With uClinux running on the i.MX RT1170, you get the full Linux TCP/IP stack (kernel version 4.5.0). Userspace POSIX APIs are provided by the uClibc library. Key user-space networking tools and utilities are available from the multi-call busybox. Additional tools and packages, such as for instance the SSH dropbear server, can be built specifically for uClinux. All in all, you have the powerful Linux TCP/IP stack at your disposal.
There is a full-functioning Ethernet device driver available in the kernel tree for the i.MX RT1170. The device driver is linux/drivers/net/ethernet/freescale/fec.c configured in the kernel using the CONFIG_FEC build time option in Device Drivers -> Network device support -> Ethernet driver support -> Freescale devices -> FEC ethernet controller (of ColdFire and some i.MX CPUs).
For the run-time configuration of the kernel, Ethernet is enabled in rootfs.dts.IMXRT117X_NXPEVK in projects/rootfs as follows:
&fec1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_fec1>, <&pinctrl_fec1_lpsr>;
status = "okay";
assigned-clocks = <&clks IMXRT1170_CLK_ROOT_ENET1>;
assigned-clock-parents = <&clks IMXRT1170_CLK_PLL1_DIV2>;
assigned-clock-rates = <50000000>;
fsl,ref-clk-dir = <&gpr 0x10 1 1>;
phy-mode = "rmii";
phy-handle = <ðphy0>;
phy-reset-duration = <1>;
phy-reset-gpios = <&gpio12 12 GPIO_ACTIVE_LOW>;
clocks = <&clks IMXRT1170_CLK_ROOT_BUS>, <&clks IMXRT1170_CLK_ROOT_BUS>,
<&clks IMXRT1170_CLK_ENET1>;
clock-names = "ipg", "ahb", "enet_clk_ref";
mdio {
#address-cells = <1>;
#size-cells = <0>;
ethphy0: ethernet-phy@0 {
reg = <2>;
clocks = <&clks IMXRT1170_CLK_ENET1>;
clock-names = "rmii-ref";
};
};
};
This will register a platform device for the i.MX RT1170 Ethernet controller with the Ethernet driver.
The Linux project provided by Emcraft in the distribution (refer to projects/rootfs) and installed on each shipping module and kit includes the TCP/IP stack and various network related capabilities. The following snapshot shows the full Linux bootsrap sequence from power-on to the Linux shell:
U-Boot SPL 2023.04 (Sep 01 2023 - 17:34:47 +0000)
Trying to boot from MMC1
U-Boot 2023.04 (Sep 01 2023 - 17:34:47 +0000)
Model: NXP imxrt1170-evk board
DRAM: 960 KiB (effective 64.9 MiB)
Core: 72 devices, 15 uclasses, devicetree: separate
MMC: FSL_SDHC: 0
Loading Environment from MMC... OK
In: serial@4007c000
Out: serial@4007c000
Err: serial@4007c000
Net: eth0: ethernet@40424000
Hit any key to stop autoboot: 0
8489874 bytes read in 756 ms (10.7 MiB/s)
## Booting kernel from Legacy Image at 80007fc0 ...
Image Name: Linux-6.1.22
Image Type: ARM Linux Multi-File Image (uncompressed)
Data Size: 8489810 Bytes = 8.1 MiB
Load Address: 80008000
Entry Point: 80008001
Contents:
Image 0: 8480224 Bytes = 8.1 MiB
Image 1: 9574 Bytes = 9.3 KiB
Verifying Checksum ... OK
## Flattened Device Tree from multi component Image at 80007FC0
Booting using the fdt at 0x8081e5ec
Working FDT set to 8081e5ec
Loading Multi-File Image
Loading Device Tree to 2032a000, end 2032f565 ... OK
Working FDT set to 2032a000
Starting kernel ...
Booting Linux on physical CPU 0x0
Linux version 6.1.22 (sasha@workbench.emcraft.com) (arm-none-eabi-gcc
(GNU Arm Embedded Toolchain 10.3-2021.10) 10.3.1 20210824 (release),
GNU ld (GNU Arm Embedded Toolchain 10.3-2021.10) 2.36.1.20210621) #2
Fri Sep 1 14:20:49 UTC 2023
CPU: ARMv7-M [411fc272] revision 2 (ARMv7M), cr=00000000
CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache
OF: fdt: Machine model: NXP IMXRT1170 EVK board
Reserved memory: created DMA memory pool at 0x83f00000, size 1 MiB
OF: reserved mem: initialized node dmapool@83f00000, compatible id
shared-dma-pool
Zone ranges:
Normal [mem 0x0000000080000000-0x0000000083ffffff]
Movable zone start for each node
Early memory node ranges
node 0: [mem 0x0000000080000000-0x0000000083efffff]
node 0: [mem 0x0000000083f00000-0x0000000083ffffff]
Initmem setup node 0 [mem 0x0000000080000000-0x0000000083ffffff]
Built 1 zonelists, mobility grouping on. Total pages: 16256
Kernel command line: ip=192.168.88.89:192.168.88.170:192.168.88.1:255.
