@@ -1,90 +1,104 @@
-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".
+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 <jgarzik@pobox.com>
- Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
+Hardware driver for Intel/AMD/VIA Random Number Generators (RNG)
+ - Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
+ - Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
-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.
+About the Intel RNG hardware, from the firmware hub datasheet
+=============================================================
-Intel RNG Driver notes:
+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.
- * FIXME: support poll(2)
+Intel RNG Driver notes
+======================
- 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,
+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.
+ 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:
+Driver details
+==============
- Based on:
+Based on:
Intel 82802AB/82802AC Firmware Hub (FWH) Datasheet
- May 1999 Order Number: 290658-002 R
+ May 1999 Order Number: 290658-002 R
- Intel 82802 Firmware Hub: Random Number Generator
+Intel 82802 Firmware Hub:
+ Random Number Generator
Programmer's Reference Manual
- December 1999 Order Number: 298029-001 R
+ December 1999 Order Number: 298029-001 R
- Intel 82802 Firmware HUB Random Number Generator Driver
+Intel 82802 Firmware HUB Random Number Generator Driver
Copyright (c) 2000 Matt Sottek <msottek@quiknet.com>
- Special thanks to Matt Sottek. I did the "guts", he
- did the "brains" and all the testing.
+Special thanks to Matt Sottek. I did the "guts", he
+did the "brains" and all the testing.
Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - use proper markups for titles; - adjust section identation; - use proper markup for notes and fix it to properly show the numbered list. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> --- Documentation/hw_random.txt | 158 ++++++++++++++++++++++++-------------------- 1 file changed, 86 insertions(+), 72 deletions(-)