[edk2-platforms][PATCH 1/4] RPi3/RPi4: document 3A+ support.

["Andrei Warkentin" <andrey.warkentin@gmail.com>]

The RPi3 target also supports the 3A+, so let's document it.

(The 3A+ lacks the ethernet port and has less RAM)

Clarify RPi3 is for BCM2837-based variants, while RPi4 is
for the BCM2711-based variants.

Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>
---
 Platform/RaspberryPi/RPi3/Readme.md | 23 ++++++++++++++------
 Platform/RaspberryPi/RPi4/Readme.md | 15 ++++++++++---
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/Platform/RaspberryPi/RPi3/Readme.md b/Platform/RaspberryPi/RPi3/Readme.md
index 05f498ee..d63d6767 100644
--- a/Platform/RaspberryPi/RPi3/Readme.md
+++ b/Platform/RaspberryPi/RPi3/Readme.md
@@ -1,19 +1,28 @@
-Raspberry Pi Platform
-=====================
+Raspberry Pi 3 Platform
+=======================
 
 # Summary
 
-This is a port of 64-bit Tiano Core UEFI firmware for the Raspberry Pi 3/3B+ platforms,
-based on [Ard Bisheuvel's 64-bit](http://www.workofard.com/2017/02/uefi-on-the-pi/)
+This is a port of 64-bit Tiano Core UEFI firmware for the Raspberry Pi 3B (and related)
+platforms, based on [Ard Bisheuvel's 64-bit](http://www.workofard.com/2017/02/uefi-on-the-pi/)
 and [Microsoft's 32-bit](https://github.com/ms-iot/RPi-UEFI/tree/ms-iot/Pi3BoardPkg)
 implementations, as maintained by [Andrei Warkentin](https://github.com/andreiw/RaspberryPiPkg).
 
-This is meant as a generally useful 64-bit ATF + UEFI implementation for the Raspberry
-Pi 3/3B+ which should be good enough for most kind of UEFI development, as well as for
-running consummer Operating Systems in such as Linux or Windows.
+This is meant as a generally useful 64-bit ATF + UEFI implementation for Raspberry Pi
+variants based on the BCM2837 SoC, which should be good enough for most kind of UEFI development,
+as well as for running consummer Operating Systems in such as Linux, Windows or the BSDs.
 
 Raspberry Pi is a trademark of the [Raspberry Pi Foundation](http://www.raspberrypi.org).
 
+# Hardware Supported
+
+The RPi3 target supports Pi revisions based on the BCM2837 SoC:
+- Raspberry Pi 3A+
+- Raspberry Pi 3B
+- Raspberry Pi 3B+
+
+Please see the RPi4 target for BCM2711-based variants, such as the Raspberry Pi 4B.
+
 # Status
 
 This firmware, that has been validated to compile against the current
diff --git a/Platform/RaspberryPi/RPi4/Readme.md b/Platform/RaspberryPi/RPi4/Readme.md
index fa9b3146..1f4ed001 100644
--- a/Platform/RaspberryPi/RPi4/Readme.md
+++ b/Platform/RaspberryPi/RPi4/Readme.md
@@ -3,14 +3,23 @@ Raspberry Pi 4 Platform
 
 # Summary
 
-This is a port of 64-bit Tiano Core UEFI firmware for the Raspberry Pi 4 platforms.
+This is a port of 64-bit Tiano Core UEFI firmware for the Raspberry Pi 4B platform.
 
 This is intended to be useful 64-bit [TF-A](https://www.trustedfirmware.org/) +
-UEFI implementation for the Raspberry Pi 4 which should be good enough for most
-kind of UEFI development, as well as for running consummer Operating Systems.
+UEFI implementation for the Raspberry Pi variants based on the BCM2711 SoC,
+which should be good enough for most kind of UEFI development, as well running consumer
+Operating Systems.
 
 Raspberry Pi is a trademark of the [Raspberry Pi Foundation](https://www.raspberrypi.org).
 
+# Hardware Supported
+
+The RPi4 target supports Pi revisions based on the BCM2711 SoC:
+- Raspberry Pi 4B
+
+Please see the RPi3 target for the BCM2837-based variants, such as the Raspberry
+Pi 3B.
+
 # Status
 
 This firmware is still in development stage, meaning that it comes with the
-- 
2.17.1