@ -1,166 +1,372 @@
# Emulating MPS2 Cortex M3 AN385 on QEMU
# TCP Echo Client Demo for MPS2 Cortex-M3 AN385 emulated using QEMU
This FreeRTOS+TCP example demonstrates a TCP Echo Client which sends
echo requests to an Echo Server and then receives the echo reply. The
Echo Client runs on the MPS2 Cortex-M3 AN385 platform emulated using QEMU.
## Requirements
1. GNU Arm Embedded Toolchain download [here ](https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-rm/downloads )
3. qemu-arm-system download [here ](https://www.qemu.org/download )
2. Make (tested on version 3.82)
4. Linux OS (tested on Ubuntu 18.04)
## Setup Description
The demo requires 2 components -
1. Echo Client - The demo in this repository.
1. Echo Server - An external echo server.
## How to download
Navigate to a parent directory of your choice and run the following command
We need a Virtual Machine (VM) running Linux OS to run this demo. Echo Client
runs in the Virtual Machine (VM) and Echo Server runs on the host machine.
```
$ git clone https://github.com/FreeRTOS/FreeRTOS.git --recurse-submodules --depth 1
+--------------------------------------------------------+
| Host Machine |
| OS - Any |
| Runs - Echo Server |
| +--------------------------+ |
| | Virtual Machine (VM) | |
| | OS - Linux | |
| | Runs - Echo Client | |
| | | |
| +----------------+ | +----------------+ | |
| | | | | | | |
| | | | | | | |
| | Echo Server | < ------- > | Echo Client | | |
| | | | | | | |
| | | | | | | |
| | | | | | | |
| +----------------+ | +----------------+ | |
| | | |
| +--------------------------+ |
+--------------------------------------------------------+
```
The previous command should create a directory named **FreeRTOS**
## Networking Echo client Demo
To make networking support possible a few steps needs to be done on the machine
lets assume the following interfaces using ubuntu 18.04 or Fedora 30
(the interface names on your machine could be different)
## Setting up VM
1. Install a Virtual Machine software on your machine. On Windows you can use
[Oracle VirtualBox ](https://www.virtualbox.org/ ) and on Mac you can use
[Parallels ](https://www.parallels.com/products/desktop/ ).
2. Launch a Linux VM. We tested using Ubuntu 22.04.
3. Install the following tools in the VM:
* [GNU Arm Embedded Toolchain ](https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-rm/downloads ).
* [qemu-arm-system ](https://www.qemu.org/download ).
* Make (Version 4.3):
```
sudo apt install make
```
* ipcalc:
```
sudo apt install ipcalc
```
* brctl:
```
sudo apt install bridge-utils
```
4. Clone the source code in the VM:
```shell
git clone https://github.com/FreeRTOS/FreeRTOS.git --recurse-submodules --depth 1
```
## Launch Echo Server
Launch Echo Server on the host machine.
### Host OS is Linux
* Install `netcat` :
```
sudo apt install netcat
```
* Start an Echo Server on port 7:
```shell
sudo nc -l 7
```
### Host OS is Windows
* Install [Npcap/Nmap ](https://nmap.org/download.html#windows ).
