November 2008 - Darwin-kernel

Re: choosing kernel on intel?
by Rick Macklem 04 Nov '08

04 Nov '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com On Mon, 3 Nov 2008, Andrew Gallatin wrote: If I build a custom kernel on Intel, how do I choose to boot into it at boot time? Is the only option to copy it to /mach_kernel, and boot from CD (or another partition) and move things around if it doesn't boot? Yea, as far as I could find out, that's the only way. (I'm hoping that someone else has a different answer, but...) I must say I'm glad I converted over to a kext so I don't have to sweat this any more:-) rick _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… I think you can boot the CD and then run a terminal window/shell from the utilities menu (after selecting language), then mount the partition and use it to copy an old mach_kernel back to /mach_kernel if it won't boot, but I haven't actually done that. This email sent to site_archiver(a)lists.apple.com

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Re: choosing kernel on intel?
by Shantonu Sen 03 Nov '08

03 Nov '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com 2) Use the "boot-args" NVRAM variable, with: $ sudo nvram boot-args="debug=0x144 -v Kernel=mach_kernel.test" 3) Use an EFI boot option with bless, with: $ sudo bless --mount / --setBoot --options "Kernel=mach_kernel.test" Shantonu Sen ssen(a)apple.com Sent from my Mac Pro On Nov 3, 2008, at 1:50 PM, Andrew Gallatin wrote: If I build a custom kernel on Intel, how do I choose to boot into it at boot time? Is the only option to copy it to /mach_kernel, and boot from CD (or another partition) and move things around if it doesn't boot? The last time I built a custom kernel was back before intel, in the ppc days. I have vague memories of being able to load different kernels from OpenFirmware. But there is no shell interface like that for EFI. Drew _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/ssen%40apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… You can get an EFI shell from a few places, for instance rEFIt (<http://refit.sourceforge.net >) or tianocore.org. I wouldn't recommend it, but if you go this approach, you can do something like: fs2:/> \System\Library\CoreServices\boot.efi Kernel=mach_kernel.test If you don't use the EFI shell, there are several options, in increasing order of "ease of use": 1) Edit /Library/Preferences/SystemConfiguration/com.apple.Boot.plist and add an entry for: <key>Kernel</key> <string>mach_kernel.test</string> If you want to revert to the original kernel, you would need to edit that file to either remove the entry entirely, or point back at "mach_kernel" If you want to revert to the original kernel, you can zap NVRAM by holding command-option-P-R at boot. This will reset everything, including your boot-args and boot volume preference This ties the "Kernel=" setting to the boot option in EFI. If you want to temporarily boot back to the original kernel, hold down option at boot to go to the Boot Picker, and then proceed to select your boot volume (whatever was highlighted). Since you used the Boot Picker instead of the boot option set by bless, "Kernel=" is not used, and the original kernel is used. If you permanently want to revert to the original kernel, zap NVRAM with command-option-P-R. There are some even more elaborate methods, but those are probably the most common and useful options. This email sent to ssen(a)apple.com This email sent to site_archiver(a)lists.apple.com

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choosing kernel on intel?
by Andrew Gallatin 03 Nov '08

03 Nov '08

site_archiver(a)lists.apple.com Delivered-To: darwin-kernel(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=simple/simple; d=cs.duke.edu; s=mail; t=1225749028; bh=/p3OJGoeZ4gcAK/nxzCNxOY3iVbM9qxLAxNWLSCbvjY=; h=Message-ID:Date:From:MIME-Version:To:Subject:Content-Type: Content-Transfer-Encoding; b=dnu6Vt4moKb6UvdP86XGOdYxM7SA1UAI8URky KbBKIlTJWVsNyavjWExZJRu/uFqU3Zy7x5rjky5MHVC3RL+V/70PuFu0eQiUsr/glFG 18PX8Dwvsu6yDwtc5nzZltlBJcSpYKA0ebL13/tPqtaafAyacZ7NXDxYLdsNc6cnIaE = User-agent: Thunderbird 2.0.0.16 (X11/20080724) If I build a custom kernel on Intel, how do I choose to boot into it at boot time? Is the only option to copy it to /mach_kernel, and boot from CD (or another partition) and move things around if it doesn't boot? The last time I built a custom kernel was back before intel, in the ppc days. I have vague memories of being able to load different kernels from OpenFirmware. But there is no shell interface like that for EFI. Drew _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.… This email sent to site_archiver(a)lists.apple.com

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