Abstract: Systems and methods for automated migration of operating systems on computing devices are disclosed. For example, a system may include a processor, and a storage operatively coupled to the processor. The storage stores instructions that perform operations that may include reducing a size of the first operating system to require less space on a first storage portion storing the first operating system, repartitioning the storage to form a second storage portion sized to receive a second operating system, installing a bootloader operable to load either the first operating system or the second operating system, installing the second operating system into the second storage portion, rebooting the system using the bootloader, receiving an input indicative of a selection of either the first operating system or the second operating system, and booting one of the first operating system or the second operating system in accordance with the input.

Abstract: A transaction safe file system uses two sets of file allocation tables and bitmap images to perform file modifications on one of the sets while the other set remains a last known good set. After a modification is complete, a pointer is changed to the newly modified set, and the newly modified set becomes the last known good set. The sets are then synchronized. The file allocation table is used to define cluster chains while the bitmap image is used to determine if a cluster is free or not. In some operations, only the bitmap image may need to be manipulated. The file system may be used in a transaction safe mode as well as a non-transaction safe mode.

Abstract: Directories in a file system are defined with a dummy cluster in a file allocation table as the initial entry. Subsequent clusters in a directory's definition may define any data for the directory that can be changed in a transaction-safe mode. A directory may be modified in a transaction-safe mode by modifying any of the subsequent clusters while tracking changes in a second file allocation table. When the changes have been made to the directory, a pointer to the second file allocation table may be switched to indicate that the second file allocation table is now last known good. The first file allocation table may then be synchronized with the second.

Abstract: Directories in a file system are defined with a dummy cluster in a file allocation table as the initial entry. Subsequent clusters in a directory's definition may define any data for the directory that can be changed in a transaction-safe mode. A directory may be modified in a transaction-safe mode by modifying any of the subsequent clusters while tracking changes in a second file allocation table. When the changes have been made to the directory, a pointer to the second file allocation table may be switched to indicate that the second file allocation table is now last known good. The first file allocation table may then be synchronized with the second.

Abstract: Scheduling of threads in a multi-core system is performed using per-processor queues for each core to hold threads with fixed affinity for each core. Cores are configured to pick the highest priority thread among the global run queue, which holds threads without affinity, and their respective per-processor queue. To select between two threads with same priority on both queues, the threads are assigned sequence numbers based on their time of arrival. The sequence numbers may be weighted for either queue to prioritize one over the other.

Abstract: Directories in a file system are defined with a dummy cluster in a file allocation table as the initial entry. Subsequent clusters in a directory's definition may define any data for the directory that can be changed in a transaction-safe mode. A directory may be modified in a transaction-safe mode by modifying any of the subsequent clusters while tracking changes in a second file allocation table. When the changes have been made to the directory, a pointer to the second file allocation table may be switched to indicate that the second file allocation table is now last known good. The first file allocation table may then be synchronized with the second.

Abstract: Embodiments provide a security infrastructure that may be configured to run on top of an existing operating system to control what resources can be accessed by an applications and what APIs an application can call. Security decisions are made by taking into account both the current thread's identity and the current thread's call chain context to enable minimal privilege by default. The current thread context is captured and a copy of it is created to be used to perform security checks asynchronously. Every thread in the system has an associated identity. To obtain access to a particular resource, all the callers on the current thread are analyzed to make sure that each caller and thread has access to that resource. Only when each caller and thread has access to that resource is the caller given access to that resource.

Abstract: Scheduling of threads in a multi-core system running various legacy applications along with multi-core compatible applications is configured such that threads from older single thread applications are assigned fixed affinity. Threads from multi-thread/single core applications are scheduled such that one thread at a time is made available to the cores based on the thread priority preventing conflicts and increasing resource efficiency. Threads from multi-core compatible applications are handled regularly.

Abstract: Directories in a file system are defined with a dummy cluster in a file allocation table as the initial entry. Subsequent clusters in a directory's definition may define any data for the directory that can be changed in a transaction-safe mode. A directory may be modified in a transaction-safe mode by modifying any of the subsequent clusters while tracking changes in a second file allocation table. When the changes have been made to the directory, a pointer to the second file allocation table may be switched to indicate that the second file allocation table is now last known good. The first file allocation table may then be synchronized with the second.

Abstract: A transaction safe file system uses two sets of file allocation tables and bitmap images to perform file modifications on one of the sets while the other set remains a last known good set. After a modification is complete, a pointer is changed to the newly modified set, and the newly modified set becomes the last known good set. The sets are then synchronized. The file allocation table is used to define cluster chains while the bitmap image is used to determine if a cluster is free or not. In some operations, only the bitmap image may need to be manipulated. The file system may be used in a transaction safe mode as well as a non-transaction safe mode.

