January 2002 - Darwin-kernel

IOKit objects are they loaded into a contiguous memory segment?
by Shawn Erickson 13 Jan '02

13 Jan '02

I was in the process of doing some driver optimization... I can reduce the amount of kernel memory used and memory copy times iff it is safe to assume IOKit objects are allocated into contiguous physical memory segments. To better explain... I have a firmware driver object that contains a firmware image ( unsigned short code01[] = { ...image..}; ) that a secondary driver we get a pointer to and then download this firmware to my adapter (adapter DMAs the firmware from the physical address I pass it). Currently I have the secondary driver allocate a contiguous memory segment and copy the image into that segment. I would like to avoid this if possible. Is it safe to simply allocate an IOMemoryDescriptor with a pointer to the image and the images length then call getPhysicalSegment to get the start of next segment I want the adapter to download (I have to DMA in chunks smaller then the whole firmware image). I think I know the answer but I keep swapping between working on different OSes (Window NT/2000, Solaris, Mac OS, and Mac OS X) and it becomes hard to keep things straight :{ .... so I thought I better ask to make sure. Thanks! -Shawn

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Re: Panic Feedback
by Justin C. Walker 09 Jan '02

09 Jan '02

On Wednesday, January 9, 2002, at 12:45 AM, David A. Gatwood wrote: On Tue, 8 Jan 2002, Justin C. Walker wrote: On Tuesday, January 8, 2002, at 06:24 PM, Louis Gerbarg wrote: I have this sneaking suspicion that kdp does not work with USB keyboards (only ADB). 'KDP' is independent of keyboards. It's the network protocol. I assume Louis meant kdb and his hand was just on the wrong place on the keyboard. Shift happens. That's cute :-}. There is a USB/ADB issue for working with the debugger: on non-ADB systems, you can't always interrupt the processor with the (I think) CMD-POWER sequence as you could on an ADB system. I'd assumed that was what he meant. I doubt that KDB cares what kind of console is in use. Regards, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | It's not whether you win or lose... | It's whether *I* win or lose. *--------------------------------------*-------------------------------*

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Re: Panic Feedback
by David A. Gatwood 09 Jan '02

09 Jan '02

On Tue, 8 Jan 2002, Justin C. Walker wrote: > On Tuesday, January 8, 2002, at 06:24 PM, Louis Gerbarg wrote: > > > I have this sneaking suspicion that kdp does not work with USB > > keyboards (only ADB). > > 'KDP' is independent of keyboards. It's the network protocol. I assume Louis meant kdb and his hand was just on the wrong place on the keyboard. Shift happens. David --------------------------------------------------------------------- Check out my weekly web comic: http://www.techmagazine.org

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Re: Panic Feedback
by Justin C. Walker 09 Jan '02

09 Jan '02

On Tuesday, January 8, 2002, at 06:24 PM, Louis Gerbarg wrote: I have this sneaking suspicion that kdp does not work with USB keyboards (only ADB). 'KDP' is independent of keyboards. It's the network protocol. Regards, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | If you're not confused, | You're not paying attention *--------------------------------------*-------------------------------*

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Re: Panic Feedback
by Andrew Gallatin 09 Jan '02

09 Jan '02

Justin C. Walker writes: > > If you type 'k', you will (should) end up talking to the Mach debugger, > KDB, which understands the Mach infrastructure, but not the BSD part. > You will (should) interact with it via the console/keyboard (there are > ways to have the system use a serial console, but it's tricky, and I > don't know if it's been checked out recently; and then there's the > matter of the serial interface). > > If 'c', or 'r', doesn't work, you have some other problem. Not sure > what to do in that case. Have you tried the 2-machine setup? Yep.. I must have some other problem. My original goal was to try to avoid the 2-machine setup for space, power & heat reasons, but it looks like I'll need to just give in & ship a second mac home from the office on the west coast. Thanks! Drew

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Re: Panic Feedback
by Louis Gerbarg 09 Jan '02

09 Jan '02

I have this sneaking suspicion that kdp does not work with USB keyboards (only ADB). Louis On Tuesday, January 8, 2002, at 04:37 PM, Justin C. Walker wrote: On Tuesday, January 8, 2002, at 04:09 PM, Andrew Gallatin wrote: Andrew Gallatin writes: Umesh Vaishamapayan writes: Well, if you build and run DEBUG kernel, you get ddb... A clarification: You get Mach kdb [which is similar to FreeBSD ddb] Excellent! That's exactly what I want. Thanks for the tip. Now, to figure out how to get my dual g4 800 to actually boot a different kernel than the default one.. :) I've finally managed to get another g4 (I'm at a different office) to boot a debug kernel. Now, when this machine panics, I see: <stack trace> Waiting for remote debugger connection. Options..... Type ------------ ---- continue.... 'c' reboot...... 'r' enter kdb... 'k' However, I cannot seem to type anything on the "graphics" console. I was logged into the console at the time of the crash in text mode, via entering >console as the username; eg no windowing was running. Do I need to be running with a serial console? Or doing anything else differently? Or is it looking to talk kdb over the network? The 'waiting for debugger' message indicates that, by default, the system is awaiting a connection via the network. For this, you need a second system, running a Darwin version of gdb that knows how t speak 'kdp' (a simple-minded, UDP-based, request/response protocol). If you type 'k', you will (should) end up talking to the Mach debugger, KDB, which understands the Mach infrastructure, but not the BSD part. You will (should) interact with it via the console/keyboard (there are ways to have the system use a serial console, but it's tricky, and I don't know if it's been checked out recently; and then there's the matter of the serial interface). If 'c', or 'r', doesn't work, you have some other problem. Not sure what to do in that case. Have you tried the 2-machine setup? Regards, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | It's not whether you win or lose... | It's whether *I* win or lose. *--------------------------------------*-------------------------------* _______________________________________________ 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: Panic Feedback
by Andrew Gallatin 09 Jan '02

