How can Zephyr networking be implemented on boards that have Ethernet capability?

[bikeNomad]

I see that the default prj.conf has CONFIG_NETWORKING=y, and that the mpconfigport.h has MICROPY_PY_SOCKET defined.

I understand that the qemu_x86 port is useful for running the tests (and it has CONFIG_NET_SLIP_TAP=y). But other than this kind of serial network connection, is there any way that we could get networking on some other Zephyr board (like the nucleo_f429zi board that I have) that has Ethernet hardware (on the SOC and on the board)?

What purpose does MICROPY_PY_SOCKET have for those many boards/SOCs that don't have networking hardware (assuming that they're not running SLIP)?

Since Zephyr has its own network stack, we shouldn't use LWIP.

But the alternative seems to require MICROPY_PORT_NETWORK_INTERFACES to be defined, and defines network.country (what use is this for an Ethernet connection?).

This requires these methods to be implemented:

typedef struct _mod_network_nic_protocol_t {
    // API for non-socket operations
    int (*gethostbyname)(mp_obj_t nic, const char *name, mp_uint_t len, uint8_t *ip_out);
    void (*deinit)(void);

    // API for socket operations; return -1 on error
    int (*socket)(struct _mod_network_socket_obj_t *socket, int *_errno);
    void (*close)(struct _mod_network_socket_obj_t *socket);
    int (*bind)(struct _mod_network_socket_obj_t *socket, byte *ip, mp_uint_t port, int *_errno);
    int (*listen)(struct _mod_network_socket_obj_t *socket, mp_int_t backlog, int *_errno);
    int (*accept)(struct _mod_network_socket_obj_t *socket, struct _mod_network_socket_obj_t *socket2, byte *ip, mp_uint_t *port, int *_errno);
    int (*connect)(struct _mod_network_socket_obj_t *socket, byte *ip, mp_uint_t port, int *_errno);
    mp_uint_t (*send)(struct _mod_network_socket_obj_t *socket, const byte *buf, mp_uint_t len, int *_errno);
    mp_uint_t (*recv)(struct _mod_network_socket_obj_t *socket, byte *buf, mp_uint_t len, int *_errno);
    mp_uint_t (*sendto)(struct _mod_network_socket_obj_t *socket, const byte *buf, mp_uint_t len, byte *ip, mp_uint_t port, int *_errno);
    mp_uint_t (*recvfrom)(struct _mod_network_socket_obj_t *socket, byte *buf, mp_uint_t len, byte *ip, mp_uint_t *port, int *_errno);
    int (*setsockopt)(struct _mod_network_socket_obj_t *socket, mp_uint_t level, mp_uint_t opt, const void *optval, mp_uint_t optlen, int *_errno);
    int (*settimeout)(struct _mod_network_socket_obj_t *socket, mp_uint_t timeout_ms, int *_errno);
    int (*ioctl)(struct _mod_network_socket_obj_t *socket, mp_uint_t request, mp_uint_t arg, int *_errno);
} mod_network_nic_protocol_t;

And it requires calling mod_network_register_nic() on any network interfaces you want to use.

I think networking also requires MICROPY_PY_NETWORK_LAN to be defined.

The only support I can see for non-LWIP network interfaces seems to be for the NINAW10, ESP_HOSTED, MIMXRT, and the WIZNET5K.

The mimxrt port looks to be a good example (see ports/mimxrt/network_lan.c). This allows an mimxrt board to have networking using one of five PHY types.

I am also puzzled by the Micropython Zephyr port for the beagleconnect_freedom board that is configured like this (apparently for 802.15.4 over 900MHz radio):

# Networking
CONFIG_BT=n
CONFIG_NET_IPV4=n
CONFIG_NET_CONFIG_NEED_IPV6=y
CONFIG_NET_CONFIG_NEED_IPV4=n
CONFIG_NET_CONFIG_MY_IPV4_ADDR=""
CONFIG_NET_L2_IEEE802154=y
CONFIG_NET_DHCPV4=n
CONFIG_NET_CONFIG_IEEE802154_CHANNEL=1

How would this be used in practice?

[bikeNomad]

Well, I'm working on it with the help of Gemini CLI. I've got the network module almost finished but still can't get an outbound socket connection to work.

[ganboing]

User of micropython/zephyr here. To have ethernet networking, I think CONFIG_NET_L2_ETHERNET=y is all you need. At least on my olimex_stm32_e407 board (A very similar SoC compared to nucleo_f429zi), the network interface (MAC/PHY...) works out-of-the-box once it's defined.

[ganboing]

The zephyr debug network shell is also very helpful for debugging. I have the config to enable shell running as a telnet service:

# Shell
CONFIG_SHELL=y
CONFIG_SHELL_BACKEND_TELNET=y
CONFIG_SHELL_BACKEND_SERIAL=n

# Networking
CONFIG_NET_L2_ETHERNET=y
CONFIG_NET_SHELL=y

And I can connect to the shell to collect network related information:

~$ net iface

Default interface: 1


Interface eth0 (0x20002240) (Ethernet) [1]
===================================
Link addr : 00:80:E1:F5:D8:C0
MTU       : 1500
Flags     : AUTO_START,IPv4,IPv6
Device    : ethernet (0x805e680)
Status    : oper=UP, admin=UP, carrier=ON
Ethernet capabilities supported:
	10 Mbits
	100 Mbits
Ethernet PHY device: ethernet-phy@0 (0x805e65c)
Ethernet link speed: 100 Mbits full-duplex
IPv6 unicast addresses (max 2):
	fe80::280:e1ff:fef5:d8c0 autoconf preferred infinite
	2001:db8::1 manual preferred infinite
IPv6 multicast addresses (max 3):
	ff02::1
	ff02::1:fff5:d8c0
	ff02::1:ff00:1
IPv6 prefixes (max 2):
	<none>
IPv6 hop limit           : 64
IPv6 base reachable time : 30000
IPv6 reachable time      : 24528
IPv6 retransmit timer    : 0
IPv4 unicast addresses (max 1):
	192.168.122.18/255.255.255.0 DHCP preferred
IPv4 multicast addresses (max 2):
	224.0.0.1
IPv4 gateway : 0.0.0.0
DHCPv4 lease time : 3600
DHCPv4 renew time : 1687
DHCPv4 server     : 192.168.122.1
DHCPv4 requested  : 192.168.122.18
DHCPv4 state      : bound
DHCPv4 attempts   : 1
DHCPv4 state      : bound