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+:orphan:
+
+==========================================
+loongson3 virt generic platform (``virt``)
+==========================================
+
+The ``virt`` machine use gpex host bridge, and there are some
+emulated devices on virt board, such as loongson7a RTC device,
+IOAPIC device, ACPI device and so on.
+
+Supported devices
+-----------------
+
+The ``virt`` machine supports:
+- Gpex host bridge
+- Ls7a RTC device
+- Ls7a IOAPIC device
+- ACPI GED device
+- Fw_cfg device
+- PCI/PCIe devices
+- Memory device
+- CPU device. Type: la464.
+
+CPU and machine Type
+--------------------
+
+The ``qemu-system-loongarch64`` provides emulation for virt
+machine. You can specify the machine type ``virt`` and
+cpu type ``la464``.
+
+Boot options
+------------
+
+We can boot the LoongArch virt machine by specifying the uefi bios,
+initrd, and linux kernel. And those source codes and binary files
+can be accessed by following steps.
+
+(1) Build qemu-system-loongarch64:
+
+.. code-block:: bash
+
+  ./configure --disable-rdma --disable-pvrdma --prefix=/usr \
+              --target-list="loongarch64-softmmu" \
+              --disable-libiscsi --disable-libnfs --disable-libpmem \
+              --disable-glusterfs --enable-libusb --enable-usb-redir \
+              --disable-opengl --disable-xen --enable-spice \
+              --enable-debug --disable-capstone --disable-kvm \
+              --enable-profiler
+  make -j8
+
+(2) Set cross tools:
+
+.. code-block:: bash
+
+  wget https://github.com/loongson/build-tools/releases/download/2022.09.06/loongarch64-clfs-6.3-cross-tools-gcc-glibc.tar.xz
+
+  tar -vxf loongarch64-clfs-6.3-cross-tools-gcc-glibc.tar.xz  -C /opt
+
+  export PATH=/opt/cross-tools/bin:$PATH
+  export LD_LIBRARY_PATH=/opt/cross-tools/lib:$LD_LIBRARY_PATH
+  export LD_LIBRARY_PATH=/opt/cross-tools/loongarch64-unknown-linux-gnu/lib/:$LD_LIBRARY_PATH
+
+Note: You need get the latest cross-tools at https://github.com/loongson/build-tools
+
+(3) Build BIOS:
+
+    See: https://github.com/tianocore/edk2-platforms/tree/master/Platform/Loongson/LoongArchQemuPkg#readme
+
+Note: To build the release version of the bios,  set --buildtarget=RELEASE,
+      the bios file path:  Build/LoongArchQemu/RELEASE_GCC5/FV/QEMU_EFI.fd
+
+(4) Build kernel:
+
+.. code-block:: bash
+
+  git clone https://github.com/loongson/linux.git
+
+  cd linux
+
+  git checkout loongarch-next
+
+  make ARCH=loongarch CROSS_COMPILE=loongarch64-unknown-linux-gnu- loongson3_defconfig
+
+  make ARCH=loongarch CROSS_COMPILE=loongarch64-unknown-linux-gnu- -j32
+
+Note: The branch of linux source code is loongarch-next.
+      the kernel file: arch/loongarch/boot/vmlinuz.efi
+
+(5) Get initrd:
+
+  You can use busybox tool and the linux modules to make a initrd file. Or you can access the
+  binary files: https://github.com/yangxiaojuan-loongson/qemu-binary
+
+.. code-block:: bash
+
+  git clone https://github.com/yangxiaojuan-loongson/qemu-binary
+
+Note: the initrd file is ramdisk
+
+(6) Booting LoongArch:
+
+.. code-block:: bash
+
+  $ ./build/qemu-system-loongarch64 -machine virt -m 4G -cpu la464 \
+      -smp 1 -bios QEMU_EFI.fd -kernel vmlinuz.efi -initrd ramdisk \
+      -serial stdio   -monitor telnet:localhost:4495,server,nowait \
+      -append "root=/dev/ram rdinit=/sbin/init console=ttyS0,115200" \
+      --nographic