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/openrisc/cpu/interrupts.c

@@ -0,0 +1,108 @@
+/*
+ * (C) Copyright 2011, Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
+ * (C) Copyright 2011, Julius Baxter <julius@opencores.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/types.h>
+#include <asm/ptrace.h>
+#include <asm/system.h>
+#include <asm/openrisc_exc.h>
+
+struct irq_action {
+	interrupt_handler_t *handler;
+	void *arg;
+	int count;
+};
+
+static struct irq_action handlers[32];
+
+void interrupt_handler(void)
+{
+	int irq;
+
+	while ((irq = ffs(mfspr(SPR_PICSR)))) {
+		if (handlers[--irq].handler) {
+			handlers[irq].handler(handlers[irq].arg);
+			handlers[irq].count++;
+		} else {
+			/* disable the interrupt */
+			mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1 << irq));
+			printf("Unhandled interrupt: %d\n", irq);
+		}
+		/* clear the interrupt */
+		mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1 << irq));
+	}
+}
+
+int interrupt_init(void)
+{
+	/* install handler for external interrupt exception */
+	exception_install_handler(EXC_EXT_IRQ, interrupt_handler);
+	/* Enable interrupts in supervisor register */
+	mtspr(SPR_SR, mfspr(SPR_SR) | SPR_SR_IEE);
+
+	return 0;
+}
+
+void enable_interrupts(void)
+{
+	/* Set interrupt enable bit in supervisor register */
+	mtspr(SPR_SR, mfspr(SPR_SR) | SPR_SR_IEE);
+	/* Enable timer exception */
+	mtspr(SPR_SR, mfspr(SPR_SR) | SPR_SR_TEE);
+}
+
+int disable_interrupts(void)
+{
+	/* Clear interrupt enable bit in supervisor register */
+	mtspr(SPR_SR, mfspr(SPR_SR) & ~SPR_SR_IEE);
+	/* Disable timer exception */
+	mtspr(SPR_SR, mfspr(SPR_SR) & ~SPR_SR_TEE);
+
+	return 0;
+}
+
+void irq_install_handler(int irq, interrupt_handler_t *handler, void *arg)
+{
+	if (irq < 0 || irq > 31)
+		return;
+
+	handlers[irq].handler = handler;
+	handlers[irq].arg = arg;
+}
+
+void irq_free_handler(int irq)
+{
+	if (irq < 0 || irq > 31)
+		return;
+
+	handlers[irq].handler = 0;
+	handlers[irq].arg = 0;
+}
+
+#if defined(CONFIG_CMD_IRQ)
+int do_irqinfo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	int i;
+
+	printf("\nInterrupt-Information:\n\n");
+	printf("Nr  Routine   Arg       Count\n");
+	printf("-----------------------------\n");
+
+	for (i = 0; i < 32; i++) {
+		if (handlers[i].handler) {
+			printf("%02d  %08lx  %08lx  %d\n",
+				i,
+				(ulong)handlers[i].handler,
+				(ulong)handlers[i].arg,
+				handlers[i].count);
+		}
+	}
+	printf("\n");
+
+	return 0;
+}
+#endif