ThreadX + NetX Duo TCP echo demo for EK-RA8D2. More...

#include <stdint.h>
#include <string.h>
#include "ra8_board_ek_ra8d2.h"
#include "ra8_boot_entry.h"
#include "ra8_cgc.h"
#include "ra8_err.h"
#include "ra8_eth.h"
#include "ra8_isr.h"
#include "ra8_time.h"
#include "nx_api.h"
#include "nx_ether_driver_ra8_eth.h"
#include "tx_api.h"

Include dependency graph for main.c:

Enumerations
enum	demo_config_t : uint32_t { k_demo_baud = 115200U , k_demo_thread_stack = 8192U , k_demo_ip_thread_pri = 1U , k_demo_app_thread_pri = 8U , k_demo_packet_size = 1568U , k_demo_packet_count = 16U , k_demo_pool_bytes = 32768U , k_demo_ip_stack = 4096U , k_demo_arp_cache = 1024U , k_demo_echo_port = 7U , k_demo_recv_window = 4096U , k_demo_socket_ttl = 64U , k_demo_recv_timeout = 0xFFFFFFFFU , k_demo_log_buf_bytes = 80U }
	Compile-time settings for the NetX Duo TCP-echo demo. More...
enum	demo_ip_octet_t : uint8_t { k_demo_ip_oct_a = 0U , k_demo_ip_oct_b = 1U , k_demo_ip_oct_c = 2U , k_demo_ip_oct_d = 3U }
	Octet indices into a packed IPv4 address. More...
enum	demo_ip_shift_t : uint8_t { k_demo_ip_shift_a = 24U , k_demo_ip_shift_b = 16U , k_demo_ip_shift_c = 8U , k_demo_ip_shift_d = 0U }
	Bit shifts that pack a 4-octet IPv4 into NetX's ULONG. More...
enum	demo_mac_word_shift_t : uint8_t { k_demo_mac_msw_shift_b0 = 8U , k_demo_mac_msw_shift_b1 = 0U , k_demo_mac_lsw_shift_b2 = 24U , k_demo_mac_lsw_shift_b3 = 16U , k_demo_mac_lsw_shift_b4 = 8U , k_demo_mac_lsw_shift_b5 = 0U }
	Shifts that pack the 6-byte MAC into msw/lsw ULONG pairs. More...
enum	demo_decimal_t : uint8_t { k_demo_decimal_base = 10U }
	Constants used by the tiny base-10 byte-to-ASCII helper. More...
enum	demo_ipv4_t : uint16_t { k_demo_ipaddr_0 = 192U , k_demo_ipaddr_1 = 168U , k_demo_ipaddr_2 = 1U , k_demo_ipaddr_3 = 42U , k_demo_netmask_b = 255U , k_demo_octet_mask = 0xFFU }
	Demo IPv4 address + netmask octets and helper masks. More...
enum	demo_mac_idx_t : uint8_t { k_demo_mac_idx_0 = 0U , k_demo_mac_idx_1 = 1U , k_demo_mac_idx_2 = 2U , k_demo_mac_idx_3 = 3U , k_demo_mac_idx_4 = 4U , k_demo_mac_idx_5 = 5U }
	MAC-address byte indices. More...

Functions
static void	demo_panic_halt (void)
	Halt forever in WFI.
static void	demo_setup_or_halt (void)
	Bring CGC + the J-Link OB VCOM console + on-board Ethernet up.
static void	demo_print (const char *s)
	Convenience wrapper to write a NUL-terminated string to SCI8.
static char *	demo_append_byte (char *buf, uint8_t v)
	Append a single decimal byte to the staging buffer.
static ULONG	demo_pack_ip (const uint8_t *octets)
	Pack a 4-octet IPv4 array into NetX's host-order ULONG.
static void	demo_pack_mac (ULONG msw, ULONG lsw)
	Pack the local MAC into the msw/lsw fields NetX expects.
static void	demo_log_echo (ULONG n, ULONG peer_ip)
	Log "echoed N bytes from a.b.c.d" to SCI8.
static UINT	demo_netx_create_ip (void)
	Creates the NetX packet pool and IP instance with our MAC.
static UINT	demo_netx_bring_up (void)
static void	demo_echo_loop (void)
	Echo loop: accept -> recv -> send -> disconnect -> relisten.
static void	demo_thread_entry (ULONG thread_input)
	ThreadX worker entry: bring NetX up, then run the echo loop.
void	tx_application_define (void *first_unused_memory)
	ThreadX system-define hook: build worker thread + NetX core.
void	main (void)
	Application entry.

