mem(4)mem(4)Namemem - physical main memory image
The is a character special file that is an image of the physical main
memory of the computer. It can be used, for example, to examine (and
even to patch) the running system.
Byte addresses in are interpreted as physical memory addresses. Refer‐
ences to nonexistent locations cause errors to be returned.
Examining and patching device registers is likely to lead to unexpected
results when read-only or write-only bits are present.
The memory file is accessed one byte at a time. This may be inappropri‐
ate for some device registers.