* Start an Echo Server on port 7:
```shell
ncat -l 7
```
### Host OS is Mac
* Install `netcat` :
```shell
brew install netcat
```
* Start an Echo Server on port 7:
```shell
nc -l -p 7
```
## Enable Networking in QEMU
The Echo Client in this demo runs in QEMU inside the VM. We need to enable
networking in QEMU to enable the Echo Client to be able to reach the Echo
Server. Do the following steps in the VM:
1. Run the `ifconfig` command to find the VM's network interface details:
```
enp0s3: flags=4163< UP , BROADCAST , RUNNING , MULTICAST > mtu 9001
inet 192.168.1.81 netmask 255.255.255.0 broadcast 192.168.15.255
inet6 fe80::89c:55ff:fe3d:18ad prefixlen 64 scopeid 0x20< link >
ether 0a:9c:55:3d:18:ad txqueuelen 1000 (Ethernet)
RX packets 15001255 bytes 11443805826 (11.4 GB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 9248218 bytes 2080385000 (2.0 GB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
```
2. Define a shell variable `VM_NETWORK_INTERFACE` and set its value to the
name of the network interface of the VM. For example, in the above output
of the `ifconfig` command, name of the the network interface is `enp0s3` :
```shell
export VM_NETWORK_INTERFACE=enp0s3
```
3. Define a shell variable `VM_IP_ADDRESS` and set its value to the IP address
of the VM. For example, in the above output of the `ifconfig` command, IP
address of the VM is `192.168.1.81` :
```shell
export VM_IP_ADDRESS=192.168.1.81
```
4. Define a shell variable `VM_NETMASK` and set its value to the netmask of
the VM. For example, in the above output of the `ifconfig` command, netmask
of the VM is `255.255.255.0` :
```shell
export VM_NETMASK=255.255.255.0
```
5. Calculate the CIDR of the VM from the netmask:
```shell
$ ipcalc -b 1.1.1.1 $VM_NETMASK | grep Netmask
Netmask: 255.255.255.0 = 24
```
CIDR is `24` in the above output.
6. Define a shell variable `VM_CIDR` and set its value to the CIDR of the VM
found in the above step.
```shell
export VM_CIDR=24
```
7. Find the Default Gateway for the VM:
```shell
$ ip route show
default via 192.168.1.254 dev enp0s3 proto dhcp src 192.168.1.81 metric 100
```
Default Gateway is `192.168.1.254` in the above output.
8. Define a shell variable `VM_DEFAULT_GATEWAY` and set its value to the
Default Gateway of the VM found in the above step.
```shell
export VM_DEFAULT_GATEWAY=192.168.1.254
```
9. Find the DNS Server of the VM:
```shell
$ grep "nameserver" /etc/resolv.conf
nameserver 192.168.1.254
```
10. Define a shell variable `VM_DNS_SERVER` and set its value to the
DNS Server of the host machine found in the above step.
```shell
export VM_DNS_SERVER=192.168.1.254
```
l0: loopback in terface
enp0s3: ethernet interface
virbr0: virtual bridge (to be created)
virbr0-nic: veth virtual interface (to be created)
11. Pick an IP address for the QEMU which is in the same network as the VM.
This IP address must not be in-use by any other machine on the same network.
Define a shell variable `QEMU_IP_ADDRESS` and set its value to the
picked IP Address. For example, run the following command if you picked
`192.168.1.80` :
```shell
export QEMU_IP_ADDRESS=192.168.1.80
```
### A few assumptions (your numbers could vary)
12. Pick a MAC address for the QEMU. Define a shell variable `QEMU_MAC_ADDRESS`
and set its value to the picked MAC Address. For example, run the following
command if you picked `52:54:00:12:34:AD` :
```shell
export QEMU_MAC_ADDRESS=52:54:00:12:34:AD
```
Local Host IP address: 192.168.1.81
Local FreeRTOS IP address: 192.168.1.80
Local FreeRTOS Subnet mask: 255.255.255.0
Default Gateway IP address: 192.168.1.254
Default DNS IP address: 192.168.1.254
Echo Server IP address: 192.168.1.204
Echo Server Port: 7
Local FreeRTOS Mac address: 52:54:00:12:34:AD
13. Define a shell variable `ECHO_SERVER_IP_ADDRESS` and set its value to the
IP address of the Echo Server which is running on the host. For example,
run the following command if the IP address of the Echo Server is
`192.168.1.204` :
```shell
export ECHO_SERVER_IP_ADDRESS=192.168.1.204
```
14. Turn off firewall on the VM.
On Ubuntu run:
```shell
sudo ufw disable
sudo ufw status
```
On RedHat/Fedora system run:
```shell
sudo systemctl status firewalld
sudo systemctl stop firewalld
```
15. Create virtual bridge (virbr0) and virtual NIC (virbr0-nic) to enable
networking in QEMU.
