|
Cosmos (operating System)
C# Open Source Managed Operating System (Cosmos) is a toolkit for building GUI and command-line based operating systems, written mostly in the programming language C# and small amounts of a high level assembly language named X#. ''Cosmos'' is a backronym, in that the acronym was chosen before the meaning. It is open-source software released under a BSD license. , Cosmos encompasses an ahead-of-time (AOT) compiler named IL2CPU to translate Common Intermediate Language (CIL) into native instructions. Cosmos compiles user-made programs and associated libraries using IL2CPU to create a bootable native executable that can be run with no support. The resulting output can be booted from a USB flash drive, CD-ROM, over a network via Preboot Execution Environment (PXE), or inside a virtual machine. Recent releases also allow deploying to certain x86 embedded devices over Universal Serial Bus (USB). While C# is the primary language used by developers (both on the backend and by end us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-source Software
Open-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration, meaning any capable user is able to participate online in development, making the number of possible contributors indefinite. The ability to examine the code facilitates public trust in the software. Open-source software development can bring in diverse perspectives beyond those of a single company. A 2008 report by the Standish Group stated that adoption of open-source software models has resulted in savings of about $60 billion per year for consumers. Open source code can be used for studying and allows capable end users to adapt software to their personal needs in a similar way user scripts an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preboot Execution Environment
In computing, the Preboot eXecution Environment, PXE (most often pronounced as ''pixie'', often called PXE Boot/''pixie boot''.) specification describes a standardized client–server environment that boots a software assembly, retrieved from a network, on PXE-enabled clients. On the client side it requires only a PXE-capable network interface controller (NIC), and uses a small set of industry-standard network protocols such as DHCP and TFTP. The concept behind the PXE originated in the early days of protocols like BOOTP/DHCP/TFTP, and it forms part of the Unified Extensible Firmware Interface (UEFI) standard. In modern data centers, PXE is the most frequent choice for operating system booting, installation and deployment. Overview Since the beginning of computer networks, there has been a persistent need for client systems which can boot appropriate software images, with appropriate configuration parameters, both retrieved at boot time from one or more network servers. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bootloader
A bootloader, also spelled as boot loader or called boot manager and bootstrap loader, is a computer program that is responsible for booting a computer. When a computer is turned off, its softwareincluding operating systems, application code, and dataremains stored on non-volatile memory. When the computer is powered on, it typically does not have an operating system or its loader in random-access memory (RAM). The computer first executes a relatively small program stored in read-only memory (ROM, and later EEPROM, NOR flash) along with some needed data, to initialize RAM (especially on x86 systems), to access the nonvolatile device (usually block device, eg NAND flash) or devices from which the operating system programs and data can be loaded into RAM. Some earlier computer systems, upon receiving a boot signal from a human operator or a peripheral device, may load a very small number of fixed instructions into memory at a specific location, initialize at least one CPU, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU GRUB
GNU GRUB (short for GNU GRand Unified Bootloader, commonly referred to as GRUB) is a boot loader package from the GNU Project. GRUB is the reference implementation of the Free Software Foundation's Multiboot Specification, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific Kernel (computer science), kernel configuration available on a particular operating system's partitions. GNU GRUB was developed from a package called the ''Grand Unified Bootloader'' (a play on Grand Unified Theory). It is predominantly used for Unix-like systems. The GNU, GNU operating system uses GNU GRUB as its boot loader, as do most Linux distributions and the Solaris (operating system), Solaris operating system on x86 systems, starting with the Solaris 10 1/06 release. Operation Booting When a computer is turned on, its BIOS finds the primary bootable device (usually the computer's hard disk) and runs the initial Bootstrapping (c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Management
Memory management is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time. Several methods have been devised that increase the effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the size of the virtual address space beyond the available amount of RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have an extensive effect on overall system performance. In some operating systems, e.g. OS/360 and successors, memory is managed by the operating system. In other operating systems, e.g. Unix-like operating sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File System
In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one large body of data with no way to tell where one piece of data stopped and the next began, or where any piece of data was located when it was time to retrieve it. By separating the data into pieces and giving each piece a name, the data are easily isolated and identified. Taking its name from the way a paper-based data management system is named, each group of data is called a "file". The structure and logic rules used to manage the groups of data and their names is called a "file system." There are many kinds of file systems, each with unique structure and logic, properties of speed, flexibility, security, size and more. Some file systems have been designed to be used for specific applications. For example, the ISO 9660 file system is designe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel (operating System)
