doc: add atkbdc emulation doc

add AT keyboard controller emulation doc and entry

Signed-off-by: Gao Junhao <junhao.gao@intel.com>

doc/developer-guides/hld/atkbdc-virt-hld.rst

@@ -0,0 +1,77 @@
+.. _atkbdc_virt_hld:
+
+AT keyboard controller emulation
+################################
+
+This document describes AT keyboard controller emulation implementation in ACRN device model. Atkbdc device emulates a PS2 keyboard and mouse.
+
+Overview
+********
+
+The PS2 port is a 6-pin mini-Din connector used for connecting keyboards and mice to a PC compatible computer system. Its name comes from the IBM Personal System/2 series of personal computers, with which it was introduced in 1987. PS2 keyboard/mouse emulation is based on ACPI Emulation. We can add ACPI description of PS2 keyboard/mouse into virtual DSDT table to emulate keyboard/mouse in the User VM.
+
+.. figure:: images/atkbdc-virt-hld.png
+   :align: center
+   :name: atkbdc-virt-arch
+
+   AT keyboard controller emulation architecture
+
+PS2 keyboard emulation
+**********************
+
+ACRN supports AT keyboard controller for PS2 keyboard that can be accessed through I/O ports(0x60 and 0x64). 0x60 is used to access AT keyboard controller data register, 0x64 is used to access AT keyboard controller address register. 
+
+The PS2 keyboard ACPI description as below::
+
+        Device (KBD)
+        {
+                Name (_HID, EisaId ("PNP0303") /* IBM Enhanced Keyboard (101/102-key, PS/2 Mouse) */) // _HID: Hardware ID
+                Name (_CRS, ResourceTemplate () // _CRS: Current Resource Settings
+                {
+                        IO (Decode16,
+                            0x0060, // Range Minimum
+                            0x0060, // Range Maximum
+                            0x01, // Alignment
+                            0x01, // Length
+                            )
+                        IO (Decode16,
+                            0x0064, // Range Minimum
+                            0x0064, // Range Maximum
+                            0x01, // Alignment
+                            0x01, // Length
+                            )
+                        IRQNoFlags ()
+                           {1}
+                })
+        }
+
+PS2 mouse emulation
+*******************
+
+ACRN supports AT keyboard controller for PS2 mouse that can be accessed through I/O ports(0x60 and 0x64).
+0x60 is used to access AT keyboard controller data register, 0x64 is used to access AT keyboard controller address register.
+
+The PS2 mouse ACPI description as below::
+
+        Device (MOU)
+        {
+                Name (_HID, EisaId ("PNP0F13") /* PS/2 Mouse */) // _HID: Hardware ID
+                Name (_CRS, ResourceTemplate () // _CRS: Current Resource Settings
+                {
+                        IO (Decode16,
+                            0x0060, // Range Minimum
+                            0x0060, // Range Maximum
+                            0x01, // Alignment
+                            0x01, // Length
+                            )
+                        IO (Decode16,
+                            0x0064, // Range Minimum
+                            0x0064, // Range Maximum
+                            0x01, // Alignment
+                            0x01, // Length
+                            )
+                        IRQNoFlags ()
+                           {12}
+                })
+        }
+

doc/developer-guides/hld/hld-emulated-devices.rst

@@ -20,3 +20,4 @@ documented in this section.
    UART emulation in hypervisor <vuart-virt-hld>
    RTC emulation in hypervisor <rtc-virt-hld>
    Hostbridge emulation <hostbridge-virt-hld>
+   AT keyboard controller emulation <atkbdc-virt-hld>