.if n .pH portguide.DISP @(#)DISP	40.3
.\" Copyright 1989 AT&T
.BK "Programmer's Guide: Porting the Kernel"
.CH "Directory - DISP" 10
.H 2 "Directory - DISP"
.IX DISP directory
The following are the notes for the \f3disp\f1 directory, which contains the
code for process scheduling.
.P
.BL
.LI
\f3disp.c  -  MD\f1
.br
.BL
.LI
\f4pswtch  -  MD\f1
.br
\f4pswtch\fP selects a process to run and, if different from current
process, performs part of the context switch to the new process. 
In the porting base code, this involves saving the floating point registers of the
current process, and then loading the MMU registers for sections 2
and 3 (user sections), and finally loading the floating point registers
for the new process.
.br
.sp
The remainder of the context switch takes place elsewhere (see \f4swtch\f1 and
\f4ps_swtch\f1 in the \f3ml\f1 directory).
.LE
.LI
\f3priocntl.c  -  NCR\f1
.br
This is a code for \f4priocntl\f1 and \f4nice\f1 system calls.
.LI
\f3rt.c  -  NCR\f1
.br
This is a class-specific code for real-time scheduling.
.LI
\f3sysclass.c  -  NCR\f1
.br
This is a class-specific code for system class.
.LI
\f3ts.c  -  NCR\f1
.br
This has a class-specific code for time-sharing scheduling class.
.LE