Variables
static const uint8_t	k_demo_mac [6] = {0x02U, 0x00U, 0x00U, 0x00U, 0x00U, 0x01U}
static const uint8_t	k_demo_ip [4]
	IPv4 address: 192.168.1.42 / 255.255.255.0.
static const uint8_t	k_demo_mask [4] = {k_demo_netmask_b, k_demo_netmask_b, k_demo_netmask_b, 0U}
	Subnet mask: 255.255.255.0.
static NX_PACKET_POOL	s_packet_pool
static NX_IP	s_ip
static NX_TCP_SOCKET	s_echo_socket
static UCHAR	s_pool_memory [k_demo_pool_bytes]
static ULONG	s_ip_stack [k_demo_ip_stack/sizeof(ULONG)]
static ULONG	s_arp_cache [k_demo_arp_cache/sizeof(ULONG)]
static TX_THREAD	s_demo_thread
static UCHAR	s_demo_stack [k_demo_thread_stack]

Detailed Description

ThreadX + NetX Duo TCP echo demo for EK-RA8D2.

Tag: [Ring 6 / APP] {World: S}

Brings the chip up the same way uart_hello does (CGC -> SCI8 @ 115200 8N1) and then hands control to ThreadX. The ThreadX application-define hook configures NetX Duo on top of our hardware Ethernet driver shim (nx_ether_driver_ra8_eth):

nx_system_initialize().
nx_packet_pool_create against a static byte pool.
nx_ip_create at static IP 192.168.1.42 / 255.255.255.0, passing nx_ether_driver_ra8_eth as the link driver.
nx_ip_address_change_notify is omitted – we never DHCP.
nx_arp_enable + nx_tcp_enable + nx_icmp_enable.
nx_tcp_socket_create + nx_tcp_server_socket_listen on port 7 (the IANA echo protocol).

The single worker thread loops:

nx_tcp_server_socket_accept (blocking).
nx_tcp_socket_receive -> nx_tcp_socket_send echo.
On peer close, nx_tcp_socket_disconnect + nx_tcp_server_socket_unaccept + nx_tcp_server_socket_relisten and back to accept.

Each accepted byte is logged to SCI8 as "echoed N bytes from a.b.c.d\r\n" so the J-Link OB CDC port gives visible feedback. NetX Duo is now the only TCP/IP stack in the tree – the hand-rolled ra8_net adapter and its companion ethernet_tcp_echo / ethernet_udp_echo / ethernet_http_responder apps were retired in #7.

Author: Brighton Sikarskie

Date: 2026-04-29

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: 0.1.0

Definition in file main.c.

Enumeration Type Documentation

◆ demo_config_t

enum demo_config_t : uint32_t

Compile-time settings for the NetX Duo TCP-echo demo.

Every numeric used during bring-up appears here so the magic- number lint never sees a bare integer. The SCI8 channel matches the on-board J-Link OB CDC bridge pins (PD_02 / PD_03). The pool sizing follows the standard NetX Duo demo recipe (16 packets at 1568 bytes each; pool overhead allowed for) which fits easily in the 2 MiB SRAM budget.

Note: k_demo_pool_bytes used to be pinned here with a warning not to grow it, because growing it to 98304 moved s_tx_pool_storage to 0x2201CA60 and from that address the Ethernet TX path corrupted bits 4 and 5 of every byte at a frame offset congruent to 13 (mod 16) – silently, under a valid FCS, so even the 60-byte ARP reply went out with the wrong sender IP and the board simply vanished off the wire (#499). That was never an Ethernet defect. SRAMWTSC.WTEN was never programmed, so every SRAM read ran with no wait state at ICLK = 250 MHz, which HUM Ch 58.3.7 p 3540 puts outside guaranteed operation; the GWCA's DMA reads of this pool were simply where it showed. ra8_cgc_init now programs it, and the 98304-byte layout was re-tested on the wire at 3/3 byte-exact after the fix (3/3 corrupt before it, same source, same board). The pool size is back to being an ordinary sizing choice.

Enumerator
k_demo_baud	Demo baud.
k_demo_thread_stack	Demo thread stack.
k_demo_ip_thread_pri	Demo IP thread priority.
k_demo_app_thread_pri	Demo app thread priority.
k_demo_packet_size	Demo packet size.
k_demo_packet_count	Demo packet count.
k_demo_pool_bytes	Packet pool (16 x 1568 + overhead).
k_demo_ip_stack	Demo IP stack.
k_demo_arp_cache	Demo arp cache.
k_demo_echo_port	Demo echo port.
k_demo_recv_window	Demo recv window.
k_demo_socket_ttl	Demo socket ttl.
k_demo_recv_timeout	TX_WAIT_FOREVER on this port.
k_demo_log_buf_bytes	Demo log buffer bytes.

