X-Git-Url: http://git.hcoop.net/bpt/guile.git/blobdiff_plain/cfad56a4449011e34aa917136cb6844ef453edcc..HEAD:/README

diff --git a/README b/README
index 256b7d0d6..92d786c06 100644
--- a/README
+++ b/README
@@ -62,7 +62,7 @@ Required External Packages ================================================
 
 Guile requires the following external packages:
 
-  - GNU MP, at least version 4.1
+  - GNU MP, at least version 4.2
 
     GNU MP is used for bignum arithmetic.  It is available from
     http://gmplib.org/ .
@@ -72,7 +72,7 @@ Guile requires the following external packages:
     libltdl is used for loading extensions at run-time.  It is
     available from http://www.gnu.org/software/libtool/ .
 
-  - GNU libunistring
+  - GNU libunistring, at least version 0.9.3
 
     libunistring is used for Unicode string operations, such as the
     `utf*->string' procedures.  It is available from
@@ -82,7 +82,7 @@ Guile requires the following external packages:
 
     libgc (aka. the Boehm-Demers-Weiser garbage collector) is the
     conservative garbage collector used by Guile.  It is available
-    from http://www.hpl.hp.com/personal/Hans_Boehm/gc/ .
+    from http://www.hboehm.info/gc/ .
 
   - libffi
 
@@ -93,10 +93,15 @@ Guile requires the following external packages:
   - pkg-config
 
     Guile's ./configure script uses pkg-config to discover the correct
-    compile and link options for libgc and libffi.  If you don't have
-    pkg-config installed, or you have a version of libgc that doesn't
-    provide a .pc file, you can work around this by setting some
-    variables as part of the configure command-line:
+    compile and link options for libgc and libffi.  For this to work,
+    the `PKG_CONFIG_PATH' environment variable must be set to point to
+    the places where libgc's and libffi's `.pc' files can be found:
+
+      PKG_CONFIG_PATH=/path/to/libgc/lib/pkgconfig:/path/to/libffi/lib/pkgconfig
+
+    Alternatively, when pkg-config is not installed, you can work around
+    this by setting some variables as part of the configure
+    command-line:
 
     - PKG_CONFIG=true
 
@@ -239,25 +244,28 @@ switches specific to Guile you may find useful in some circumstances.
 
 Cross building Guile  =====================================================
 
-As of guile-1.5.x, the build process uses compiled C files for
-snarfing, and (indirectly, through libtool) for linking, and uses the
-guile executable for generating documentation.
+As of Guile 2.0.x, the build process produces a library, libguile-2.0,
+along with Guile "object files" containing bytecode to be interpreted by
+Guile's virtual machine.  The bytecode format depends on the endianness
+and word size of the host CPU.
 
-When cross building guile, you first need to configure, build and
-install guile for your build host.
+Thus, when cross building Guile, you first need to configure, build and
+install it for your build host.
 
-Then, you may configure guile for cross building, eg:
+Then, you may configure Guile for cross building:
 
     ./configure --host=i686-pc-cygwin --disable-shared
 
-A C compiler for the build system is required.  The default is
-"PATH=/usr/bin:$PATH cc".  If that doesn't suit it can be specified
-with the CC_FOR_BUILD variable in the usual way, for instance
+A C compiler for the build system is required.  If that doesn't suit it
+can be specified with the CC_FOR_BUILD variable in the usual way, for
+instance:
 
     ./configure --host=m68k-unknown-linux-gnu CC_FOR_BUILD=/my/local/gcc
 
 Guile for the build system can be specified similarly with the
-GUILE_FOR_BUILD variable, it defaults to just "guile".
+GUILE_FOR_BUILD variable, which defaults to whatever `guile' executable
+is found in $PATH.  It must have the exact same version has the Guile
+that you intend to cross-build.
 
 
 Using Guile Without Installing It =========================================