255.255.0::eth0:off
Unknown kernel command line parameters "ip=192.168.88.89:192.168.88.170:
192.168.88.1:255.255.255.0::eth0:off", will be passed to user space.
Dentry cache hash table entries: 8192 (order: 3, 32768 bytes, linear)
Inode-cache hash table entries: 4096 (order: 2, 16384 bytes, linear)
mem auto-init: stack:off, heap alloc:off, heap free:off
Memory: 55504K/65536K available (3423K kernel code, 185K rwdata, 908K
rodata, 3556K init, 95K bss, 10032K reserved, 0K cma-reserved)
NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
Switching to timer-based delay loop, resolution 41ns
sched_clock: 32 bits at 24MHz, resolution 41ns, wraps every 89478484971ns
clocksource: mxc_timer1: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns:
79635851949 ns
Calibrating delay loop (skipped), value calculated using timer frequency.. 48.00
BogoMIPS (lpj=240000)
pid_max: default: 4096 minimum: 301
Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
devtmpfs: initialized
DMA: default coherent area is set
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns:
19112604462750000 ns
futex hash table entries: 16 (order: -5, 192 bytes, linear)
pinctrl core: initialized pinctrl subsystem
NET: Registered PF_NETLINK/PF_ROUTE protocol family
imxrt1170-pinctrl 400e8000.iomuxc: initialized IMX pinctrl driver
imxrt1170-pinctrl 40c08000.iomuxc_lpsr: initialized IMX pinctrl driver
imxrt1170-pinctrl 40c94000.iomuxc_snvs: initialized IMX pinctrl driver
SCSI subsystem initialized
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
pps_core: LinuxPPS API ver. 1 registered
pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti
<giometti@linux.it>
PTP clock support registered
Bluetooth: Core ver 2.22
NET: Registered PF_BLUETOOTH protocol family
Bluetooth: HCI device and connection manager initialized
Bluetooth: HCI socket layer initialized
Bluetooth: L2CAP socket layer initialized
Bluetooth: SCO socket layer initialized
clocksource: Switched to clocksource mxc_timer1
NET: Registered PF_INET protocol family
IP idents hash table entries: 2048 (order: 2, 16384 bytes, linear)
tcp_listen_portaddr_hash hash table entries: 1024 (order: 0, 4096 bytes, linear)
Table-perturb hash table entries: 65536 (order: 6, 262144 bytes, linear)
TCP established hash table entries: 1024 (order: 0, 4096 bytes, linear)
TCP bind hash table entries: 1024 (order: 1, 8192 bytes, linear)
TCP: Hash tables configured (established 1024 bind 1024)
UDP hash table entries: 256 (order: 0, 4096 bytes, linear)
UDP-Lite hash table entries: 256 (order: 0, 4096 bytes, linear)
NET: Registered PF_UNIX/PF_LOCAL protocol family
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
Bus freq driver module loaded
Initialise system trusted keyrings
workingset: timestamp_bits=30 max_order=14 bucket_order=0
fuse: init (API version 7.37)
Key type asymmetric registered
Asymmetric key parser 'x509' registered
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
io scheduler mq-deadline registered
io scheduler kyber registered
4007c000.serial: ttyLP0 at MMIO 0x4007c010 (irq = 447, base_baud = 1500000) is
a FSL_LPUART
fsl-lpuart 4007c000.serial: Serial: Console lpuart rounded baud ratefrom 187500 to
115200
printk: console [ttyLP0] enabled
PPP generic driver version 2.4.2
PPP BSD Compression module registered
PPP Deflate Compression module registered
usbcore: registered new interface driver rt2800usb
usbcore: registered new interface driver cdc_acm
cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
usbcore: registered new interface driver uas
usbcore: registered new interface driver usb-storage
i2c_dev: i2c /dev entries driver
usbcore: registered new interface driver btusb
sdhci: Secure Digital Host Controller Interface driver
sdhci: Copyright(c) Pierre Ossman
sdhci-pltfm: SDHCI platform and OF driver helper
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
NET: Registered PF_PACKET protocol family
mmc0 bounce up to 128 segments into one, max segment size 65536 bytes
Bluetooth: RFCOMM TTY layer initialized
Bluetooth: RFCOMM socket layer initialized
Bluetooth: RFCOMM ver 1.11
ARMv7-M VFP coprocessor found
VFP: Double precision floating points are supported
Loading compiled-in X.509 certificates
mmc0: SDHCI controller on 40418000.usdhc [40418000.usdhc] using DMA
input: gpio-keys as /devices/platform/gpio-keys/input/input0
cfg80211: Loading compiled-in X.509 certificates for regulatory database
cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
cfg80211: failed to load regulatory.db
Freeing unused kernel image (initmem) memory: 3556K
This architecture does not have kernel memory protection.