Definition at line 87 of file main.c.

◆ demo_decimal_t

enum demo_decimal_t : uint8_t

Constants used by the tiny base-10 byte-to-ASCII helper.

Enumerator
k_demo_decimal_base	Base used by demo_append_byte.

Definition at line 143 of file main.c.

◆ demo_ip_octet_t

enum demo_ip_octet_t : uint8_t

Octet indices into a packed IPv4 address.

Enumerator
k_demo_ip_oct_a	Demo IP oct a.
k_demo_ip_oct_b	Demo IP oct b.
k_demo_ip_oct_c	Demo IP oct c.
k_demo_ip_oct_d	Demo IP oct d.

Definition at line 108 of file main.c.

◆ demo_ip_shift_t

enum demo_ip_shift_t : uint8_t

Bit shifts that pack a 4-octet IPv4 into NetX's ULONG.

Enumerator
k_demo_ip_shift_a	Demo IP shift a.
k_demo_ip_shift_b	Demo IP shift b.
k_demo_ip_shift_c	Demo IP shift c.
k_demo_ip_shift_d	Demo IP shift d.

Definition at line 119 of file main.c.

◆ demo_ipv4_t

enum demo_ipv4_t : uint16_t

Demo IPv4 address + netmask octets and helper masks.

Enumerator
k_demo_ipaddr_0	192.168.1.42
k_demo_ipaddr_1	Demo ipaddr 1.
k_demo_ipaddr_2	Demo ipaddr 2.
k_demo_ipaddr_3	Demo ipaddr 3.
k_demo_netmask_b	255.255.255.0 (first three octets).
k_demo_octet_mask	Mask one octet out of a packed IPv4.

Definition at line 148 of file main.c.

◆ demo_mac_idx_t

enum demo_mac_idx_t : uint8_t

MAC-address byte indices.

Enumerator
k_demo_mac_idx_0	Demo MAC index 0.
k_demo_mac_idx_1	Demo MAC index 1.
k_demo_mac_idx_2	Demo MAC index 2.
k_demo_mac_idx_3	Demo MAC index 3.
k_demo_mac_idx_4	Demo MAC index 4.
k_demo_mac_idx_5	Demo MAC index 5.

Definition at line 158 of file main.c.

◆ demo_mac_word_shift_t

enum demo_mac_word_shift_t : uint8_t

Shifts that pack the 6-byte MAC into msw/lsw ULONG pairs.

Enumerator
k_demo_mac_msw_shift_b0	Demo MAC msw shift b0.
k_demo_mac_msw_shift_b1	Demo MAC msw shift b1.
k_demo_mac_lsw_shift_b2	Demo MAC lsw shift b2.
k_demo_mac_lsw_shift_b3	Demo MAC lsw shift b3.
k_demo_mac_lsw_shift_b4	Demo MAC lsw shift b4.
k_demo_mac_lsw_shift_b5	Demo MAC lsw shift b5.

Definition at line 130 of file main.c.

Function Documentation

◆ demo_append_byte()

char * demo_append_byte	(	char *	buf,
		uint8_t	v )

static

Append a single decimal byte to the staging buffer.

Parameters

[in,out]	buf	Buffer pointer (advanced past the appended digits).
[in]	v	Byte value (0..255).

Returns: Updated buffer pointer.

Precondition: buf != NULL with at least 4 bytes of headroom.

Since: 0.1.0

Definition at line 269 of file main.c.

References k_demo_decimal_base.

Referenced by demo_log_echo().

◆ demo_echo_loop()

void demo_echo_loop ( void )

static

Echo loop: accept -> recv -> send -> disconnect -> relisten.

Precondition: demo_netx_bring_up returned NX_SUCCESS.

Postcondition: Loop runs forever; never returns.

Since: 0.1.0

Definition at line 506 of file main.c.

References demo_log_echo(), demo_print(), k_demo_echo_port, s_echo_socket, and s_ip.

Referenced by demo_thread_entry().

◆ demo_log_echo()

void demo_log_echo	(	ULONG	n,
		ULONG	peer_ip )

static

Log "echoed N bytes from a.b.c.d" to SCI8.

Parameters

[in]	n	Number of bytes echoed.
[in]	peer_ip	Peer's IPv4 address as a host-order ULONG.

