[PATCH] STM32H7 doc update

[Robin Mueller]

---

Added doc for board variation, added some  fixes
from code review. (typo and line width formatting)

 user/bsps/arm/stm32h7.rst | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/user/bsps/arm/stm32h7.rst b/user/bsps/arm/stm32h7.rst
index 3eee511..e1b9d8c 100644
--- a/user/bsps/arm/stm32h7.rst
+++ b/user/bsps/arm/stm32h7.rst
@@ -11,16 +11,32 @@ This BSP supports the
 The BSP is known to run on these boards:
 
 * `STM32H743I-EVAL 2 <https://www.st.com/en/evaluation-tools/stm32h743i-eval.html>`_
+* `STM32H743ZI-Nucleo <https://www.st.com/en/evaluation-tools/nucleo-h743zi.html>`_
 
 Clock Driver
 ------------
 
-The clock driver uses the `ARMv7-M Systick` module.
+The clock driver uses the `ARMv7-M Systick` module. The HSE (external 
+oscillator) value can also be different for different evaluation or custom 
+boards, so it is recommended to check the default values of the BSP.
 
 Console Driver
 --------------
 
 The console driver supports the on-chip UART and USART modules.
+Different board variations use different GPIO pins and blocks for the default 
+communication UART and it is recommended to check whether the default 
+configuration provided is valid in the BSP.
+
+To specify that the BSP should be built for the STM32H743ZI-Nucleo board,
+users can supply ``STM32H743ZI_NUCLEO == True`` to ``config.ini`` when 
+building the BSP.
+
+Alternatively, users can supply the configuration structs defined in ``hal.h``
+in the applicaton for other boards. For the console driver, the 
+``stm32h7_usartX_config`` structs are used to configure the GPIO pins and other 
+parameters. The default implementations can be found in 
+``bsps/arm/stm32ht/console`` in the RTEMS sources.
 
 Network Interface Driver
 ------------------------
-- 
2.23.0.windows.1