[examples-v2 commit] README.Makefile: New file

[Joel Sherrill]

Module:    examples-v2
Branch:    master
Commit:    ced65422edc3f95ff670d0974acb8cbf0aa7c263
Changeset: http://git.rtems.org/examples-v2/commit/?id=ced65422edc3f95ff670d0974acb8cbf0aa7c263

Author:    Joel Sherrill <joel at rtems.org>
Date:      Fri Oct 26 16:26:29 2018 -0500

README.Makefile: New file

---

 README.Makefile | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/README.Makefile b/README.Makefile
new file mode 100644
index 0000000..69bb603
--- /dev/null
+++ b/README.Makefile
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+The Makefile system used in these examples is dependent on the
+environment variable RTEMS_MAKEFILE_PATH being set. This can be
+set on each command line that invokes "make" or it can be exported
+into your environment.
+
+RTEMS_MAKEFILE_PATH points to the installed BSP image you are compiling
+for. It is composed as follows:
+
+  @prefix@/@target@/BSP
+
+where:
+
+  - prefix is the BSP install point or prefix
+  - target is the tool target (e.g. sparc-rtems5)
+  - BSP is the BSP you are building for (e.g. erc32)
+
+A coupte of examples:
+
+export RTEMS_MAKEFILE_PATH=${HOME}/rtems-work/tools/5/sparc-rtems5/erc32
+make clean
+make
+
+OR:
+
+RTEMS_MAKEFILE_PATH=${HOME}/rtems-work/tools/5/sparc-rtems5/erc32 make clean
+RTEMS_MAKEFILE_PATH=${HOME}/rtems-work/tools/5/sparc-rtems5/erc32 make
+
+You can switch a build from one BSP to another by changing the value
+of RTEMS_MAKEFILE_PATH but be careful to "make clean" on the old BSP
+before building the new one.
+
+Deprecration Warning: This style of Makefile has been included in RTEMS
+since the earliest days. However, it is being replaced by the use of waf
+and something akin to pkgconfig to obtain compilation settings. The intent
+is to make it easier for users to configure their preferred build system
+for an RTEMS application.