Operating System Context Switching

Abstract

A technique for quickly switching between a first operating system (OS) and a second OS involves deactivating the first OS and booting the second OS from memory. The technique can include inserting a context switching layer between the first OS and a hardware layer to facilitate context switching. It may be desirable to allocate memory for the second OS and preserve state of the first OS before deactivating the first OS and booting the second OS from memory.

1 . A system comprising:
 a context switching layer insertion engine;   an operating system (OS) memory allocation engine coupled to the context switching layer insertion engine;   a memory boot engine including a processor, the memory boot engine coupled to the context switching layer insertion engine;   wherein, in operation:
 the context switching layer insertion engine inserts a context switching layer between a first OS and a hardware layer; 
 the OS memory allocation engine allocates memory for a second OS and loads data associated with the second OS into the memory; 
 the memory boot engine boots the second OS from memory. 
   
     
     
         2 . The system of  claim 1 , wherein the context switching layer comprises a minimalist hypervisor. 
     
     
         3 . The system of  claim 1 , wherein inserting the context switching layer comprises intercepting a control signal from the first OS or the second OS, and the hardware layer. 
     
     
         4 . The system of  claim 1 , wherein inserting the context switching layer comprises:
 receiving, at the context switching layer insertion engine, a first signal from the first OS or the second OS;   providing, from the context switching layer insertion engine, a second signal to the hardware layer, the second signal appearing to the hardware layer as if the second signal were coming from the first OS or the second OS.   
     
     
         5 . The system of  claim 4 , wherein the first signal comprises a request for hardware resources from the hardware layer. 
     
     
         6 . The system of  claim 1 , wherein inserting the context switching layer comprises:
 receiving an indication from the first OS that the first OS is to go to sleep;   intercepting a write request from the first OS to the hardware layer;   setting, in the hardware layer, a sleep type or sleep enable bits associated with the first OS.   
     
     
         7 . The system of  claim 6 , wherein the write request comprises one or more requests to a power management block of the hardware layer. 
     
     
         8 . The system of  claim 1 , wherein the context switching layer comprises an input/output (I/O) driver configured to enable saving a state of the first OS to a datastore. 
     
     
         9 . The system of  claim 1 , wherein, in operation:
 the context switching layer insertion engine inserts another context switching layer between the second OS and the hardware layer;   the OS memory allocation engine allocates another memory for the first OS and loads data associated with the first OS into the other memory;   the memory boot engine boots the first OS from the other memory, thereby restoring the first OS.   
     
     
         10 . A method comprising:
 inserting a context switching layer between a first OS and a hardware layer;   allocating memory for a second OS;   loading data associated with the second OS into the memory;   booting the second OS from memory.   
     
     
         11 . The method of  claim 10 , wherein the context switching layer comprises a minimalist hypervisor. 
     
     
         12 . The method of  claim 10 , wherein inserting the context switching layer comprises intercepting a control signal from the first OS or the second OS, and the hardware layer. 
     
     
         13 . The method of  claim 10 , wherein inserting the context switching layer comprises:
 receiving, at the context switching layer insertion engine, a first signal from the first OS or the second OS;   providing, from the context switching layer insertion engine, a second signal to the hardware layer, the second signal appearing to the hardware layer as if the second signal were coming from the first OS or the second OS.   
     
     
         14 . The method of  claim 13 , wherein the first signal comprises a request for hardware resources from the hardware layer. 
     
     
         15 . The method of  claim 10 , wherein inserting the context switching layer comprises:
 receiving an indication from the first OS that the first OS is to go to sleep;   intercepting a write request from the first OS to the hardware layer;   setting, in the hardware layer, a sleep type or sleep enable bits associated with the first OS.   
     
     
         16 . The method of  claim 15 , wherein the write request comprises one or more requests to a power management block of the hardware layer. 
     
     
         17 . The method of  claim 10 , wherein the context switching layer comprises an input/output (I/O) driver configured to enable saving a state of the first OS to a datastore. 
     
     
         18 . The method of  claim 10 , further comprising:
 inserting another context switching layer between the second OS and the hardware layer;   allocating another memory for the first OS and loads data associated with the first OS into the other memory;   booting the first OS from the other memory, thereby restoring the first OS.   
     
     
         19 . A system comprising:
 at least one processor;   memory storing instructions configured to instruct the at least one processor to perform:
 inserting a context switching layer between a first OS and a hardware layer; 
 allocating a portion of the memory for a second OS; 
 loading data associated with the second OS into the portion of the memory; 
 booting the second OS from the portion of the memory. 
   
     
     
         20 . The system of  claim 19 , wherein the context switching layer comprises a minimalist hypervisor.