Run /init as init process
[72] Jan 01 00:00:01 Running in background
/ # mmc0: host does not support reading read-only switch, assuming write-enable
mmc0: new high speed SDHC card at address 59b4
mmcblk0: mmc0:59b4 USD 7.39 GiB
mmcblk0: p1
Micrel KSZ8081 or KSZ8091 40424000.ethernet-1:02: attached PHY driver
(mii_bus:phy_addr=40424000.ethernet-1:02, irq=POLL)
fec 40424000.ethernet eth0: Link is Up - 100Mbps/Full - flow control off
/ #
Let's test the TCP/IP stack on the i.MX RT1170.
From the development host validate that the i.MX RT1170 is visible using
ping:$ ping 192.168.88.89 -c 5 PING 192.168.88.89 (192.168.88.89) 56(84) bytes of data. 64 bytes from 192.168.88.89: icmp_seq=1 ttl=64 time=8.99 ms 64 bytes from 192.168.88.89: icmp_seq=2 ttl=64 time=1.93 ms 64 bytes from 192.168.88.89: icmp_seq=3 ttl=64 time=11.9 ms 64 bytes from 192.168.88.89: icmp_seq=4 ttl=64 time=1.75 ms 64 bytes from 192.168.88.89: icmp_seq=5 ttl=64 time=2.07 ms --- 192.168.88.89 ping statistics --- 5 packets transmitted, 5 received, 0% packet loss, time 405ms rtt min/avg/max/mdev = 1.746/5.323/11.877/4.272 ms
pingthe development host from the i.MX RT1170:/ # ping 192.168.88.170 -c 5 PING 192.168.88.170 (192.168.88.170): 56 data bytes 64 bytes from 192.168.88.170: seq=0 ttl=64 time=8.999 ms 64 bytes from 192.168.88.170: seq=1 ttl=64 time=3.367 ms 64 bytes from 192.168.88.170: seq=2 ttl=64 time=3.020 ms 64 bytes from 192.168.88.170: seq=3 ttl=64 time=2.845 ms 64 bytes from 192.168.88.170: seq=4 ttl=64 time=3.012 ms --- 192.168.88.170 ping statistics --- 5 packets transmitted, 5 packets received, 0% packet loss round-trip min/avg/max = 2.845/4.248/8.999 ms
On the target, start the
telnetddaemon to allow connections to the i.MX RT1170:/ # ps | grep telnetd 99 root 848 S telnetd 101 root 848 S grep telnetd / # / #
Connect to the target from the development host using telnet. The target is configured to accept the
123password for root.$ telnet 192.168.88.89 Trying 192.168.88.89... Connected to 192.168.88.89. Escape character is '^]'. (none) login: root Password: / # ls bin hello.ko lib proc sys var dev httpd linuxrc root tmp etc init mnt sbin usr / # exit Connection closed by foreign host. $
The
dropbearSSH daemon starts automatically on the target. Verify thatdropbearallows secure connections to the target:/ # ps | grep dropbear 72 root 728 S dropbear -R 99 root 864 S grep dropbear / #
Connect to the target from the development host using ssh. The first connection takes several seconds to establish as the i.MX RT1170 runs computation-extensive key calculations. Again, enter
123on the password prompt:$ ssh root@192.168.88.89 The authenticity of host '192.168.88.89 (192.168.88.89)' can't be established. ED25519 key fingerprint is SHA256:i2ePwYaIvztXXdWDoDXrOWhdYMB87xX9V5T1pZEIxGM. This key is not known by any other names Are you sure you want to continue connecting (yes/no/[fingerprint])? yes Warning: Permanently added '192.168.88.89' (ED25519) to the list of known hosts. root@192.168.88.89's password: / # ls bin hello.ko lib proc sys var dev httpd linuxrc root tmp etc init mnt sbin usr / # exit Connection to 192.168.88.89 closed by remote host. Connection to 192.168.88.89 closed. $
On the target, enable access to the Internet by configuring a default gateway. Note also that the system makes use of the public name server provided by Google:
/ # route add default gw 192.168.88.1 / # cat /etc/resolv.conf # This configuration makes use of the Google public DNS server. # If you would like to use something else, replace with the IP # of your DNS server nameserver 8.8.8.8 / #
Use
ntpdto synchronize the time on the target with the time provided by a public server:/ # date Thu Jan 1 00:09:27 UTC 1970 / # ntpd -p http://0.fedora.pool.ntp.org / # sleep 5 / # date Mon Aug 21 07:13:18 UTC 2023
Use
wgetto download a file from a remote server:/ # wget ftp://ftp.gnu.org/README Connecting to http://ftp.gnu.org (209.51.188.20:21) saving to 'README' README 100% |********************************| 2748 0:00:00 ETA 'README' saved / # cat README This is http://ftp.gnu.org , the FTP server of the the GNU project. ...
Mount a directory exported by a development host over NFS:
/ # mount -o nolock,rsize=1024 192.168.1.99:/srv/nfs /mnt/nfs / # ls /mnt/nfs/ SimpleClass linux-dp test / # cp /bin/busybox /mnt/nfs / # cp /mnt/nfs/busybox /tmp / # md5sum /bin/busybox /tmp/busybox bb39cf3470150200a35c41bd6f78ef92 /bin/busybox bb39cf3470150200a35c41bd6f78ef92 /tmp/busybox