Documentation: various improvements for stm32xx documentation

Documentation/platforms/arm/stm32h7/index.rst

@@ -10,7 +10,63 @@ TODO
 Peripheral Support
 ==================
 
-TODO
+
+The following list indicates peripherals supported in NuttX:
+
+==========  =======  =====
+Peripheral  Support  Notes
+==========  =======  =====
+RAMECC      No
+FLASH       Yes
+SMM         No
+PM          ?
+RCC         Yes
+CRS         No
+HSEM        Yes
+GPIO        Yes
+SYSCFG      Yes
+MDMA        ?
+DMA         Yes
+BDMA        Yes
+DMA2D       Yes
+EXTI        Yes
+CRC         Yes
+FMC         Yes
+QUADSPI     Yes
+DLYB        No
+ADC         Yes
+DAC         Yes
+VREFBUF     No
+COMP        No
+OPAMP       No
+DFSDM       No
+DCMI        No
+LTDC        Yes
+JPEG        No
+RNG         Yes
+CRYP        No
+HASH        ?
+HRTIM       No
+TIM         Yes
+LPTIM       No
+IWDG        Yes
+WWDG        Yes
+RTC         Yes
+I2C         Yes
+USART       Yes
+SPI         Yes
+I2S         ?
+SAI         No
+SPIDIFRX    No
+SWPMI       No
+MDIOS       ?
+SDMMC       Yes
+FDCAN       Yes
+OTG_FS      Yes
+OTG_HS      Yes
+ETH         Yes
+HDMI_CEC    No
+==========  =======  =====
 
 Supported Boards
 ================