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/examples/standalone/stubs.c

@@ -0,0 +1,282 @@
+#include <common.h>
+#include <exports.h>
+#include <linux/compiler.h>
+
+#define FO(x) offsetof(struct jt_funcs, x)
+
+#if defined(CONFIG_X86)
+/*
+ * x86 does not have a dedicated register to store the pointer to
+ * the global_data. Thus the jump table address is stored in a
+ * global variable, but such approach does not allow for execution
+ * from flash memory. The global_data address is passed as argv[-1]
+ * to the application program.
+ */
+static struct jt_funcs *jt;
+gd_t *global_data;
+
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	movl	%0, %%eax\n"		\
+"	movl	jt, %%ecx\n"		\
+"	jmp	*(%%ecx, %%eax)\n"	\
+	: : "i"(FO(x)) : "eax", "ecx");
+#elif defined(CONFIG_PPC)
+/*
+ * r2 holds the pointer to the global_data, r11 is a call-clobbered
+ * register
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	lwz	%%r11, %0(%%r2)\n"	\
+"	lwz	%%r11, %1(%%r11)\n"	\
+"	mtctr	%%r11\n"		\
+"	bctr\n"				\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r11");
+#elif defined(CONFIG_ARM)
+#ifdef CONFIG_ARM64
+/*
+ * x18 holds the pointer to the global_data, x9 is a call-clobbered
+ * register
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	ldr	x9, [x18, %0]\n"		\
+"	ldr	x9, [x9, %1]\n"		\
+"	br	x9\n"		\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "x9");
+#else
+/*
+ * r9 holds the pointer to the global_data, ip is a call-clobbered
+ * register
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	ldr	ip, [r9, %0]\n"		\
+"	ldr	pc, [ip, %1]\n"		\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "ip");
+#endif
+#elif defined(CONFIG_MIPS)
+#ifdef CONFIG_CPU_MIPS64
+/*
+ * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call-
+ * clobbered register that is also used to set gp ($26). Note that the
+ * jr instruction also executes the instruction immediately following
+ * it; however, GCC/mips generates an additional `nop' after each asm
+ * statement
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	ld	$25, %0($26)\n"		\
+"	ld	$25, %1($25)\n"		\
+"	jr	$25\n"			\
+        : : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9");
+#else
+/*
+ * k0 ($26) holds the pointer to the global_data; t9 ($25) is a call-
+ * clobbered register that is also used to set gp ($26). Note that the
+ * jr instruction also executes the instruction immediately following
+ * it; however, GCC/mips generates an additional `nop' after each asm
+ * statement
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	lw	$25, %0($26)\n"		\
+"	lw	$25, %1($25)\n"		\
+"	jr	$25\n"			\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t9");
+#endif
+#elif defined(CONFIG_NIOS2)
+/*
+ * gp holds the pointer to the global_data, r8 is call-clobbered
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	movhi	r8, %%hi(%0)\n"		\
+"	ori	r8, r0, %%lo(%0)\n"	\
+"	add	r8, r8, gp\n"		\
+"	ldw	r8, 0(r8)\n"		\
+"	ldw	r8, %1(r8)\n"		\
+"	jmp	r8\n"			\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "gp");
+#elif defined(CONFIG_M68K)
+/*
+ * d7 holds the pointer to the global_data, a0 is a call-clobbered
+ * register
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	move.l	%%d7, %%a0\n"		\
+"	adda.l	%0, %%a0\n"		\
+"	move.l	(%%a0), %%a0\n"		\
+"	adda.l	%1, %%a0\n"		\
+"	move.l	(%%a0), %%a0\n"		\
+"	jmp	(%%a0)\n"			\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "a0");
+#elif defined(CONFIG_MICROBLAZE)
+/*
+ * r31 holds the pointer to the global_data. r5 is a call-clobbered.
+ */
+#define EXPORT_FUNC(f, a, x, ...)				\
+	asm volatile (				\
+"	.globl " #x "\n"			\
+#x ":\n"					\
+"	lwi	r5, r31, %0\n"			\
+"	lwi	r5, r5, %1\n"			\
+"	bra	r5\n"				\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r5");
+#elif defined(CONFIG_BLACKFIN)
+/*
+ * P3 holds the pointer to the global_data, P0 is a call-clobbered
+ * register
+ */
+#define EXPORT_FUNC(f, a, x, ...)			\
+	asm volatile (			\
+"	.globl _" #x "\n_"		\
+#x ":\n"				\
+"	P0 = [P3 + %0]\n"		\
+"	P0 = [P0 + %1]\n"		\
+"	JUMP (P0)\n"			\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "P0");
+#elif defined(CONFIG_AVR32)
+/*
+ * r6 holds the pointer to the global_data. r8 is call clobbered.
