Documentation: add notes about TAP configuration for qemu

add notes how to configure QEMU network with TAP.

Signed-off-by: raiden00pl <[email protected]>

Author: raiden00pl

Documentation/guides/index.rst

@@ -60,4 +60,5 @@ Guides
   remove_device_drivers_nsh.rst
   rust.rst
   optee.rst
+  qemu_tips.rst
 

Documentation/guides/qemu_tips.rst

@@ -0,0 +1,44 @@
+=========
+QEMU Tips
+=========
+
+Netowrking with TAP device
+==========================
+
+Step 1: Configure NuttX network with ``NETUTILS_NETINIT``::
+
+  CONFIG_NETUTILS_NETINIT=y
+  CONFIG_NETINIT_IPADDR=0xc0a80868   # Target: 192.168.8.104
+  CONFIG_NETINIT_DRIPADDR=0xc0a80801 # Router: 192.168.8.1
+  CONFIG_NETINIT_NETMASK=0xffffff00  # Mask:   255.255.255.0
+
+Step 2: Create and configure a TAP device on the host::
+
+  # Create the bridge
+  sudo ip link add name br0 type bridge
+  sudo ip link set br0 up
+
+  # Create the tap interface
+  sudo ip tuntap add dev tap0 mode tap
+  sudo ip link set tap0 master br0
+  sudo ip link set tap0 up
+
+  # (optional) also attach your real NIC if you want LAN access
+  # sudo ip link set enp3s0 master br0
+
+  # Assign IP to the *bridge*
+  sudo ip addr add 192.168.8.1/24 dev br0
+
+Step 3: Launch QEMU using the TAP interface::
+
+  qemu-system-x86_64 -m 2G -smp 4 -cpu host -enable-kvm \
+  -kernel nuttx -nographic -serial mon:stdio \
+  -device e1000,netdev=mynet0 \
+  -netdev tap,id=mynet0,ifname=tap0,script=no,downscript=no
+
+Step 4: Clean up::
+
+  sudo ip link set tap0 down
+  sudo ip link set br0 down
+  sudo ip tuntap del dev tap0 mode tap
+  sudo ip link del br0

Documentation/platforms/x86_64/intel64/boards/qemu-intel64/index.rst

@@ -5,8 +5,6 @@ qemu-intel64
 This page file describes the contents of the build configurations available
 for the NuttX QEMU x86_64 port.
 
-
-
 QEMU/KVM
 ========
 
@@ -187,6 +185,13 @@ Command to run the image with some xHCI devices attached::
   -kernel nuttx -serial mon:stdio -chardev pty,id=ch1 \
   -device qemu-xhci -device usb-mouse -device usb-kbd
 
+Command to run the image with e1000 NIC device with TAP::
+
+  qemu-system-x86_64 -m 2G -smp 4 -cpu host -enable-kvm \
+  -kernel nuttx -nographic -serial mon:stdio \
+  -device e1000,netdev=mynet0 \
+  -netdev tap,id=mynet0,ifname=tap0,script=no,downscript=no
+
 knsh_romfs
 ----------