From 4f4cfa6c560c93ba180c30675cf845e1597de44c Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 27 Jun 2019 14:56:51 -0300 Subject: docs: admin-guide: add a series of orphaned documents There are lots of documents that belong to the admin-guide but are on random places (most under Documentation root dir). Move them to the admin guide. Signed-off-by: Mauro Carvalho Chehab Acked-by: Alexandre Belloni Acked-by: Bartlomiej Zolnierkiewicz --- Documentation/hw_random.txt | 105 -------------------------------------------- 1 file changed, 105 deletions(-) delete mode 100644 Documentation/hw_random.txt (limited to 'Documentation/hw_random.txt') diff --git a/Documentation/hw_random.txt b/Documentation/hw_random.txt deleted file mode 100644 index 121de96e395e..000000000000 --- a/Documentation/hw_random.txt +++ /dev/null @@ -1,105 +0,0 @@ -========================================================== -Linux support for random number generator in i8xx chipsets -========================================================== - -Introduction -============ - -The hw_random framework is software that makes use of a -special hardware feature on your CPU or motherboard, -a Random Number Generator (RNG). The software has two parts: -a core providing the /dev/hwrng character device and its -sysfs support, plus a hardware-specific driver that plugs -into that core. - -To make the most effective use of these mechanisms, you -should download the support software as well. Download the -latest version of the "rng-tools" package from the -hw_random driver's official Web site: - - http://sourceforge.net/projects/gkernel/ - -Those tools use /dev/hwrng to fill the kernel entropy pool, -which is used internally and exported by the /dev/urandom and -/dev/random special files. - -Theory of operation -=================== - -CHARACTER DEVICE. Using the standard open() -and read() system calls, you can read random data from -the hardware RNG device. This data is NOT CHECKED by any -fitness tests, and could potentially be bogus (if the -hardware is faulty or has been tampered with). Data is only -output if the hardware "has-data" flag is set, but nevertheless -a security-conscious person would run fitness tests on the -data before assuming it is truly random. - -The rng-tools package uses such tests in "rngd", and lets you -run them by hand with a "rngtest" utility. - -/dev/hwrng is char device major 10, minor 183. - -CLASS DEVICE. There is a /sys/class/misc/hw_random node with -two unique attributes, "rng_available" and "rng_current". The -"rng_available" attribute lists the hardware-specific drivers -available, while "rng_current" lists the one which is currently -connected to /dev/hwrng. If your system has more than one -RNG available, you may change the one used by writing a name from -the list in "rng_available" into "rng_current". - -========================================================================== - - -Hardware driver for Intel/AMD/VIA Random Number Generators (RNG) - - Copyright 2000,2001 Jeff Garzik - - Copyright 2000,2001 Philipp Rumpf - - -About the Intel RNG hardware, from the firmware hub datasheet -============================================================= - -The Firmware Hub integrates a Random Number Generator (RNG) -using thermal noise generated from inherently random quantum -mechanical properties of silicon. When not generating new random -bits the RNG circuitry will enter a low power state. Intel will -provide a binary software driver to give third party software -access to our RNG for use as a security feature. At this time, -the RNG is only to be used with a system in an OS-present state. - -Intel RNG Driver notes -====================== - -FIXME: support poll(2) - -.. note:: - - request_mem_region was removed, for three reasons: - - 1) Only one RNG is supported by this driver; - 2) The location used by the RNG is a fixed location in - MMIO-addressable memory; - 3) users with properly working BIOS e820 handling will always - have the region in which the RNG is located reserved, so - request_mem_region calls always fail for proper setups. - However, for people who use mem=XX, BIOS e820 information is - **not** in /proc/iomem, and request_mem_region(RNG_ADDR) can - succeed. - -Driver details -============== - -Based on: - Intel 82802AB/82802AC Firmware Hub (FWH) Datasheet - May 1999 Order Number: 290658-002 R - -Intel 82802 Firmware Hub: - Random Number Generator - Programmer's Reference Manual - December 1999 Order Number: 298029-001 R - -Intel 82802 Firmware HUB Random Number Generator Driver - Copyright (c) 2000 Matt Sottek - -Special thanks to Matt Sottek. I did the "guts", he -did the "brains" and all the testing. -- cgit v1.2.3