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/lib/tiny-printf.c

@@ -0,0 +1,187 @@
+/*
+ * Tiny printf version for SPL
+ *
+ * Copied from:
+ * http://www.sparetimelabs.com/printfrevisited/printfrevisited.php
+ *
+ * Copyright (C) 2004,2008  Kustaa Nyholm
+ *
+ * SPDX-License-Identifier:	LGPL-2.1+
+ */
+
+#include <common.h>
+#include <stdarg.h>
+#include <serial.h>
+
+/*
+ * This code in here may execute before the DRAM is initialised, so
+ * we should make sure that it doesn't touch BSS, which some boards
+ * put in DRAM.
+ */
+static char *bf __attribute__ ((section(".data")));
+static char zs __attribute__ ((section(".data")));
+
+/* Current position in sprintf() output string */
+static char *outstr __attribute__ ((section(".data")));
+
+static void out(char c)
+{
+	*bf++ = c;
+}
+
+static void out_dgt(char dgt)
+{
+	out(dgt + (dgt < 10 ? '0' : 'a' - 10));
+	zs = 1;
+}
+
+static void div_out(unsigned int *num, unsigned int div)
+{
+	unsigned char dgt = 0;
+
+	while (*num >= div) {
+		*num -= div;
+		dgt++;
+	}
+
+	if (zs || dgt > 0)
+		out_dgt(dgt);
+}
+
+int _vprintf(const char *fmt, va_list va, void (*putc)(const char ch))
+{
+	char ch;
+	char *p;
+	unsigned int num;
+	char buf[12];
+	unsigned int div;
+
+	while ((ch = *(fmt++))) {
+		if (ch != '%') {
+			putc(ch);
+		} else {
+			bool lz = false;
+			int width = 0;
+
+			ch = *(fmt++);
+			if (ch == '0') {
+				ch = *(fmt++);
+				lz = 1;
+			}
+
+			if (ch >= '0' && ch <= '9') {
+				width = 0;
+				while (ch >= '0' && ch <= '9') {
+					width = (width * 10) + ch - '0';
+					ch = *fmt++;
+				}
+			}
+			bf = buf;
+			p = bf;
+			zs = 0;
+
+			switch (ch) {
+			case '\0':
+				goto abort;
+			case 'u':
+			case 'd':
+				num = va_arg(va, unsigned int);
+				if (ch == 'd' && (int)num < 0) {
+					num = -(int)num;
+					out('-');
+				}
+				if (!num) {
+					out_dgt(0);
+				} else {
+					for (div = 1000000000; div; div /= 10)
+						div_out(&num, div);
+				}
+				break;
+			case 'x':
+				num = va_arg(va, unsigned int);
+				if (!num) {
+					out_dgt(0);
+				} else {
+					for (div = 0x10000000; div; div /= 0x10)
+						div_out(&num, div);
+				}
+				break;
+			case 'c':
+				out((char)(va_arg(va, int)));
+				break;
+			case 's':
+				p = va_arg(va, char*);
+				break;
+			case '%':
+				out('%');
+			default:
+				break;
+			}
+
+			*bf = 0;
+			bf = p;
+			while (*bf++ && width > 0)
+				width--;
+			while (width-- > 0)
+				putc(lz ? '0' : ' ');
+			if (p) {
+				while ((ch = *p++))
+					putc(ch);
+			}
+		}
+	}
+
+abort:
+	return 0;
+}
+
+int vprintf(const char *fmt, va_list va)
+{
+	return _vprintf(fmt, va, putc);
+}
+
+int printf(const char *fmt, ...)
+{
+	va_list va;
+	int ret;
+
+	va_start(va, fmt);
+	ret = _vprintf(fmt, va, putc);
+	va_end(va);
+
+	return ret;
+}
+
+static void putc_outstr(char ch)
+{
+	*outstr++ = ch;
+}
+
+int sprintf(char *buf, const char *fmt, ...)
+{
+	va_list va;
+	int ret;
+
+	va_start(va, fmt);
+	outstr = buf;
+	ret = _vprintf(fmt, va, putc_outstr);
+	va_end(va);
+	*outstr = '\0';
+
+	return ret;
+}
+
+/* Note that size is ignored */
+int snprintf(char *buf, size_t size, const char *fmt, ...)
+{
+	va_list va;
+	int ret;
+
+	va_start(va, fmt);
+	outstr = buf;
+	ret = _vprintf(fmt, va, putc_outstr);
+	va_end(va);
+	*outstr = '\0';
+
+	return ret;
+}