stm32/README: Update to reflect current MCU support.
MicroPython port to STM32 MCUs
==============================
-This directory contains the port of MicroPython to ST's line of STM32Fxxx
-microcontrollers. It is based on the STM32Cube HAL library and currently
-supports: STM32F401, STM32F405, STM32F411, STM32F429, STM32F746.
+This directory contains the port of MicroPython to ST's line of STM32
+microcontrollers. Supported MCU series are: STM32F4, STM32F7 and STM32L4.
+Parts of the code here utilise the STM32Cube HAL library.
The officially supported boards are the line of pyboards: PYBv1.0 and PYBv1.1
(both with STM32F405), and PYBLITEv1.0 (with STM32F411). See
@@ -14,6 +14,12 @@ Other boards that are supported include ST Discovery and Nucleo boards.
See the boards/ subdirectory, which contains the configuration files used
to build each individual board.
+The STM32H7 series has preliminary support: there is a working REPL via
+USB and UART, as well as very basic peripheral support, but some things do
+not work and none of the advanced features of the STM32H7 are yet supported,
+such as the clock tree. At this point the STM32H7 should be considered as a
+fast version of the STM32F7.
+
Build instructions
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