website: Added section outlining supported OSs
This new section, added to the Building documentation, outlines what
OSs, compilers, and Python versions are supported. This documents what
is "strongly supported" (i.e., environments we test), as well as
environments in which gem5 should be able compilable and runnable. The
section highlights that docker images, provided by us, may be used to
compile/run gem5 if problems arise.
Change-Id: I0d38c51298ba13b9245aabf8fdc2b4097db6b035
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5-website/+/29048
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: Jason Lowe-Power <power.jg@gmail.com>
diff --git a/_pages/documentation/general_docs/building/index.md b/_pages/documentation/general_docs/building/index.md
index 3482605..5b8948d 100644
--- a/_pages/documentation/general_docs/building/index.md
+++ b/_pages/documentation/general_docs/building/index.md
@@ -9,6 +9,37 @@
# Building gem5
+## Supported operating systems and environments
+
+gem5 has been designed with a Linux environment in mind. We test regularly
+on **Ubuntu 18.04** and **Ubuntu 20.04** to ensure gem5 functions well in
+these environments. Though **any Linux based OS should function if the correct
+dependencies are installed**. We ensure that gem5 is compilable with both gcc
+and clang (see [Dependencies](#dependencies) below for compiler version
+information).
+
+**Mac OS should work when compiling using the clang compiler**, with all other
+dependencies installed. However, at present, we do not officially test our
+builds on Mac OS. **We therefore cannot guarantee the same stability for those
+wishing to compile and run gem5 in Mac OS as we can in Linux-based systems**.
+[In later versions of gem5, we hope to more effectively support Mac OS through
+improved testing](https://gem5.atlassian.net/browse/GEM5-538).
+
+As of gem5 20, **building and running gem5 in both Python 2 and Python 3 are
+supported**. When testing gem5 we primarily test using Ubuntu 18.04 with
+Python 2, and Ubuntu 20.04 with Python 3. We would therefore advice, if
+possible, for users to **utilize Python 2 in Ubuntu 18.04 and Python 3 in
+Ubuntu 20.04**. Though we shall eventually
+[drop support for Python 2](https://gem5.atlassian.net/browse/GEM5-347),
+(due to [its retirement](
+http://pyfound.blogspot.com/2019/12/python-2-sunset.html)), we do not intend to
+do so until we receive ample evidence our community has migrated to Python 3.
+
+If running gem5 in a suitable OS/environment is not possible, we have provided
+pre-prepared [Docker](https://www.docker.com/) images which may be used to
+compile and run gem5. Please see our [Docker](#docker) section below for more
+information on this.
+
## Dependencies
* **git** : gem5 uses git for version control.