```shell
sudo ip link add virbr0 type bridge
sudo ip tuntap add dev virbr0-nic mode tap
### Building and Running
sudo ip addr add $VM_IP_ADDRESS/$VM_CIDR dev virbr0
1. Fill the defines values in FreeRTOSConfig.h with what is equivalent to the
above values on your system
sudo brctl addif virbr0 $VM_NETWORK_INTERFACE
sudo brctl addif virbr0 virbr0-nic
sudo ip link set virbr0 up
sudo ip link set virbr0-nic up
sudo ip route add default via $VM_DEFAULT_GATEWAY dev virbr0
```
The following diagram shows the setup:
```
+-------------------------------------------------------------------------+
| Virtual Machine (VM) |
| |
| +-------------------------+ | VM NIC (enp0s3)
| | | Virtual NIC (virbr0-nic) +--+
| | QEMU +--+ | |
| | | | +--------------+ | |
| | | +--------->| virbr0 | ---------->| +--------> Internet
| | | | +--------------+ | |
| | +--+ Virtual Bridge | |
| | | +--+
| +-------------------------+ |
| |
| |
+-------------------------------------------------------------------------+
```
## Build and Run
Do the following steps in the VM where you cloned the code:
1. Set `configIP_ADDR0` -`configIP_ADDR3` in `FreeRTOSConfig.h` to the value
of `QEMU_IP_ADDRESS` :
```shell
echo $QEMU_IP_ADDRESS
```
```c
#define configIP_ADDR0 192
#define configIP_ADDR1 168
#define configIP_ADDR2 1
#define configIP_ADDR3 80
```
2. Set `configNET_MASK0` -`configNET_MASK3` in `FreeRTOSConfig.h` to the value
of `VM_NETMASK` :
```shell
echo $VM_NETMASK
```
```c
#define configNET_MASK0 255
#define configNET_MASK1 255
#define configNET_MASK2 255
#define configNET_MASK3 0
```
3. Set `configGATEWAY_ADDR0` -`configGATEWAY_ADDR3` in `FreeRTOSConfig.h` to
the value of `VM_DEFAULT_GATEWAY` :
```shell
echo $VM_DEFAULT_GATEWAY
```
```c
#define configGATEWAY_ADDR0 192
#define configGATEWAY_ADDR1 168
#define configGATEWAY_ADDR2 1
#define configGATEWAY_ADDR3 254
```
4. Set `configDNS_SERVER_ADDR0` -`configDNS_SERVER_ADDR3` in `FreeRTOSConfig.h`
to the value of `VM_DNS_SERVER` :
```shell
echo $VM_DNS_SERVER
```
```c
#define configDNS_SERVER_ADDR0 192
#define configDNS_SERVER_ADDR1 168
#define configDNS_SERVER_ADDR2 1
#define configDNS_SERVER_ADDR3 254
```
5. Set `configMAC_ADDR0` -`configMAC_ADDR5` in `FreeRTOSConfig.h` to the value
of `QEMU_MAC_ADDRESS` :
```shell
echo $QEMU_MAC_ADDRESS
```
```c
#define configMAC_ADDR0 0x52
#define configMAC_ADDR1 0x54
#define configMAC_ADDR2 0x00
#define configMAC_ADDR3 0x12
#define configMAC_ADDR4 0x34
#define configMAC_ADDR5 0xAD
```
6. Set `configECHO_SERVER_ADDR0` -`configECHO_SERVER_ADDR3` in `FreeRTOSConfig.h`
to the value of `ECHO_SERVER_IP_ADDRESS` :
```shell
echo $ECHO_SERVER_IP_ADDRESS
```
```c
#define configECHO_SERVER_ADDR0 192
#define configECHO_SERVER_ADDR1 168
#define configECHO_SERVER_ADDR2 1
#define configECHO_SERVER_ADDR3 204
```
2. Build your software
```
$ make
```
options: DEBUG=1 to build with ** -O0** and debugging symbols
3. On the remote machine (ip 192.168.1.204)
```
$ sudo nc -l 7
```
4. Turn off the firewall if running
On RedHat/Fedora system (tested Fedora 30) run:
```
sudo systemctl status firewalld
sudo systemctl stop firewalld
```
On Ubuntu run:
```
$ sudo ufw disable
$ sudo ufw status
```
5. Setup the local machine
