Where is mach kernel

It is the heart of the operating system, known as the 'kernel'. There are a lot of other files at the root of your file system, that are essential to the normal operation of Mac OS X. You should not mess with them, unless you really know what you are doing, and then it would be wise to have 1 or several backups, as messing with operating system files can easily result in disabling the system, requiring a restore from backup.

Page content loaded. Apr 12, PM. It's a bit out of date in that it covers William Lloyd, Where would be a good place to ask questions like that? But my concern is why is this not the place to ask questions such as the one above? As this is my first time being within the community, this inquiring mind wants to know. I am afraid technology got ahead of me. So I am looking for some good training tools.

But since I now have to pay to have someone to work on my Mini, I need to know where to ask questions here in the community as I can not afford the repair bills. Is there a bibliography somewhere here that us newbies can refer to? The only books I am familiar with are the ones by Randy Singer. Besides Singh's book, are there others you would recommend. I just joined the community in hopes someone would have an answer for my current problem, but now I am not sure where to post the question and am afraid of being yelled at for posting in the wrong place.

The only change I made was switching from Pandora to Spotify. I am not currently using any Adobe products except Reader. I am having to restart the computer almost every 2 hours.

Apr 13, PM. Apr 14, AM in response to wilssearch In response to wilssearch. It's great for those making the 'switch' from Windows to the most current OS. Apr 14, AM. I think William was referring specifically to the several very general questions OSXbit has posted recently. It's kind of like someone who wants to learn how an engine works posting a series of questions about what its parts are.

For things like that a Google search or a book are much better learning aids. These forums are much better suited to specific questions that users can answer from their own shared experience, the kind of things that would be difficult to find in a book or a search of Apple's support site, etc.

It is always a good idea to start with these more comprehensive sources if you can -- in fact, some will lead to topics in these forums that have already been answered quite well, saving you a lot of time. Of course, it is difficult to do that if your question can't be condensed into a good search term or you get thousands of unrelated hits from your search.

Ports are often used to grant clients access to objects within Mach. As such, port right ownership is the fundamental security mechanism within Mach. Having a right to an object is to have a capability to access or manipulate that object.

Port rights can be copied and moved between tasks via IPC. Doing so, in effect, passes capabilities to some object or server. One type of object referred to by a port is a port set. As the name suggests, a port set is a set of port rights that can be treated as a single unit when receiving a message or event from any of the members of the set. Port sets permit one thread to wait on a number of message and event sources, for example in work loops.

Traditionally in Mach, the communication channel denoted by a port was always a queue of messages. However, OS X supports additional types of communication channels, and these new types of IPC object are also represented by ports and port rights. Ports and port rights do not have systemwide names that allow arbitrary ports or rights to be manipulated directly.

Ports can be manipulated by a task only if the task has a port right in its port namespace. A port right is specified by a port name , an integer index into a bit port namespace. Each task has associated with it a single port namespace. As with most modern operating systems, Mach provides addressing to large, sparse, virtual address spaces.

Runtime access is made via virtual addresses that may not correspond to locations in physical memory at the initial time of the attempted access. Mach is responsible for taking a requested virtual address and assigning it a corresponding location in physical memory. It does so through demand paging. A range of a virtual address space is populated with data when a memory object is mapped into that range.

All data in an address space is ultimately provided through memory objects. Mach asks the owner of a memory object a pager for the contents of a page when establishing it in physical memory and returns the possibly modified data to the pager before reclaiming the page.

OS X includes two built-in pagers—the default pager and the vnode pager. The default pager handles nonpersistent memory, known as anonymous memory. Anonymous memory is zero-initialized, and it exists only during the life of a task.

The vnode pager maps files into memory objects. Mach exports an interface to memory objects to allow their contents to be contributed by user-mode tasks. The memory management subsystem exports virtual memory handles known as named entries or named memory entries. Like most kernel resources, these are denoted by ports. Having a named memory entry handle allows the owner to map the underlying virtual memory object or to pass the right to map the underlying object to others.

Mapping a named entry in two different tasks results in a shared memory window between the two tasks, thus providing a flexible method for establishing shared memory. Beginning in OS X v In traditional EMMI, two Mach ports were created for each memory region, and likewise two ports for each cached vnode. Portless EMMI, in its initial implementation, replaces this with direct memory references basically pointers.

In a future release, ports will be used for communication with pagers outside the kernel, while using direct references for communication with pagers that reside in kernel space.

The net result of these changes is that early versions of portless EMMI do not support pagers running outside of kernel space. This support is expected to be reinstated in a future release. The underlying virtual memory object is anonymous and backed by the default pager. Shared ranges of an address space may also be set up via inheritance.

When new tasks are created, they are cloned from a parent. This cloning pertains to the underlying memory address space as well. Mapped portions of objects may be inherited as a copy, or as shared, or not at all, based on attributes associated with the mappings.

Mach practices a form of delayed copy known as copy-on-write to optimize the performance of inherited copies on task creation. Rather than directly copying the range, a copy-on-write optimization is accomplished by protected sharing. The two tasks share the memory to be copied, but with read-only access.

When either task attempts to modify a portion of the range, that portion is copied at that time. This lazy evaluation of memory copies is an important optimization that permits simplifications in several areas, notably the messaging APIs. One other form of sharing is provided by Mach, through the export of named regions.

A named region is a form of a named entry, but instead of being backed by a virtual memory object, it is backed by a virtual map fragment. This fragment may hold mappings to numerous virtual memory objects. It is mappable into other virtual maps, providing a way of inheriting not only a group of virtual memory objects but also their existing mapping relationships. This feature offers significant optimization in task setup, for example when sharing a complex region of the address space used for shared libraries.

Communication between tasks is an important element of the Mach philosophy. The endpoints of these communication channels in Mach are called ports, while port rights denote permission to use the channel. The forms of IPC provided by Mach include.

The type of IPC object denoted by the port determines the operations permissible on that port, and how and whether data transfer occurs. I also mounted BaseSystem. Thanks in advance. Mavericks to El Capitan. Hello, I had Mavericks hackintosh with Chimera. I made the bootable usb with El Capitan using Unibeast. I noticed after that I had to download Clover and erase Chimera before updating. After the installation, it restarted and booted the USB to the clover boot loader.

However, it wasn't able I've searched all over the net and tried numerous fixes for this, but nothing worked, sadly. Is this possible? If I choose the legacy installer I get through the first wave of Installation I am able to boot my Yosemite partition with Unibeast, but I am trying to boot from the hard drive itself. Is it possible this could be from the absence of Chameleon 2.