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/common/s_record.c

@@ -0,0 +1,179 @@
+/*
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <s_record.h>
+
+static int hex1_bin (char  c);
+static int hex2_bin (char *s);
+
+int srec_decode (char *input, int *count, ulong *addr, char *data)
+{
+	int	i;
+	int	v;				/* conversion buffer	*/
+	int	srec_type;			/* S-Record type	*/
+	unsigned char chksum;			/* buffer for checksum	*/
+
+	chksum = 0;
+
+	/* skip anything before 'S', and the 'S' itself.
+	 * Return error if not found
+	 */
+
+	for (; *input; ++input) {
+		if (*input == 'S') {		/* skip 'S' */
+			++input;
+			break;
+		}
+	}
+	if (*input == '\0') {			/* no more data?	*/
+		return (SREC_EMPTY);
+	}
+
+	v = *input++;				/* record type		*/
+
+	if ((*count = hex2_bin(input)) < 0) {
+		return (SREC_E_NOSREC);
+	}
+
+	chksum += *count;
+	input  += 2;
+
+	switch (v) {				/* record type		*/
+
+	case '0':				/* start record		*/
+		srec_type = SREC_START;		/* 2 byte addr field	*/
+		*count   -= 3;			/* - checksum and addr	*/
+		break;
+	case '1':
+		srec_type = SREC_DATA2;		/* 2 byte addr field	*/
+		*count   -= 3;			/* - checksum and addr	*/
+		break;
+	case '2':
+		srec_type = SREC_DATA3;		/* 3 byte addr field	*/
+		*count   -= 4;			/* - checksum and addr	*/
+		break;
+	case '3':				/* data record with a	*/
+		srec_type = SREC_DATA4;		/* 4 byte addr field	*/
+		*count   -= 5;			/* - checksum and addr	*/
+		break;
+/***	case '4'  ***/
+	case '5':			/* count record, addr field contains */
+		srec_type = SREC_COUNT;	/* a 2 byte record counter	*/
+		*count    = 0;			/* no data		*/
+		break;
+/***	case '6' -- not used  ***/
+	case '7':				/* end record with a	*/
+		srec_type = SREC_END4;		/* 4 byte addr field	*/
+		*count   -= 5;			/* - checksum and addr	*/
+		break;
+	case '8':				/* end record with a	*/
+		srec_type = SREC_END3;		/* 3 byte addr field	*/
+		*count   -= 4;			/* - checksum and addr	*/
+		break;
+	case '9':				/* end record with a	*/
+		srec_type = SREC_END2;		/* 2 byte addr field	*/
+		*count   -= 3;			/* - checksum and addr	*/
+		break;
+	default:
+		return (SREC_E_BADTYPE);
+	}
+
+	/* read address field */
+	*addr = 0;
+
+	switch (v) {
+	case '3':				/* 4 byte addr field	*/
+	case '7':
+		if ((v = hex2_bin(input)) < 0) {
+			return (SREC_E_NOSREC);
+		}
+		*addr  += v;
+		chksum += v;
+		input  += 2;
+		/* FALL THRU */
+	case '2':				/* 3 byte addr field	*/
+	case '8':
+		if ((v = hex2_bin(input)) < 0) {
+			return (SREC_E_NOSREC);
+		}
+		*addr <<= 8;
+		*addr  += v;
+		chksum += v;
+		input  += 2;
+		/* FALL THRU */
+	case '0':				/* 2 byte addr field	*/
+	case '1':
+	case '5':
+	case '9':
+		if ((v = hex2_bin(input)) < 0) {
+			return (SREC_E_NOSREC);
+		}
+		*addr <<= 8;
+		*addr  += v;
+		chksum += v;
+		input  += 2;
+
+		if ((v = hex2_bin(input)) < 0) {
+			return (SREC_E_NOSREC);
+		}
+		*addr <<= 8;
+		*addr  += v;
+		chksum += v;
+		input  += 2;
+
+		break;
+	default:
+		return (SREC_E_BADTYPE);
+	}
+
+	/* convert data and calculate checksum */
+	for (i=0; i < *count; ++i) {
+		if ((v = hex2_bin(input)) < 0) {
+			return (SREC_E_NOSREC);
+		}
+		data[i] = v;
+		chksum += v;
+		input  += 2;
+	}
+
+	/* read anc check checksum */
+	if ((v = hex2_bin(input)) < 0) {
+		return (SREC_E_NOSREC);
+	}
+
+	if ((unsigned char)v != (unsigned char)~chksum) {
+		return (SREC_E_BADCHKS);
+	}
+
+	return (srec_type);
+}
+
+static int hex1_bin (char c)
+{
+	if (c >= '0' && c <= '9')
+		return (c - '0');
+	if (c >= 'a' && c <= 'f')
+		return (c + 10 - 'a');
+	if (c >= 'A' && c <= 'F')
+		return (c + 10 - 'A');
+	return (-1);
+}
+
+static int hex2_bin (char *s)
+{
+	int i, j;
+
+	if ((i = hex1_bin(*s++)) < 0) {
+		return (-1);
+	}
+	if ((j = hex1_bin(*s)) < 0) {
+		return (-1);
+	}
+
+	return ((i<<4) + j);
+}