09 Jan '02

Eugenio Jarosiewicz writes: > Yep, it's over the network. I think it might be possible to do it over > serial but since I have 2 macs ethernet works for me (and I've not had > to debug ethernet recently;-) > OK, looks like I'm back to square one then. I'll just take this G4 back to my home office & be done with it. The power company will love me ;) Thanks, Drew

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Re: Panic Feedback
by Justin C. Walker 09 Jan '02

09 Jan '02

On Tuesday, January 8, 2002, at 04:09 PM, Andrew Gallatin wrote: Andrew Gallatin writes: Umesh Vaishamapayan writes: Well, if you build and run DEBUG kernel, you get ddb... A clarification: You get Mach kdb [which is similar to FreeBSD ddb] Excellent! That's exactly what I want. Thanks for the tip. Now, to figure out how to get my dual g4 800 to actually boot a different kernel than the default one.. :) I've finally managed to get another g4 (I'm at a different office) to boot a debug kernel. Now, when this machine panics, I see: <stack trace> Waiting for remote debugger connection. Options..... Type ------------ ---- continue.... 'c' reboot...... 'r' enter kdb... 'k' However, I cannot seem to type anything on the "graphics" console. I was logged into the console at the time of the crash in text mode, via entering >console as the username; eg no windowing was running. Do I need to be running with a serial console? Or doing anything else differently? Or is it looking to talk kdb over the network? The 'waiting for debugger' message indicates that, by default, the system is awaiting a connection via the network. For this, you need a second system, running a Darwin version of gdb that knows how t speak 'kdp' (a simple-minded, UDP-based, request/response protocol). If you type 'k', you will (should) end up talking to the Mach debugger, KDB, which understands the Mach infrastructure, but not the BSD part. You will (should) interact with it via the console/keyboard (there are ways to have the system use a serial console, but it's tricky, and I don't know if it's been checked out recently; and then there's the matter of the serial interface). If 'c', or 'r', doesn't work, you have some other problem. Not sure what to do in that case. Have you tried the 2-machine setup? Regards, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | It's not whether you win or lose... | It's whether *I* win or lose. *--------------------------------------*-------------------------------*

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Re: Panic Feedback
by Eugenio Jarosiewicz 09 Jan '02

09 Jan '02

On Tuesday, January 8, 2002, at 04:09 PM, Andrew Gallatin wrote: I've finally managed to get another g4 (I'm at a different office) to boot a debug kernel. Good to hear! Now, when this machine panics, I see: <stack trace> Waiting for remote debugger connection. Options..... Type ------------ ---- continue.... 'c' reboot...... 'r' enter kdb... 'k' However, I cannot seem to type anything on the "graphics" console. I was logged into the console at the time of the crash in text mode, via entering >console as the username; eg no windowing was running. Do I need to be running with a serial console? Or doing anything else differently? Or is it looking to talk kdb over the network? Yep, it's over the network. I think it might be possible to do it over serial but since I have 2 macs ethernet works for me (and I've not had to debug ethernet recently;-) Some debugging info is in the Developer Documentation, also found @ : http://www.opensource.apple.com/projects/documentation/howto/html/KEXT_Tuto… HelloDebugger.html -ej FWIW, the behaviour is the same (minus kdb) with the 1.4 kernel which ships with OS-X 10.1 BTW, does devfs_remove() work? I don't see any other code using it, and its where my current panic is happening (on the 5th call to it, out of 64 device nodes). Cheers, Drew

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Re: Panic Feedback
by Andrew Gallatin 09 Jan '02

09 Jan '02

Andrew Gallatin writes: > Umesh Vaishamapayan writes: > > > Well, if you build and run DEBUG kernel, you get ddb... > > > > > > > A clarification: > > > > You get Mach kdb [which is similar to FreeBSD ddb] > > Excellent! That's exactly what I want. Thanks for the tip. > > Now, to figure out how to get my dual g4 800 to actually boot > a different kernel than the default one.. :) I've finally managed to get another g4 (I'm at a different office) to boot a debug kernel. Now, when this machine panics, I see: <stack trace> Waiting for remote debugger connection. Options..... Type ------------ ---- continue.... 'c' reboot...... 'r' enter kdb... 'k' However, I cannot seem to type anything on the "graphics" console. I was logged into the console at the time of the crash in text mode, via entering >console as the username; eg no windowing was running. Do I need to be running with a serial console? Or doing anything else differently? Or is it looking to talk kdb over the network? FWIW, the behaviour is the same (minus kdb) with the 1.4 kernel which ships with OS-X 10.1 BTW, does devfs_remove() work? I don't see any other code using it, and its where my current panic is happening (on the 5th call to it, out of 64 device nodes). Cheers, Drew

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