The Windows CE New Kernel.ppt

Windows CE 6.0 Architecture Douglas Boling President Boling Consulting Inc. Speaker Douglas Boling dbolingmedc @ Author – “Programming Microsoft Windows CE 3rd Edition” Trainer – Classes on Windows CE App Development Windows CE OAL Development .NET Compact Framework Consultant – Work with companies to help their Windows CE application and platform development efforts Agenda Overview - Introduction Windows CE 6 Memory Model New Features Compatibility BSP Changes Brief HistoryWhat we’ve been doing Windows CE Limits From Windows CE 1 to Windows CE 5, Windows CE has always had limits 32 processes at any one time 32 MB Virtual Memory per process Windows CE 5.0 Memory Model Windows CE 5.0 Memory Model Virtual Memory Map 2 GB for Kernel Single 2 GB mapping for all processes Divided up into 32 MB “slots” 32 Process Limit Each process has one 32 MB slot 32 slots for processes Shared memory Upper half of user space is shared memory Read / Write by all processes Windows CE 6.0 Memory Model Windows CE Memory Model Introducing the New Kernel 2 GB of Virtual Memory per process 32,000 processes Unified Kernel Critical OS components moved into kernel space Improved system performance Increased security and robustness High degree of backwards compatibility Application Virtual Memory Space Kernel Virtual Memory Space New OS Layout Moving critical drivers, file system, and graphical window manager into the kernel Kernel version of Coredll.dll Same APIs without the thunks Benefit Greatly reduces the overhead of system calls between these components Reduces overhead of all calls from user space to kernel space Increase code sharing between base OS services New OS Layout Performance Size Improvements expected in process switching Same performance Thread Switching Memory Allocation System Calls Some slow down with interprocess calls Now involves data marshalling Size increase is less then 5% Windows CE 5.0 System Calls Application makes