Documented requirements and configure options.

Knot.files

@@ -260,3 +260,4 @@ src/knot/zone/semantic-check.c
 src/knot/zone/semantic-check.h
 src/tests/xfr_tests.h
 src/tests/xfr_tests.c
+doc/knot.texi

doc/knot.texi

@@ -260,7 +260,9 @@ or large number of requests.
 @node CPU Requirements
 @section CPU Requirements
 
-Knot DNS is not very CPU requiring, but it can consume some CPU
+Knot DNS scales with the processing power and also the nubmer of available cores/CPUs.
+There is no lower bound on the CPU requirements, but it should support memory barriers
+and CAS (i586 and newer).
 
 @node Memory Requirements
 @section Memory Requirements
@@ -294,7 +296,21 @@ Linux, FreeBSD, OpenBSD, NetBSD and Mac OS X.
 @node Required build environment
 @section Required build environment
 
-[TODO] Describe lowest needed GCC/Clang, etc.
+GCC at least 4.1 is strictly required for atomic builtins, but 4.2 or newer is recommended.
+Another requirement is _GNU_SOURCE support, otherwise it adapts to the compiler available features.
+Clang should work, but it is not tested nor supported.
+
+Knot DNS build system relies on standard tools:
+@itemize
+@item
+make
+@item
+autoconf >= 2.65
+@item
+flex >= 2.5.31
+@item
+bison >= 2.3
+@end itemize
 
 @node Required libraries
 @section Required libraries
@@ -304,15 +320,19 @@ Knot DNS requires few libraries to be compiled:
 @itemize 
 
 @item
-OpenSSL
-
+OpenSSL, at least 0.9.8
 @item
 zlib
-
 @item
-Userspace RCU
+Userspace RCU, at least 0.5.4
+@item
+libcap-ng, at least 0.6.4 (optional library)
 @end itemize
 
+If libcap-ng library is available, Knot DNS will take advantage of 
+the POSIX 1003.1e capabilites(7) by sandboxing the communication threads.
+Most rights are stripped from the communication threads for security reasons.
+
 You can probably find OpenSSL and zlib libraries already included in
 your system or distribution.  If not, zlib resides at
 @url{http://zlib.net/}, and OpenSSL can be found at
@@ -336,10 +356,11 @@ is possible.  (@url{http://lttng.org/urcu,Userspace RCU})
 Binary packages for Debian can be found under liburcu1 for the
 library and liburcu-dev for development files.
 
-Minimum supported version of Userspace RCU library is 0.4.0,
+Minimum supported version of Userspace RCU library is 0.5.4,
 but we recommend using latest available version.  It is
 especially on non-Linux systems as we got some compatibility
 patches accepted in later releases of Userspace RCU.
+OpenBSD,NetBSD and OS X platforms are supported from version 0.7.0.
 
 @node Installation from the sources
 @section Installation from the sources
@@ -365,6 +386,20 @@ For all available options run:
 @end example
 
 In most simple case you can just run configure without any options.
+If you have trouble with unknown syscalls under valgrind, disable recvmmsg with
+@command{./configure --enable-recvmmsg=no}.
+Also, it has been reported that some platforms have broken LTO (Link time optimizations)
+support, you can disable that by @command{./configure --enable-lto=no}.
+
+If you want to add debug messages, there are two steps to do that.
+First you have to enable modules, that you are interested in.
+Available are: server, zones, xfr, packet, dname, rr, ns, hash, compiler.
+You can combine multiple modules as a comma-separated list.
+For example: @command{./configure --enable-debug=server,packet}
+
+Then you can narrow the verbosity of the debugging message by specifying the
+verbosity as brief, verbose or details.
+For example:  @command{./configure --enable-debuglevel=verbose}.
 
 @example
 
@@ -505,11 +540,13 @@ in the future, when new version are released.
 @node Installing Knot DNS RPMs on Fedora
 @subsection Installing Knot DNS RPMs on Fedora
 
+There are currently no official RPMs.
 [TODO]
 
 @node Installing Knot DNS from ports on FreeBSD
 @subsection Installing Knot DNS from ports on FreeBSD
 
+There is currently no official port on FreeBSD.
 [TODO]
 
 @node Knot DNS Configuration