site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:date:message-id:subject :from:to:content-type:content-transfer-encoding; bh=RDgUOBVvFR9F0T3qjEYzrp/fCDywevzd//GF6DslN4A=; b=IsNklOwq6rBf8gAECn+wYwXK9BkU2KdyICGeCnimhAHfYWnmZikeXQN36ua+VO4Pm1 5GL00xNMa17k8MOG1PiVzxB9n12S0CUEZNsdZskiNGa2P9k6eBY4TDPwWplmZe+7AV2x qoodvYMkH3uNhb2yfLI3nl3SsF3Qj4sl3zmYM= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type :content-transfer-encoding; b=eKn0l0V5Q3DQHgiIReqzqCsrnQwplRx3kfMNpW3tEInjqjDnJnPus6H+DpgP3/YyaH cueZ/dNrgHnzI07ubELmxu7tabIRkjQMn3Vs3iiNpvAXdbaS3PQfGAyJWRatGatYUA2O yXHYoo69h4YgdgrJg/CxWItLko9Q+FArXmsqg= Despite reading Amit Singh's book "OS X Internals" and searching the web, I still am missing some details about how the OS X boot process works. Maybe someone here can enlighten me? The gap I am trying to fill is how the basic kexts are loaded and initialized: When the kernel starts, it appears to need a few drivers which are implemented in external kexts. Only later, when all is set up, there's a daemon which dynamically loads other kexts. I like to understand the binding of the former type of drivers. I understand that there's a kextcache, which binds the kernel with a set of kexts and stores it in /System/Library/Caches/com.apple.kernelcaches/ Question 1: What rule specifies which kexts get linked to that kernel? Is it simply the entire Extensions.mkext? Question 2: What if this file does not exist, can the system still boot, and which component is then taking care of finding the kexts (e.g. is it boot.efi or the kernel or what?) Now to the Extensions.mkext. I understand that this gets automatically created from a running OS X in the background whenever it detects changes to the Extensions folder (or at least in most such cases). Question 3: Does this mkext contain _all_ kexts from the Extensions folder then, or does it sort them out somehow (by what rule)? Amit writes that the boot loader (boot.efi) loads the kernel and Extensions.mkext. Is he referring to the prebound kernel cache file here? Provided that file does not exist (question 2), it probably loads the mktext file and kernel (from the root dir) separately. However, due to Amit's book, the boot_args struct does not provide for passing a reference to the mkext file to the kernel. Question 4: How does the mkext, if loaded separately, get linked to the kernel? (i.e. does the boot loader contain a linker that works like the kextcache command?) Question 5: How do these basic kexts get initialized then? Does the boot loader init them before calling the kernel, or does the kernel find them somehow and init them? -- Thomas Tempelmann, http://www.tempel.org/ _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... This email sent to site_archiver@lists.apple.com