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/board/qemu-mips/lowlevel_init.S

@@ -0,0 +1,40 @@
+/* Memory sub-system initialization code */
+
+#include <config.h>
+#include <asm/regdef.h>
+#include <asm/mipsregs.h>
+
+	.text
+	.set noreorder
+	.set mips32
+
+	.globl	lowlevel_init
+lowlevel_init:
+
+	/*
+	 * Step 2) Establish Status Register
+	 * (set BEV, clear ERL, clear EXL, clear IE)
+	 */
+	li	t1, 0x00400000
+	mtc0	t1, CP0_STATUS
+
+	/*
+	 * Step 3) Establish CP0 Config0
+	 * (set K0=3)
+	 */
+	li	t1, 0x00000003
+	mtc0	t1, CP0_CONFIG
+
+	/*
+	 * Step 7) Establish Cause
+	 * (set IV bit)
+	 */
+	li	t1, 0x00800000
+	mtc0	t1, CP0_CAUSE
+
+	/* Establish Wired (and Random) */
+	mtc0	zero, CP0_WIRED
+	nop
+
+	jr	ra
+	nop