Since: 0.1.0

Definition at line 336 of file main.c.

References demo_append_byte(), demo_print(), k_demo_decimal_base, k_demo_ip_shift_a, k_demo_ip_shift_b, k_demo_ip_shift_c, k_demo_ip_shift_d, k_demo_log_buf_bytes, and k_demo_octet_mask.

Referenced by demo_echo_loop().

◆ demo_netx_bring_up()

UINT demo_netx_bring_up ( void )

static

Definition at line 451 of file main.c.

References demo_netx_create_ip(), k_demo_echo_port, k_demo_packet_count, k_demo_recv_window, k_demo_socket_ttl, s_arp_cache, s_echo_socket, s_ip, and s_socket_name.

◆ demo_netx_create_ip()

UINT demo_netx_create_ip ( void )

static

Creates the NetX packet pool and IP instance with our MAC.

Returns: UINT NX_SUCCESS on success, propagated NetX error otherwise.

Return values

NX_SUCCESS Pool and IP created; MAC pushed to link driver.

Precondition: nx_system_initialize has run.; File-scope s_packet_pool / s_ip are reserved.

Postcondition: On success, IP thread is running and link driver knows the MAC.; On failure, returned code names the failing API.

Note: Called once from demo_netx_bring_up.

Since: 0.1.0

Definition at line 406 of file main.c.

References demo_pack_ip(), demo_pack_mac(), k_demo_ip, k_demo_ip_thread_pri, k_demo_mac, k_demo_mask, k_demo_packet_size, nx_ether_driver_ra8_eth(), nx_ether_driver_ra8_eth_set_mac(), s_ip, s_ip_name, s_ip_stack, s_packet_pool, s_packet_pool_name, and s_pool_memory.

Referenced by demo_netx_bring_up().

◆ demo_pack_ip()

ULONG demo_pack_ip ( const uint8_t * octets )

static

Pack a 4-octet IPv4 array into NetX's host-order ULONG.

Parameters

[in] octets IPv4 address (4 bytes).

Returns: Host-order packed address suitable for nx_ip_interface_address_set.

Since: 0.1.0

Definition at line 302 of file main.c.

References k_demo_ip_oct_a, k_demo_ip_oct_b, k_demo_ip_oct_c, k_demo_ip_oct_d, k_demo_ip_shift_a, k_demo_ip_shift_b, k_demo_ip_shift_c, and k_demo_ip_shift_d.

◆ demo_pack_mac()

void demo_pack_mac	(	ULONG *	msw,
		ULONG *	lsw )

static

Pack the local MAC into the msw/lsw fields NetX expects.

Parameters

[out]	msw	Most-significant word (octets 0-1).
[out]	lsw	Least-significant word (octets 2-5).

Since: 0.1.0

Definition at line 318 of file main.c.

References k_demo_mac, k_demo_mac_idx_0, k_demo_mac_idx_1, k_demo_mac_idx_2, k_demo_mac_idx_3, k_demo_mac_idx_4, k_demo_mac_idx_5, k_demo_mac_lsw_shift_b2, k_demo_mac_lsw_shift_b3, k_demo_mac_lsw_shift_b4, k_demo_mac_lsw_shift_b5, k_demo_mac_msw_shift_b0, and k_demo_mac_msw_shift_b1.

◆ demo_panic_halt()

void demo_panic_halt ( void )

static

Halt forever in WFI.

Precondition: Called only after a fatal error.

Postcondition: CPU is parked.

Since: 0.1.0

Definition at line 201 of file main.c.

◆ demo_print()

void demo_print ( const char * s )

static

Convenience wrapper to write a NUL-terminated string to SCI8.

Parameters

[in] s NUL-terminated ASCII string. Must not be NULL.

Precondition: s != NULL.

Postcondition: Bytes are queued in the SCI8 TX FIFO (best-effort).

Since: 0.1.0

Definition at line 248 of file main.c.

References ra8_board_uart_console_write(), and strlen().

◆ demo_setup_or_halt()

void demo_setup_or_halt ( void )

static

Bring CGC + the J-Link OB VCOM console + on-board Ethernet up.

Precondition: Reset_Handler / SystemInit complete.

Postcondition: On success the BSP console is sending at 115200 8N1 and the on-board RGMII PHY pins + ETHA0 / RMAC0 are initialized.

Since: 0.1.0

Definition at line 217 of file main.c.

References demo_panic_halt(), k_demo_baud, k_ra8_clock_id_cpuclk0, k_ra8_ok, ra8_board_ethernet_init(), ra8_board_uart_console_init(), ra8_cgc_get_clock_hz(), ra8_cgc_init(), and ra8_time_init().

