/dev/mem and /dev/kmem

最新推荐文章于 2023-05-27 22:44:10 发布

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本文详细介绍了内核内存设备，包括mem、kmem和port的功能、用途及创建方式，解释了如何通过这些设备访问和操作计算机的内存，以及注意事项。

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直接来自：man mem

NAME
mem, kmem, port - system memory, kernel memory and system ports

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

Byte addresses in mem are interpreted as physical memory addresses. References to
nonexistent locations cause errors to be returned.

Examining and patching is likely to lead to unexpected results when read-only or
write-only bits are present.

It is typically created by:

mknod -m 660 /dev/mem c 1 1
chown root:kmem /dev/mem

The file kmem is the same as mem, except that the kernel virtual memory rather than
physical memory is accessed.

It is typically created by:

mknod -m 640 /dev/kmem c 1 2
chown root:kmem /dev/kmem

port is similar to mem, but the I/O ports are accessed.

It is typically created by:

mknod -m 660 /dev/port c 1 4
chown root:mem /dev/port

FILES
/dev/mem
/dev/kmem
/dev/port