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kmem(7) [osf1 man page]

kmem(7) 						 Miscellaneous Information Manual						   kmem(7)

kmem - mapped kernel memory interface DESCRIPTION
The kmem character special device provides access to mapped kernel memory. Byte addresses in kmem are equivalent to mapped kernel memory addresses. References to unmapped or user space addresses will return an error. Write accesses to console or PAL memory or to memory protected against writes will also return an error. RESTRICTIONS
Because memory is read and written in aligned quadwords (eight contiguous bytes), writing fewer than all the bytes in an aligned quadword is a read-modify-write operation that is not protected against writes to the same quadword. Device registers are accessed as aligned quadwords through kmem. The kmem file is not available as a memory mapped file. FILES
mem(7) delim off kmem(7)

Check Out this Related Man Page

MEM(4)                                                       Linux Programmer's Manual                                                      MEM(4)

mem, kmem, port - system memory, kernel memory and system ports DESCRIPTION
/dev/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 /dev/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. Since Linux 2.6.26, and depending on the architecture, the CONFIG_STRICT_DEVMEM kernel configuration option limits the areas which can be accessed through this file. For example: on x86, RAM access is not allowed but accessing memory-mapped PCI regions is. It is typically created by: mknod -m 660 /dev/mem c 1 1 chown root:kmem /dev/mem The file /dev/kmem is the same as /dev/mem, except that the kernel virtual memory rather than physical memory is accessed. Since Linux 2.6.26, this file is available only if the CONFIG_DEVKMEM kernel configuration option is enabled. It is typically created by: mknod -m 640 /dev/kmem c 1 2 chown root:kmem /dev/kmem /dev/port is similar to /dev/mem, but the I/O ports are accessed. It is typically created by: mknod -m 660 /dev/port c 1 4 chown root:kmem /dev/port FILES
/dev/mem /dev/kmem /dev/port SEE ALSO
chown(1), mknod(1), ioperm(2) COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at Linux 2015-01-02 MEM(4)
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