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/post/drivers/rtc.c

@@ -0,0 +1,193 @@
+/*
+ * (C) Copyright 2002
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+
+/*
+ * RTC test
+ *
+ * The Real Time Clock (RTC) operation is verified by this test.
+ * The following features are verified:
+ *   o) RTC Power Fault
+ *	This is verified by analyzing the rtc_get() return status.
+ *   o) Time uniformity
+ *      This is verified by reading RTC in polling within
+ *      a short period of time.
+ *   o) Passing month boundaries
+ *      This is checked by setting RTC to a second before
+ *      a month boundary and reading it after its passing the
+ *      boundary. The test is performed for both leap- and
+ *      nonleap-years.
+ */
+
+#include <post.h>
+#include <rtc.h>
+
+#if CONFIG_POST & CONFIG_SYS_POST_RTC
+
+static int rtc_post_skip (ulong * diff)
+{
+	struct rtc_time tm1;
+	struct rtc_time tm2;
+	ulong start1;
+	ulong start2;
+
+	rtc_get (&tm1);
+	start1 = get_timer (0);
+
+	while (1) {
+		rtc_get (&tm2);
+		start2 = get_timer (0);
+		if (tm1.tm_sec != tm2.tm_sec)
+			break;
+		if (start2 - start1 > 1500)
+			break;
+	}
+
+	if (tm1.tm_sec != tm2.tm_sec) {
+		*diff = start2 - start1;
+
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+static void rtc_post_restore (struct rtc_time *tm, unsigned int sec)
+{
+	time_t t = rtc_mktime(tm) + sec;
+	struct rtc_time ntm;
+
+	rtc_to_tm(t, &ntm);
+
+	rtc_set (&ntm);
+}
+
+int rtc_post_test (int flags)
+{
+	ulong diff;
+	unsigned int i;
+	struct rtc_time svtm;
+	static unsigned int daysnl[] =
+			{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+	static unsigned int daysl[] =
+			{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+	unsigned int ynl = 1999;
+	unsigned int yl = 2000;
+	unsigned int skipped = 0;
+	int reliable;
+
+	/* Time reliability */
+	reliable = rtc_get (&svtm);
+
+	/* Time uniformity */
+	if (rtc_post_skip (&diff) != 0) {
+		post_log ("Timeout while waiting for a new second !\n");
+
+		return -1;
+	}
+
+	for (i = 0; i < 5; i++) {
+		if (rtc_post_skip (&diff) != 0) {
+			post_log ("Timeout while waiting for a new second !\n");
+
+			return -1;
+		}
+
+		if (diff < 950 || diff > 1050) {
+			post_log ("Invalid second duration !\n");
+
+			return -1;
+		}
+	}
+
+	/* Passing month boundaries */
+
+	if (rtc_post_skip (&diff) != 0) {
+		post_log ("Timeout while waiting for a new second !\n");
+
+		return -1;
+	}
+	rtc_get (&svtm);
+
+	for (i = 0; i < 12; i++) {
+		time_t t;
+		struct rtc_time tm;
+
+		tm.tm_year = ynl;
+		tm.tm_mon = i + 1;
+		tm.tm_mday = daysnl[i];
+		tm.tm_hour = 23;
+		tm.tm_min = 59;
+		tm.tm_sec = 59;
+		t = rtc_mktime(&tm);
+		rtc_to_tm(t, &tm);
+		rtc_set (&tm);
+
+		skipped++;
+		if (rtc_post_skip (&diff) != 0) {
+			rtc_post_restore (&svtm, skipped);
+			post_log ("Timeout while waiting for a new second !\n");
+
+			return -1;
+		}
+
+		rtc_get (&tm);
+		if (tm.tm_mon == i + 1) {
+			rtc_post_restore (&svtm, skipped);
+			post_log ("Month %d boundary is not passed !\n", i + 1);
+
+			return -1;
+		}
+	}
+
+	for (i = 0; i < 12; i++) {
+		time_t t;
+		struct rtc_time tm;
+
+		tm.tm_year = yl;
+		tm.tm_mon = i + 1;
+		tm.tm_mday = daysl[i];
+		tm.tm_hour = 23;
+		tm.tm_min = 59;
+		tm.tm_sec = 59;
+		t = rtc_mktime(&tm);
+
+		rtc_to_tm(t, &tm);
+		rtc_set (&tm);
+
+		skipped++;
+		if (rtc_post_skip (&diff) != 0) {
+			rtc_post_restore (&svtm, skipped);
+			post_log ("Timeout while waiting for a new second !\n");
+
+			return -1;
+		}
+
+		rtc_get (&tm);
+		if (tm.tm_mon == i + 1) {
+			rtc_post_restore (&svtm, skipped);
+			post_log ("Month %d boundary is not passed !\n", i + 1);
+
+			return -1;
+		}
+	}
+	rtc_post_restore (&svtm, skipped);
+
+	/* If come here, then RTC operates correcty, check the correctness
+	 * of the time it reports.
+	 */
+	if (reliable < 0) {
+		post_log ("RTC Time is not reliable! Power fault? \n");
+
+		return -1;
+	}
+
+	return 0;
+}
+
+#endif /* CONFIG_POST & CONFIG_SYS_POST_RTC */