes" (02) . . 22 "501" (02) The first number is the Carbon file ID for the node. The string in quotes is the node name. The number in brackets is the node type (0 = unknown, 1 = file, 2 = directory, 3 = link). The dots indicate directory nesting. (gdb) call (void)PrintEnumerationCache(-114) This prints Carbon File Manager's directory enumeration cache. I'm not sure how you can use this information for this specific problem, but I'm sure you'll find it useful. S+E -- Quinn "The Eskimo!" <http://www.apple.com/developer/> Apple Developer Technical Support * Networking, Communications, Hardware _______________________________________________ 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.

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