[PATCH v3 3/4] docs/system: arm: Add stm32 boards description

[Alexandre Iooss <erdnaxe@crans.org>]

This adds the target guide for Netduino 2, Netduino Plus 2 and STM32VLDISCOVERY.

Signed-off-by: Alexandre Iooss <erdnaxe@crans.org>
---
 MAINTAINERS                |  1 +
 docs/system/arm/stm32.rst  | 66 ++++++++++++++++++++++++++++++++++++++
 docs/system/target-arm.rst |  1 +
 3 files changed, 68 insertions(+)
 create mode 100644 docs/system/arm/stm32.rst

diff --git a/MAINTAINERS b/MAINTAINERS
index 0aa8016936..47fb06e5fc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -896,6 +896,7 @@ M: Alexandre Iooss <erdnaxe@crans.org>
 L: qemu-arm@nongnu.org
 S: Maintained
 F: hw/arm/stm32vldiscovery.c
+F: docs/system/arm/stm32.rst
 
 Versatile Express
 M: Peter Maydell <peter.maydell@linaro.org>
diff --git a/docs/system/arm/stm32.rst b/docs/system/arm/stm32.rst
new file mode 100644
index 0000000000..508b92cf86
--- /dev/null
+++ b/docs/system/arm/stm32.rst
@@ -0,0 +1,66 @@
+STMicroelectronics STM32 boards (``netduino2``, ``netduinoplus2``, ``stm32vldiscovery``)
+========================================================================================
+
+The `STM32`_ chips are a family of 32-bit ARM-based microcontroller by
+STMicroelectronics.
+
+.. _STM32: https://www.st.com/en/microcontrollers-microprocessors/stm32-32-bit-arm-cortex-mcus.html
+
+The STM32F1 series is based on ARM Cortex-M3 core. The following machines are
+based on this chip :
+
+- ``stm32vldiscovery``  STM32VLDISCOVERY board with STM32F100RBT6 microcontroller
+
+The STM32F2 series is based on ARM Cortex-M3 core. The following machines are
+based on this chip :
+
+- ``netduino2``         Netduino 2 board with STM32F205RFT6 microcontroller
+
+The STM32F4 series is based on ARM Cortex-M4F core. This series is pin-to-pin
+compatible with STM32F2 series. The following machines are based on this chip :
+
+- ``netduinoplus2``     Netduino Plus 2 board with STM32F405RGT6 microcontroller
+
+There are many other STM32 series that are currently not supported by QEMU.
+
+Supported devices
+-----------------
+
+ * ARM Cortex-M3, Cortex M4F
+ * Analog to Digital Converter (ADC)
+ * EXTI interrupt
+ * Serial ports (USART)
+ * SPI controller
+ * System configuration (SYSCFG)
+ * Timer controller (TIMER)
+
+Missing devices
+---------------
+
+ * Camera interface (DCMI)
+ * Controller Area Network (CAN)
+ * Cycle Redundancy Check (CRC) calculation unit
+ * Digital to Analog Converter (DAC)
+ * DMA controller
+ * Ethernet controller
+ * Flash Interface Unit
+ * GPIO controller
+ * I2C controller
+ * Inter-Integrated Sound (I2S) controller
+ * Power supply configuration (PWR)
+ * Random Number Generator (RNG)
+ * Real-Time Clock (RTC) controller
+ * Reset and Clock Controller (RCC)
+ * Secure Digital Input/Output (SDIO) interface
+ * USB OTG
+ * Watchdog controller (IWDG, WWDG)
+
+Boot options
+------------
+
+The STM32 machines can be started using the ``-kernel`` option to load a
+firmware. Example:
+
+.. code-block:: bash
+
+  $ qemu-system-arm -M stm32vldiscovery -kernel firmware.bin
diff --git a/docs/system/target-arm.rst b/docs/system/target-arm.rst
index edd013c7bb..addd3d1613 100644
--- a/docs/system/target-arm.rst
+++ b/docs/system/target-arm.rst
@@ -96,6 +96,7 @@ undocumented; you can get a complete list by running
    arm/collie
    arm/sx1
    arm/stellaris
+   arm/stm32
    arm/virt
    arm/xlnx-versal-virt
 
-- 
2.25.1