The purpose of cross-compiling is to build a Berkeley DB library on one platform that is to be used on a different platform. This section demonstrates how to build a library compatible with the ARM platform from a 32-bit x86 Linux platform. You will need to adjust the build tools and options to match your particular platforms.
Download, install, and test a toolchain that can
build the desired target binaries. In this example, we
use the arm-linux-gnueabi-gcc
package.
Decide on your configuration options, and set up your environment to use the appropriate compiler and compiler tools. It is often easiest to set this up as a small shell script. For example:
#!/bin/sh -f env \ CC=/usr/bin/arm-linux-gnueabi-gcc \ STRIP=/usr/bin/arm-linux-gnueabi-strip \ ../dist/configure \ --build=i686-pc-linux-gnu \ --host=arm-linux-gnueabi \ --enable-java \ --enable-sql \ --enable-jdbc \ --enable-smallbuild \ --enable-shared \ --enable-stripped_messages \ --prefix=$HOME/ARM-linux/install \ $*
The --build flag indicates the
system on which you are compiling and the
--host flag indicates the
target platform. Adjust or omit the
--enable and
--prefix flag settings as
dictated by your own needs.
Unpack your Berkeley DB distribution and go to the
build_unix directory.
Alternatively, you may create a more
appropriately-named directory at the same level and
build in it. For example,
build_arm.
In your build directory, configure by executing
your script, then make and
make install. Review any
compiler warnings and fix if necessary, repeating the
configure and
make steps until you are
satisfied. The resulting libraries and executables can
then be transferred to your target system.