I/O Options

The ChorusOS operating system provides the following optional I/O services:

FS_MAPPER

The FS_MAPPER feature provides support for swap in the IOM. It requires SCSI_DISK to be configured, as well as VIRTUAL_ADDRESS_SPACE and ON_DEMAND_PAGING.

The FS_MAPPER feature exports the swapon() system call.

For details, see the FS_MAPPER(5FEA) man page.

DEV_CDROM

The DEV_CDROM feature provides an interface to access SCSI CD-ROM drives.

The DEV_CDROM feature does not itself export an API.

DEV_MEM

The DEV_MEM feature provides a raw interface to memory devices such as /dev/zero, /dev/null, /dev/kmem, and /dev/mem.

The DEV_MEM feature does not export an API itself, but allows access to the devices listed in the preceding paragraphs.

For details, see the DEV_MEM(5FEA) man page.

DEV_NVRAM

The DEV_NVRAM feature provides an interface to the NVRAM memory device.

For details, see the NVRAM(5FEA) man page.

RAM_DISK

The RAM_DISK feature provides an interface to chunks of memory that can be seen and handled as disks. These disks may then be initialized and used as regular file systems, although their contents will be lost at system shutdown time. This feature is also required to get access to the MS-DOS file system, which is usually embedded as part of the system boot image.

The RAM_DISK feature does not export any APIs itself.

For details, see the RAM_DISK(5FEA) man page.

FLASH

The FLASH feature provides an interface to access a memory device. The flash memory may then be formatted, labelled, and used to support regular file systems. The FLASH feature relies on the flash support based on the Flite 1.2 BSP, and is not supported for all target family architectures. See the appropriate book in the ChorusOS 5.0 Target Platform Collection for details of which target family architecture supports the Flite 1.2 BSP.

The FLASH feature does not itself export an API.

For details, see the FLASH(5FEA) man page.

RAWFLASH

The RAWFLASH feature provides an interface to access a raw memory device. The flash memory may then be formatted, and written to with utilities such as dd. The RAWFLASH feature is mostly used to flash the boot image onto the raw memory device.

For details, see the RAWFLASH(5FEA) man page.

VTTY

The VTTY feature provides support for serial lines on top of the BSP driver for higher levels of protocols. It is used by the PPP feature (see"Point-to-Point Protocol (PPP)" ).

The VTTY feature does not itself export any APIs.

For details, see the VTTY(5FEA) man page.

SCSI_DISK

The SCSI_DISK feature provides an interface to access SCSI disks. The SCSI_DISK feature relies on the SCSI bus support provided by the BSP to access disks connected on that bus.

The SCSI_DISK feature does not itself export an API.

For details, see the SCSI_DISK(5FEA) man page.