docs/system/arm: Add a doc for zynq board

Added the supported device list and an example command.

Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@amd.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Reviewed-by: Francisco Iglesias <francisco.iglesias@amd.com>
Message-id: 20240621125906.1300995-4-sai.pavan.boddu@amd.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

MAINTAINERS

@@ -1033,6 +1033,7 @@ F: hw/adc/zynq-xadc.c
 F: include/hw/misc/zynq_slcr.h
 F: include/hw/adc/zynq-xadc.h
 X: hw/ssi/xilinx_*
+F: docs/system/arm/xlnx-zynq.rst
 
 Xilinx ZynqMP and Versal
 M: Alistair Francis <alistair@alistair23.me>

docs/system/arm/xlnx-zynq.rst

@@ -0,0 +1,47 @@
+Xilinx Zynq board (``xilinx-zynq-a9``)
+======================================
+The Zynq 7000 family is based on the AMD SoC architecture. These products
+integrate a feature-rich dual or single-core Arm Cortex-A9 MPCore based
+processing system (PS) and AMD programmable logic (PL) in a single device.
+
+More details here:
+https://docs.amd.com/r/en-US/ug585-zynq-7000-SoC-TRM/Zynq-7000-SoC-Technical-Reference-Manual
+
+QEMU xilinx-zynq-a9 board supports following devices:
+    - A9 MPCORE
+        - cortex-a9
+        - GIC v1
+        - Generic timer
+        - wdt
+    - OCM 256KB
+    - SMC SRAM@0xe2000000 64MB
+    - Zynq SLCR
+    - SPI x2
+    - QSPI
+    - UART
+    - TTC x2
+    - Gigabit Ethernet Controller x2
+    - SD Controller x2
+    - XADC
+    - Arm PrimeCell DMA Controller
+    - DDR Memory
+    - USB 2.0 x2
+
+Running
+"""""""
+Direct Linux boot of a generic ARM upstream Linux kernel:
+
+.. code-block:: bash
+
+  $ qemu-system-aarch64 -M xilinx-zynq-a9 \
+        -dtb zynq-zc702.dtb  -serial null -serial mon:stdio \
+        -display none  -m 1024 \
+        -initrd rootfs.cpio.gz -kernel zImage
+
+For configuring the boot-mode provide the following on the command line:
+
+.. code-block:: bash
+
+   -machine boot-mode=qspi
+
+Supported values are jtag, sd, qspi, nor.

docs/system/target-arm.rst

@@ -109,6 +109,7 @@ undocumented; you can get a complete list by running
    arm/virt
    arm/xenpvh
    arm/xlnx-versal-virt
+   arm/xlnx-zynq
 
 Emulated CPU architecture support
 =================================