Abstract: Directories in a file system are defined with a dummy cluster in a file allocation table as the initial entry. Subsequent clusters in a directory's definition may define any data for the directory that can be changed in a transaction-safe mode. A directory may be modified in a transaction-safe mode by modifying any of the subsequent clusters while tracking changes in a second file allocation table. When the changes have been made to the directory, a pointer to the second file allocation table may be switched to indicate that the second file allocation table is now last known good. The first file allocation table may then be synchronized with the second.

Abstract: A transaction safe file system uses two sets of file allocation tables and bitmap images to perform file modifications on one of the sets while the other set remains a last known good set. After a modification is complete, a pointer is changed to the newly modified set, and the newly modified set becomes the last known good set. The sets are then synchronized. The file allocation table is used to define cluster chains while the bitmap image is used to determine if a cluster is free or not. In some operations, only the bitmap image may need to be manipulated. The file system may be used in a transaction safe mode as well as a non-transaction safe mode.

Abstract: This disclosure describes techniques of using a centralized rule database to control the abilities of software processes to perform actions with regard to resources provided by a computer. As described herein, each software process executing in a computer executes within a chamber and each resource provided by the computer is associated with a canonical name that uniquely identifies the resource. Furthermore, the computer stores a set of security rules in a centralized rule database. In addition, this disclosure describes techniques of enforcing the rules stored in the centralized rule database.

Abstract: A transaction safe file system uses two sets of file allocation tables and bitmap images to perform file modifications on one of the sets while the other set remains a last known good set. After a modification is complete, a pointer is changed to the newly modified set, and the newly modified set becomes the last known good set. The sets are then synchronized. The file allocation table is used to define cluster chains while the bitmap image is used to determine if a cluster is free or not. In some operations, only the bitmap image may need to be manipulated. The file system may be used in a transaction safe mode as well as a non-transaction safe mode.

Abstract: A transaction safe file system uses two sets of file allocation tables and bitmap images to perform file modifications on one of the sets while the other set remains a last known good set. After a modification is complete, a pointer is changed to the newly modified set, and the newly modified set becomes the last known good set. The sets are then synchronized. The file allocation table is used to define cluster chains while the bitmap image is used to determine if a cluster is free or not. In some operations, only the bitmap image may need to be manipulated. The file system may be used in a transaction safe mode as well as a non-transaction safe mode.

Abstract: Directories in a file system are defined with a dummy cluster in a file allocation table as the initial entry. Subsequent clusters in a directory's definition may define any data for the directory that can be changed in a transaction-safe mode. A directory may be modified in a transaction-safe mode by modifying any of the subsequent clusters while tracking changes in a second file allocation table. When the changes have been made to the directory, a pointer to the second file allocation table may be switched to indicate that the second file allocation table is now last known good. The first file allocation table may then be synchronized with the second.

Abstract: Embodiments provide a security infrastructure that may be configured to run on top of an existing operating system to control what resources can be accessed by an applications and what APIs an application can call. Security decisions are made by taking into account both the current thread's identity and the current thread's call chain context to enable minimal privilege by default. The current thread context is captured and a copy of it is created to be used to perform security checks asynchronously. Every thread in the system has an associated identity. To obtain access to a particular resource, all the callers on the current thread are analyzed to make sure that each caller and thread has access to that resource. Only when each caller and thread has access to that resource is the caller given access to that resource.

Abstract: Directories in a file system are defined with a dummy cluster in a file allocation table as the initial entry. Subsequent clusters in a directory's definition may define any data for the directory that can be changed in a transaction-safe mode. A directory may be modified in a transaction-safe mode by modifying any of the subsequent clusters while tracking changes in a second file allocation table. When the changes have been made to the directory, a pointer to the second file allocation table may be switched to indicate that the second file allocation table is now last known good. The first file allocation table may then be synchronized with the second.

Abstract: This disclosure describes techniques of using a centralized rule database to control the abilities of software processes to perform actions with regard to resources provided by a computer. As described herein, each software process executing in a computer executes within a chamber and each resource provided by the computer is associated with a canonical name that uniquely identifies the resource. Furthermore, the computer stores a set of security rules in a centralized rule database. In addition, this disclosure describes techniques of enforcing the rules stored in the centralized rule database.

Abstract: The present invention provides an efficient application oriented security model. Prior to execution, an application is authenticated, and security information associated with the application is retrieved. The security information is then used to generate a token that is attached to the application. The security information may include a principle account associated with the application, a list of group accounts, and a corresponding privilege list.