.TH rtapi_region "3rtapi" "2006-10-12" "LinuxCNC Documentation" "RTAPI" .SH NAME rtapi_region \- functions to manage I/O memory regions .SH SYNTAX .HP void *rtapi_request_region(unsigned long \fIbase\fR, unsigned long int \fIsize\fR, const char *\fIname\fR) .HP void rtapi_release_region(unsigned long \fIbase\fR, unsigned long int \fIsize\fR) .SH ARGUMENTS .IP \fIbase\fR The base address of the I/O region .IP \fIsize\fR The size of the I/O region .IP \fIname\fR The name to be shown in /proc/ioports .SH DESCRIPTION \fBrtapi_request_region\fR reserves I/O memory starting at \fIbase\fR and going for \fIsize\fR bytes. .SH REALTIME CONSIDERATIONS May be called from realtime init/cleanup code only. .SH BUGS On kernels before 2.4.0, \fBrtapi_request_region\fR always suceeds. .SH RETURN VALUE \fBrtapi_request_region\fR returns NULL if the allocation fails, and a non-NULL value otherwise. \fBrtapi_release_region\fR has no return value.