avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/net/ping.c

@@ -0,0 +1,115 @@
+/*
+ *	Copied from Linux Monitor (LiMon) - Networking.
+ *
+ *	Copyright 1994 - 2000 Neil Russell.
+ *	(See License)
+ *	Copyright 2000 Roland Borde
+ *	Copyright 2000 Paolo Scaffardi
+ *	Copyright 2000-2002 Wolfgang Denk, wd@denx.de
+ *	SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include "ping.h"
+#include "arp.h"
+
+static ushort ping_seq_number;
+
+/* The ip address to ping */
+struct in_addr net_ping_ip;
+
+static void set_icmp_header(uchar *pkt, struct in_addr dest)
+{
+	/*
+	 *	Construct an IP and ICMP header.
+	 */
+	struct ip_hdr *ip = (struct ip_hdr *)pkt;
+	struct icmp_hdr *icmp = (struct icmp_hdr *)(pkt + IP_HDR_SIZE);
+
+	net_set_ip_header(pkt, dest, net_ip);
+
+	ip->ip_len   = htons(IP_ICMP_HDR_SIZE);
+	ip->ip_p     = IPPROTO_ICMP;
+	ip->ip_sum   = compute_ip_checksum(ip, IP_HDR_SIZE);
+
+	icmp->type = ICMP_ECHO_REQUEST;
+	icmp->code = 0;
+	icmp->checksum = 0;
+	icmp->un.echo.id = 0;
+	icmp->un.echo.sequence = htons(ping_seq_number++);
+	icmp->checksum = compute_ip_checksum(icmp, ICMP_HDR_SIZE);
+}
+
+static int ping_send(void)
+{
+	uchar *pkt;
+	int eth_hdr_size;
+
+	/* XXX always send arp request */
+
+	debug_cond(DEBUG_DEV_PKT, "sending ARP for %pI4\n", &net_ping_ip);
+
+	net_arp_wait_packet_ip = net_ping_ip;
+
+	eth_hdr_size = net_set_ether(net_tx_packet, net_null_ethaddr, PROT_IP);
+	pkt = (uchar *)net_tx_packet + eth_hdr_size;
+
+	set_icmp_header(pkt, net_ping_ip);
+
+	/* size of the waiting packet */
+	arp_wait_tx_packet_size = eth_hdr_size + IP_ICMP_HDR_SIZE;
+
+	/* and do the ARP request */
+	arp_wait_try = 1;
+	arp_wait_timer_start = get_timer(0);
+	arp_request();
+	return 1;	/* waiting */
+}
+
+static void ping_timeout_handler(void)
+{
+	eth_halt();
+	net_set_state(NETLOOP_FAIL);	/* we did not get the reply */
+}
+
+void ping_start(void)
+{
+	printf("Using %s device\n", eth_get_name());
+	net_set_timeout_handler(10000UL, ping_timeout_handler);
+
+	ping_send();
+}
+
+void ping_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
+{
+	struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
+	struct in_addr src_ip;
+	int eth_hdr_size;
+
+	switch (icmph->type) {
+	case ICMP_ECHO_REPLY:
+		src_ip = net_read_ip((void *)&ip->ip_src);
+		if (src_ip.s_addr == net_ping_ip.s_addr)
+			net_set_state(NETLOOP_SUCCESS);
+		return;
+	case ICMP_ECHO_REQUEST:
+		eth_hdr_size = net_update_ether(et, et->et_src, PROT_IP);
+
+		debug_cond(DEBUG_DEV_PKT,
+			   "Got ICMP ECHO REQUEST, return %d bytes\n",
+			   eth_hdr_size + len);
+
+		ip->ip_sum = 0;
+		ip->ip_off = 0;
+		net_copy_ip((void *)&ip->ip_dst, &ip->ip_src);
+		net_copy_ip((void *)&ip->ip_src, &net_ip);
+		ip->ip_sum = compute_ip_checksum(ip, IP_HDR_SIZE);
+
+		icmph->type = ICMP_ECHO_REPLY;
+		icmph->checksum = 0;
+		icmph->checksum = compute_ip_checksum(icmph, len - IP_HDR_SIZE);
+		net_send_packet((uchar *)et, eth_hdr_size + len);
+		return;
+/*	default:
+		return;*/
+	}
+}