NAME

mem, kmem, zero, vme16d16, vme24d16, vme32d16, vme16d32, vme24d32, vme32d32, eeprom, atbus, sbus − main memory and bus I/O space

CONFIG

None; included with standard system. 

DESCRIPTION

These devices are special files that map memory and bus I/O space.  They may be read, written, seeked and (except for kmem) memory-mapped.  See read(2V), write(2V), mmap(2), and directory(3V). 

All Systems

mem is a special file that is an image of the physical memory of the computer.  It may be used, for example, to examine (and even to patch) the system. 

kmem is a special file that is an image of the kernel virtual memory of the system. 

zero is a special file which is a source of private zero pages. 

eeprom is a special file that is an image of the EEPROM or NVRAM. 

Sun-3 and Sun-4 Systems VMEbus

vme16d16 (also known as vme16) is a special file that is an image of VMEbus 16-bit addresses with 16-bit data.  vme16 address space extends from 0 to 64K. 

vme24d16 (also known as vme24) is a special file that is an image of VMEbus 24-bit addresses with 16-bit data.  vme24 address space extends from 0 to 16 Megabytes.  The VME 16-bit address space overlaps the top 64K of the 24-bit address space. 

vme32d16 is a special file that is an image of VMEbus 32-bit addresses with 16-bit data. 

vme16d32 is a special file that is an image of VMEbus 16-bit addresses with 32-bit data. 

vme24d32 is a special file that is an image of VMEbus 24-bit addresses with 32-bit data. 

vme32d32 (also known as vme32) is a special file that is an image of VMEbus 32-bit addresses with 32-bit data.  vme32 address space extends from 0 to 4 Gigabytes.  The VME 24-bit address space overlaps the top 16 Megabytes of the 32-bit address space. 

Desktop SPARCsystems

The sbus is represented by a series of entries each of which is an image of a single sbus slot.  The entries are named sbusn, where n is the slot number in hexadecimal.  The number of sbus slots and the address range within each slot may vary between implementations. 

Sun386i Systems

atbus is a special file that is an image of the AT bus space.  It extends from 0 to 16 Megabytes. 

FILES

/dev/mem

/dev/kmem

/dev/zero

/dev/vme16d16

/dev/vme16

/dev/vme24d16

/dev/vme24

/dev/vme32d16

/dev/vme16d32

/dev/vme24d32

/dev/vme32d32

/dev/vme32

/dev/eeprom

/dev/atbus

/dev/sbus[0-3]

SEE ALSO

mmap(2), read(2V), write(2V), directory(3V)

Sun Release 4.1  —  Last change: 7 October 1990