RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating system designed for embedded systems.
The acronym RTEMS initially stood for Real-Time Executive for Missile Systems, then became Real-Time Executive for Military Systems before changing to its current meaning. RTEMS development began in the late 1980s with early versions of RTEMS available via ftp as early as 1993. OAR Corporation is currently managing the RTEMS project in cooperation with a Steering Committee which includes user representatives.
Program to simulate Rayleigh fading using a p-th order autoregressive model AR(p) according to
％ Baddour s work: "Autoregressive modeling for fading channel simulation"
1、 了解系統調用fork()、execl()、exit()、getpid()和waitpid()的功能和實現過程
2、 編寫一段程序實現以下功能：
a) 使用系統調用fork()創建兩個子進程
b) 父進程重復顯示字符串”parent:”，并使用函數getpid()顯示自己的進程ID。
c) 兩個子進程分別重復顯示字符串”child:”，并使用函數getpid()顯示自己的進程ID
3、 編寫一段程序實現以下功能：
a) 使用系統調用fork()創建一個子進程
b) 子進程顯示自己的進程ID和字符串": The child is calling an exec.\n"，然后通過execl()調用系統命令ps顯示當前運行的進程情況，從而更換自己的執行代碼，最后調用exit()結束。
c) 父進程顯示自己的進程ID和字符串” ": The parent is waiting for child to exit.\n "，然后調用waitpid()等待子進程結束，并在子進程結束后顯示”The parent exit.\n