The kernel is a computer program at the core of a computer's operating system and generally has complete control over everything in the system. It is the portion of the operating system code that is always resident in memory and facilitates interactions between hardware and software components. A full kernel controls all hardware resources (e.g. I/O, memory, cryptography) via device drivers, arbitrates conflicts between processes concerning such resources, and optimizes the utilization of common resources e.g. CPU & cache usage, file systems, and network sockets. On most systems, the kernel is one of the first programs loaded on startup (after the bootloader). It handles the rest of startup as well as memory, peripherals, and input/output (I/O) requests from software, translating them into data-processing instructions for the central processing unit. The critical code of the kernel is usually loaded into a separate area of memory, which is protected from access by application ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft Visual Studio
Visual Studio is an integrated development environment (IDE) from Microsoft. It is used to develop computer programs including websites, web apps, web services and mobile apps. Visual Studio uses Microsoft software development platforms such as Windows API, Windows Forms, Windows Presentation Foundation, Windows Store and Microsoft Silverlight. It can produce both native code and managed code. Visual Studio includes a code editor supporting IntelliSense (the code completion component) as well as code refactoring. The integrated debugger works both as a source-level debugger and a machine-level debugger. Other built-in tools include a code profiler, designer for building GUI applications, web designer, class designer, and database schema designer. It accepts plug-ins that expand the functionality at almost every level—including adding support for source control systems (like Subversion and Git) and adding new toolsets like editors and visual designers for domain-specific la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debugger
A debugger or debugging tool is a computer program used to software testing, test and debugging, debug other programs (the "target" program). The main use of a debugger is to run the target program under controlled conditions that permit the programmer to track its execution and monitor changes in computer resources that may indicate malfunctioning code. Typical debugging facilities include the ability to run or halt the target program at specific points, display the contents of memory, CPU registers or storage devices (such as disk drives), and modify memory or register contents in order to enter selected test data that might be a cause of faulty program execution. The code to be examined might alternatively be running on an ''instruction set simulator'' (ISS), a technique that allows great power in its ability to halt when specific conditions are encountered, but which will typically be somewhat slower than executing the code directly on the appropriate (or the same) processor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source Code
In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source code. The source code is often transformed by an assembler or compiler into binary machine code that can be executed by the computer. The machine code is then available for execution at a later time. Most application software is distributed in a form that includes only executable files. If the source code were included it would be useful to a user, programmer or a system administrator, any of whom might wish to study or modify the program. Alternatively, depending on the technology being used, source code may be interpreted and executed directly. Definitions Richard Stallman's definition, formulated in his 1989 seminal li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstraction Layer
In computing, an abstraction layer or abstraction level is a way of hiding the working details of a subsystem. Examples of software models that use layers of abstraction include the OSI model for network protocols, OpenGL, and other graphics libraries, which allow the separation of concerns to facilitate interoperability and platform independence. Another example is Media Transfer Protocol, which allows shared access and requires no common file system support but restricts user control compared to mass storage with block-level access. In computer science, an abstraction layer is a generalization of a conceptual model or algorithm, away from any specific implementation. These generalizations arise from broad similarities that are best encapsulated by models that express similarities present in various specific implementations. The simplification provided by a good abstraction layer allows for easy reuse by distilling a useful concept or design pattern so that situations, where it m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platform Invocation Services
Platform Invocation Services, commonly referred to as P/Invoke, is a feature of Common Language Infrastructure implementations, like Microsoft's Common Language Runtime, that enables managed code to call native code. Managed code, such as C# or VB.NET, provides native access to classes, methods, and types defined within the libraries that make up the .NET Framework. While the .NET Framework provides an extensive set of functionality, it may lack access to many lower level operating system libraries normally written in unmanaged code or third party libraries also written in unmanaged code. P/Invoke is the technique a programmer can use to access functions in these libraries. Calls to functions within these libraries occur by declaring the signature of the unmanaged function within managed code, which serves as the actual function that can be called like any other managed method. The declaration references the library's file path and defines the function parameters and return i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Bootloader")