+ */
+#define EXPORT_FUNC(f, a, x, ...)					\
+	asm volatile(					\
+		"	.globl\t" #x "\n"		\
+		#x ":\n"				\
+		"	ld.w	r8, r6[%0]\n"		\
+		"	ld.w	pc, r8[%1]\n"		\
+		:					\
+		: "i"(offsetof(gd_t, jt)), "i"(FO(x))	\
+		: "r8");
+#elif defined(CONFIG_SH)
+/*
+ * r13 holds the pointer to the global_data. r1 is a call clobbered.
+ */
+#define EXPORT_FUNC(f, a, x, ...)					\
+	asm volatile (					\
+		"	.align	2\n"			\
+		"	.globl " #x "\n"		\
+		#x ":\n"				\
+		"	mov	r13, r1\n"		\
+		"	add	%0, r1\n"		\
+		"	mov.l @r1, r2\n"	\
+		"	add	%1, r2\n"		\
+		"	mov.l @r2, r1\n"	\
+		"	jmp	@r1\n"			\
+		"	nop\n"				\
+		"	nop\n"				\
+		: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r1", "r2");
+#elif defined(CONFIG_SPARC)
+/*
+ * g7 holds the pointer to the global_data. g1 is call clobbered.
+ */
+#define EXPORT_FUNC(f, a, x, ...)					\
+	asm volatile(					\
+"	.globl\t" #x "\n"				\
+#x ":\n"						\
+"	set %0, %%g1\n"					\
+"	or %%g1, %%g7, %%g1\n"				\
+"	ld [%%g1], %%g1\n"				\
+"	ld [%%g1 + %1], %%g1\n"				\
+"	jmp %%g1\n"					\
+"	nop\n"						\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "g1");
+#elif defined(CONFIG_NDS32)
+/*
+ * r16 holds the pointer to the global_data. gp is call clobbered.
+ * not support reduced register (16 GPR).
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	lwi	$r16, [$gp + (%0)]\n"	\
+"	lwi	$r16, [$r16 + (%1)]\n"	\
+"	jr	$r16\n"			\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "$r16");
+#elif defined(CONFIG_OPENRISC)
+/*
+ * r10 holds the pointer to the global_data, r13 is a call-clobbered
+ * register
+ */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	l.lwz	r13, %0(r10)\n"	\
+"	l.lwz	r13, %1(r13)\n"	\
+"	l.jr	r13\n"		\
+"	l.nop\n"				\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r13");
+#elif defined(CONFIG_ARC)
+/*
+ * r25 holds the pointer to the global_data. r10 is call clobbered.
+  */
+#define EXPORT_FUNC(f, a, x, ...) \
+	asm volatile( \
+"	.align 4\n" \
+"	.globl " #x "\n" \
+#x ":\n" \
+"	ld	r10, [r25, %0]\n" \
+"	ld	r10, [r10, %1]\n" \
+"	j	[r10]\n" \
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "r10");
+#else
+/*"	addi	$sp, $sp, -24\n"	\
+"	br	$r16\n"			\*/
+
+#error stubs definition missing for this architecture
+#endif
+
+/* This function is necessary to prevent the compiler from
+ * generating prologue/epilogue, preparing stack frame etc.
+ * The stub functions are special, they do not use the stack
+ * frame passed to them, but pass it intact to the actual
+ * implementation. On the other hand, asm() statements with
+ * arguments can be used only inside the functions (gcc limitation)
+ */
+#if GCC_VERSION < 30400
+static
+#endif /* GCC_VERSION */
+void __attribute__((unused)) dummy(void)
+{
+#include <_exports.h>
+}
+
+#include <asm/sections.h>
+
+void app_startup(char * const *argv)
+{
+	char *cp = __bss_start;
+
+	/* Zero out BSS */
+	while (cp < _end)
+		*cp++ = 0;
+
+#if defined(CONFIG_X86)
+	/* x86 does not have a dedicated register for passing global_data */
+	global_data = (gd_t *)argv[-1];
+	jt = global_data->jt;
+#endif
+}
+
+#undef EXPORT_FUNC