The tools.sh file provides the definitions for variables used for each platform's toolchains.

A single tools.sh file is located at the directory /userdata/conf/tools.sh
This file uses the PLATFORM environment variable to set the variables
for a particular toolchain.

An individual platform file should be named <PLATFORM>-tools.sh, and be
located in the /userdata/toolchains directory.

A new <PLATFORM>-tools.sh files must be added whenever a toolchain or SDK is added to the system.

For example, for the platform 'poky-qemuarm', the file
/userdata/toolchains/poky-qemuarm-tools.sh sets the variables needed
to compile programs with that toolchain.

The variables that should be exported are:
 * CC - C compiler
 * CXX - C++ compiler
 * CPP - C pre-processor 
 * CXXCPP - C++ pre-processor
 * CONFIGURE_FLAGS - flags for the configure script
 * RANLIB - archive index generator (for libs)
 * AS - assembler
 * LD - linker
 * ARCH - architecture
 * CROSS_COMPILE - tool prefix used to build the kernel
 * PREFIX - prefix used with most tools
 * HOST - used with configure --host=$HOST, to specify the machine you are building for
 * SDKROOT - used as prefix for /usr/lib and /usr/include directories

The above variables are directly referenced by the Fuego system.

A few other variables may be used optionally by the build instructions for
individual tests.
 * CFLAGS
 * LDFLAGS

== Variable usage details ==
''Note that some tools variables are referenced in patch files. These don't count as uses from -tools.sh. because they are defined as part of the program build instructions with the program itself.''

Here are some specific tools variables and what tests use them:
 * CFLAGS - compiler flags
   * used by Benchmark.netpipe, Benchmark.cyclictest, Benchmark.tiobench, Benchmark.dbench, Benchmark.ffsh, Benchmark.Dhrystone, Benchmark.lmbench2, Benchmark.himeno, Benchmark.nbench_byte, Benchmark.linpack, Benchmark.GLMark, Benchmakr.Whetstone, Functionall.synctest, Functiona.posixtestsuite, Functiona.scrashme, LTP, Functional.rmaptest, Functional.linus_stress, Functional.crashme
 * LDFLAGS - linker flags
   * used by Benchmark.netpipe, Benchmark.cyclictest, Benchmark.Dhrystone, Benchmark.signaltest, Benchmark.Whetstone, Functional.synctest, Functiona.posixtestsuite, Functiona.scrashme, LTP, Functional.rmaptest, Functional.linus_stress, Functional.crashme
 * HOST - this is passed to 'configure' with --host=$HOST
   * used by Benchmark.aim7, Benchmark.bonnie, Benchmark.dbench, Benchmark.ffsb, Benchmark.x11perf, Benchmark.iperf, Benchmark.gtkperf, Functional.ft2demos, netperf, Functional.glib, and Functional.stress.
 * SDKROOT - used as prefix for /usr/include and /usr/lib directories and files in builds
   * used by Benchmark.aim7, Benchmark.blobsallad, Benchmark.GLMark, Benchmark.GLMark, Benchmark.GLMark, Benchmark.gtkperf, Functional.aiostress, Functional.zlib, LTP, and Functional.ft2demos