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/arch/avr32/cpu/interrupts.c

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+#include <common.h>
+#include <div64.h>
+
+#include <asm/errno.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/sysreg.h>
+
+#include <asm/arch/hardware.h>
+
+#define HANDLER_MASK	0x00ffffff
+#define INTLEV_SHIFT	30
+#define INTLEV_MASK	0x00000003
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Incremented whenever COUNT reaches 0xffffffff by timer_interrupt_handler */
+volatile unsigned long timer_overflow;
+
+/*
+ * Instead of dividing by get_tbclk(), multiply by this constant and
+ * right-shift the result by 32 bits.
+ */
+static unsigned long tb_factor;
+
+unsigned long get_tbclk(void)
+{
+	return gd->arch.cpu_hz;
+}
+
+unsigned long long get_ticks(void)
+{
+	unsigned long lo, hi_now, hi_prev;
+
+	do {
+		hi_prev = timer_overflow;
+		lo = sysreg_read(COUNT);
+		hi_now = timer_overflow;
+	} while (hi_prev != hi_now);
+
+	return ((unsigned long long)hi_now << 32) | lo;
+}
+
+unsigned long get_timer(unsigned long base)
+{
+	u64 now = get_ticks();
+
+	now *= tb_factor;
+	return (unsigned long)(now >> 32) - base;
+}
+
+/*
+ * For short delays only. It will overflow after a few seconds.
+ */
+void __udelay(unsigned long usec)
+{
+	unsigned long cycles;
+	unsigned long base;
+	unsigned long now;
+
+	base = sysreg_read(COUNT);
+	cycles = ((usec * (get_tbclk() / 10000)) + 50) / 100;
+
+	do {
+		now = sysreg_read(COUNT);
+	} while ((now - base) < cycles);
+}
+
+static int set_interrupt_handler(unsigned int nr, void (*handler)(void),
+				 unsigned int priority)
+{
+	extern void _evba(void);
+	unsigned long intpr;
+	unsigned long handler_addr = (unsigned long)handler;
+
+	handler_addr -= (unsigned long)&_evba;
+
+	if ((handler_addr & HANDLER_MASK) != handler_addr
+	    || (priority & INTLEV_MASK) != priority)
+		return -EINVAL;
+
+	intpr = (handler_addr & HANDLER_MASK);
+	intpr |= (priority & INTLEV_MASK) << INTLEV_SHIFT;
+	writel(intpr, (void *)ATMEL_BASE_INTC + 4 * nr);
+
+	return 0;
+}
+
+int timer_init(void)
+{
+	extern void timer_interrupt_handler(void);
+	u64 tmp;
+
+	sysreg_write(COUNT, 0);
+
+	tmp = (u64)CONFIG_SYS_HZ << 32;
+	tmp += gd->arch.cpu_hz / 2;
+	do_div(tmp, gd->arch.cpu_hz);
+	tb_factor = (u32)tmp;
+
+	if (set_interrupt_handler(0, &timer_interrupt_handler, 3))
+		return -EINVAL;
+
+	/* For all practical purposes, this gives us an overflow interrupt */
+	sysreg_write(COMPARE, 0xffffffff);
+	return 0;
+}