---
name: "rtapi_region"
section: "3rtapi"
platform: "linux"
package: "linuxcnc-uspace-dev"
version: "1:2.9.4-2+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/rtapi_region"
---

# rtapi\_region(3rtapi)

functions to manage I/O memory regions

## NAME

rtapi\_region - functions to manage I/O memory regions

## SYNTAX

 void \*rtapi\_request\_region(unsigned long *base*, unsigned long int *size*, const char \**name*)

 void rtapi\_release\_region(unsigned long *base*, unsigned long int *size*)

## ARGUMENTS

- *base*

  The base address of the I/O region

- *size*

  The size of the I/O region

- *name*

  The name to be shown in /proc/ioports

## DESCRIPTION

**rtapi\_request\_region** reserves I/O memory starting at *base* and going for *size* bytes.

## REALTIME CONSIDERATIONS

May be called from realtime init/cleanup code only.

## RETURN VALUE

**rtapi\_request\_region** returns NULL if the allocation fails, and a non-NULL value otherwise.

**rtapi\_release\_region** has no return value.