Minor doc enhancements to INSTALL.md

Describe current relationship between config and Configure.
Put the environment variable list in alphabetical order.
Add description of KERNEL_BITS.
Add new variable CONFIG_NOWAIT.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16325)

1 files changed, 23 insertions, 14 deletions

diff --git a/INSTALL.md b/INSTALL.md
index c717dfcdf0..f483c0e8a0 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -1142,11 +1142,9 @@ Configure OpenSSL
 
 ### Automatic Configuration
 
-On some platform a `config` script is available which attempts to guess
-your operating system (and compiler, if necessary) and calls the `Configure`
-Perl script with appropriate target based on its guess.  Further options can
-be supplied to the `config` script, which will be passed on to the `Configure`
-script.
+In previous version, the `config` script determined the platform type and
+compiler and then called `Configure`. Starting with this release, they are
+the same.
 
 #### Unix / Linux / macOS
 
@@ -1406,11 +1404,29 @@ over the build process.  Typically these should be defined prior to running
                    using this variable. Set it to the compiler executable you wish
                    to use, e.g. gcc or clang.
 
+    CONFIG_NOWAIT
+                   On platforms where the choice of 32-bit or 64-bit architecture
+                   is not explicitly specified, `Configure` will print a warning
+                   message and wait for a few seconds to let you interrupt the
+                   configuration. Setting this variable will skip the wait.
+
     CROSS_COMPILE
                    This environment variable has the same meaning as for the
                    "--cross-compile-prefix" Configure flag described above. If both
                    are set then the Configure flag takes precedence.
 
+    HASHBANGPERL
+                   The command string for the Perl executable to insert in the
+                   #! line of perl scripts that will be publicly installed.
+                   Default: /usr/bin/env perl
+                   Note: the value of this variable is added to the same scripts
+                   on all platforms, but it's only relevant on Unix-like platforms.
+
+    KERNEL_BITS
+                   This can be the value `32` or `64` to specify the architecture
+                   when it is not "obvious" to the configuration. It should generally
+                   not be necessary to specify this environment variable.
+
     NM
                    The name of the nm executable to use.
 
@@ -1435,12 +1451,8 @@ over the build process.  Typically these should be defined prior to running
                    Only needed if builing should use a different Perl executable
                    than what is used to run the Configure script.
 
-    HASHBANGPERL
-                   The command string for the Perl executable to insert in the
-                   #! line of perl scripts that will be publicly installed.
-                   Default: /usr/bin/env perl
-                   Note: the value of this variable is added to the same scripts
-                   on all platforms, but it's only relevant on Unix-like platforms.
+    RANLIB
+                   The name of the ranlib executable to use.
 
     RC
                    The name of the rc executable to use. The default will be as
@@ -1449,9 +1461,6 @@ over the build process.  Typically these should be defined prior to running
                    variable is synonymous to this. If both are defined then RC
                    takes precedence.
 
-    RANLIB
-                   The name of the ranlib executable to use.
-
     WINDRES
                    See RC.