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/drivers/serial/serial_arc.c

@@ -0,0 +1,132 @@
+/*
+ * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <serial.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct arc_serial_regs {
+	unsigned int id0;
+	unsigned int id1;
+	unsigned int id2;
+	unsigned int id3;
+	unsigned int data;
+	unsigned int status;
+	unsigned int baudl;
+	unsigned int baudh;
+};
+
+
+struct arc_serial_platdata {
+	struct arc_serial_regs *reg;
+	unsigned int uartclk;
+};
+
+/* Bit definitions of STATUS register */
+#define UART_RXEMPTY		(1 << 5)
+#define UART_OVERFLOW_ERR	(1 << 1)
+#define UART_TXEMPTY		(1 << 7)
+
+static int arc_serial_setbrg(struct udevice *dev, int baudrate)
+{
+	struct arc_serial_platdata *plat = dev->platdata;
+	struct arc_serial_regs *const regs = plat->reg;
+	int arc_console_baud = gd->cpu_clk / (baudrate * 4) - 1;
+
+	writeb(arc_console_baud & 0xff, &regs->baudl);
+	writeb((arc_console_baud & 0xff00) >> 8, &regs->baudh);
+
+	return 0;
+}
+
+static int arc_serial_putc(struct udevice *dev, const char c)
+{
+	struct arc_serial_platdata *plat = dev->platdata;
+	struct arc_serial_regs *const regs = plat->reg;
+
+	while (!(readb(&regs->status) & UART_TXEMPTY))
+		;
+
+	writeb(c, &regs->data);
+
+	return 0;
+}
+
+static int arc_serial_tstc(struct arc_serial_regs *const regs)
+{
+	return !(readb(&regs->status) & UART_RXEMPTY);
+}
+
+static int arc_serial_pending(struct udevice *dev, bool input)
+{
+	struct arc_serial_platdata *plat = dev->platdata;
+	struct arc_serial_regs *const regs = plat->reg;
+	uint32_t status = readb(&regs->status);
+
+	if (input)
+		return status & UART_RXEMPTY ? 0 : 1;
+	else
+		return status & UART_TXEMPTY ? 0 : 1;
+}
+
+static int arc_serial_getc(struct udevice *dev)
+{
+	struct arc_serial_platdata *plat = dev->platdata;
+	struct arc_serial_regs *const regs = plat->reg;
+
+	while (!arc_serial_tstc(regs))
+		;
+
+	/* Check for overflow errors */
+	if (readb(&regs->status) & UART_OVERFLOW_ERR)
+		return 0;
+
+	return readb(&regs->data) & 0xFF;
+}
+
+static int arc_serial_probe(struct udevice *dev)
+{
+	return 0;
+}
+
+static const struct dm_serial_ops arc_serial_ops = {
+	.putc = arc_serial_putc,
+	.pending = arc_serial_pending,
+	.getc = arc_serial_getc,
+	.setbrg = arc_serial_setbrg,
+};
+
+static const struct udevice_id arc_serial_ids[] = {
+	{ .compatible = "snps,arc-uart" },
+	{ }
+};
+
+static int arc_serial_ofdata_to_platdata(struct udevice *dev)
+{
+	struct arc_serial_platdata *plat = dev_get_platdata(dev);
+	DECLARE_GLOBAL_DATA_PTR;
+
+	plat->reg = (struct arc_serial_regs *)dev_get_addr(dev);
+	plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+				       "clock-frequency", 0);
+
+	return 0;
+}
+
+U_BOOT_DRIVER(serial_arc) = {
+	.name	= "serial_arc",
+	.id	= UCLASS_SERIAL,
+	.of_match = arc_serial_ids,
+	.ofdata_to_platdata = arc_serial_ofdata_to_platdata,
+	.probe = arc_serial_probe,
+	.ops	= &arc_serial_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};