◆ demo_thread_entry()

void demo_thread_entry ( ULONG thread_input )

static

ThreadX worker entry: bring NetX up, then run the echo loop.

Parameters

[in] thread_input Unused.

Precondition: nx_system_initialize has run.

Postcondition: Echo loop runs forever.

Since: 0.1.0

Definition at line 551 of file main.c.

References demo_echo_loop(), demo_netx_bring_up(), and demo_print().

◆ main()

void main ( void )

Application entry.

The application entry point Reset_Handler hands control to.

Brings up clocks + UART + RMII pins, then enters ThreadX.

Precondition: Reset_Handler has copied .data and zeroed .bss.

Postcondition: On clean entry the kernel runs the worker thread once.

Since: 0.1.0

Definition at line 609 of file main.c.

References demo_panic_halt(), demo_print(), demo_setup_or_halt(), and ra8_isr_globals_enable().

◆ tx_application_define()

void tx_application_define ( void * first_unused_memory )

ThreadX system-define hook: build worker thread + NetX core.

Parameters

[in] first_unused_memory Pointer to free RAM provided by the ThreadX port; unused – we statically allocate.

Precondition: tx_kernel_enter() has been called.

Postcondition: One worker thread is created and NetX is initialized.

Since: 0.1.0

Definition at line 580 of file main.c.

References demo_thread_entry(), k_demo_app_thread_pri, s_demo_stack, s_demo_thread, s_thread_name, TX_AUTO_START, TX_NO_TIME_SLICE, and tx_thread_create.

Variable Documentation

◆ k_demo_ip

const uint8_t k_demo_ip[4]

static

Initial value:

= {k_demo_ipaddr_0,
      k_demo_ipaddr_1,
      k_demo_ipaddr_2,
      k_demo_ipaddr_3}

IPv4 address: 192.168.1.42 / 255.255.255.0.

Definition at line 170 of file main.c.

◆ k_demo_mac

const uint8_t k_demo_mac[6] = {0x02U, 0x00U, 0x00U, 0x00U, 0x00U, 0x01U}

static

Definition at line 167 of file main.c.

◆ k_demo_mask

const uint8_t k_demo_mask[4] = {k_demo_netmask_b, k_demo_netmask_b, k_demo_netmask_b, 0U}

static

Subnet mask: 255.255.255.0.

Definition at line 176 of file main.c.

◆ s_arp_cache

ULONG s_arp_cache[k_demo_arp_cache/sizeof(ULONG)]

static

Definition at line 186 of file main.c.

◆ s_demo_stack

UCHAR s_demo_stack[k_demo_thread_stack]

static

Definition at line 190 of file main.c.

◆ s_demo_thread

TX_THREAD s_demo_thread

static

Definition at line 189 of file main.c.

◆ s_echo_socket

NX_TCP_SOCKET s_echo_socket

static

Definition at line 183 of file main.c.

Referenced by demo_echo_loop(), and demo_netx_bring_up().

◆ s_ip

NX_IP s_ip

static

Definition at line 182 of file main.c.

◆ s_ip_stack

ULONG s_ip_stack[k_demo_ip_stack/sizeof(ULONG)]

static

Definition at line 185 of file main.c.

◆ s_packet_pool

NX_PACKET_POOL s_packet_pool

static

Definition at line 181 of file main.c.

◆ s_pool_memory

UCHAR s_pool_memory[k_demo_pool_bytes]

static

Definition at line 184 of file main.c.

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ demo_config_t

◆ demo_decimal_t

◆ demo_ip_octet_t

◆ demo_ip_shift_t

◆ demo_ipv4_t

◆ demo_mac_idx_t

◆ demo_mac_word_shift_t

Function Documentation

◆ demo_append_byte()

◆ demo_echo_loop()

◆ demo_log_echo()

◆ demo_netx_bring_up()

◆ demo_netx_create_ip()

◆ demo_pack_ip()

◆ demo_pack_mac()

◆ demo_panic_halt()

◆ demo_print()

◆ demo_setup_or_halt()

◆ demo_thread_entry()

◆ main()

◆ tx_application_define()

Variable Documentation

◆ k_demo_ip

◆ k_demo_mac

◆ k_demo_mask

◆ s_arp_cache

◆ s_demo_stack

◆ s_demo_thread

◆ s_echo_socket

◆ s_ip

◆ s_ip_stack

◆ s_packet_pool

◆ s_pool_memory