Run the following commands replacing the values and interface names
that conform to your system
```
sudo ip link add virbr0 type bridge
sudo ip tuntap add dev virbr0-nic mode tap
sudo ip addr add 192.168.1.81/24 dev virbr0
sudo brctl addif virbr0 enp0s3
sudo brctl addif virbr0 virbr0-nic
sudo ip link set virbr0 up
sudo ip link set virbr0-nic up
sudo ip route add default via 192.168.1.254 dev virbr0
7. Build:
```shell
make
```
6. Run the demo
```
$ sudo qemu-system-arm -machine mps2-an385 -cpu cortex-m3
-kernel ./build/RTOSDemo.axf \
8. Run:
```shell
sudo qemu-system-arm -machine mps2-an385 -cpu cortex-m3 \
-kernel ./build/freertos_tcp_mps2_demo.axf \
-netdev tap,id=mynet0,ifname=virbr0-nic,script=no \
-net nic,macaddr=52:54:00:12:34:AD,model=lan9118,netdev=mynet0 \
-net nic,macaddr=$QEMU_MAC_ADDRESS,model=lan9118,netdev=mynet0 \
-object filter-dump,id=tap_dump,netdev=mynet0,file=/tmp/qemu_tap_dump\
-display gtk -m 16M -nographic -serial stdio \
-monitor null -semihosting -semihosting-config enable=on,target=native
```
Replace the value of macaddr=52:54:00:12:34:AD with your own value from
```
configMAC_ADDR0 through configMAC_ADDR5
```
7. Expectations
On the remote machine you should expect to see something similar to the
following:
9. You should see that following output on the terminal of the Echo Server (which
is running `sudo nc -l 7` or `netcat -l 7` depending on your OS):
```
$ sudo nc -l 7
Password:
TxRx message number
0FGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~0123456789:;< => ?
@ABCDEFGHIJKLMNOPQRSTUVWXYZ [\]^_`abcdefghijklmnopqrstuvwxyz{|}~0123456789:;< =>?
@ABCDEFGHIJKLMNOPQRSTUVWXYZ [\]^_`abcdefghijklmnopqrstuvwxyz{|}~0123456789:;< =>?
@ABCDEFGHIJKLM
```
## How to start debugging
1. gdb
< P >
Append the -s and -S switches to the previous command (qemu-system-arm)< br >
-s: allow gdb to be attached to the process remotely at port 1234 < br >
-S: start the program in the paused state < br >
## Debug
1. Build with debugging symbols:
```
make DEBUG=1
```
run: (make sure you build the debug version)
2. Start QEMU in the paused state waiting for GDB connection:
```shell
sudo qemu-system-arm -machine mps2-an385 -cpu cortex-m3 -s -S \
-kernel ./build/freertos_tcp_mps2_demo.axf \
-netdev tap,id=mynet0,ifname=virbr0-nic,script=no \
-net nic,macaddr=$QEMU_MAC_ADDRESS,model=lan9118,netdev=mynet0 \
-object filter-dump,id=tap_dump,netdev=mynet0,file=/tmp/qemu_tap_dump\
-display gtk -m 16M -nographic -serial stdio \
-monitor null -semihosting -semihosting-config enable=on,target=native
```
$ arm-none-eabi-gdb -q ./build/RTOSDemo.axf
3. Run GDB:
```shell
$ arm-none-eabi-gdb -q ./build/freertos_tcp_mps2_demo.axf
(gdb) target remote :1234
(gdb) break main
(gdb) c
```
2. tcpdump
To monitor packets received to qemu running the qemu command (qemu-system-arm)
shown above will create a network packet dump that you could inspect with
```
$ sudo tcpdump -r /tmp/qemu_tap_dump | less
4. The above QEMU command creates a network packet dump in the file
`/tmp/qemu_tap_dump` which you can examine using `tcpdump` or WireShark:
```shell
sudo tcpdump -r /tmp/qemu_tap_dump | less
```
kar-rahul-aws
2 years ago
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