#define TESTMUSTER_55  0x55555555
#define TESTMUSTER_AA  0xAAAAAAAA
#define ERROR_NO_ERROR 0
#define TEST_MEM_FAIL  1


bool check_registers()
{
	bool ergebnis = ERROR_NO_ERROR;

	__DSB();
	__ISB();
	
	asm volatile(
		"MOV R1, %[M55]"       "\n\t"
		"MOV R2, %[MAA]"       "\n\t"
		
		"MOV R0, #0x55"        "\n\t"
		"LSL R0, R0, #8"       "\n\t"
		"ADD R0, R0, #0x55"    "\n\t"
		"LSL R0, R0, #8"       "\n\t"
		"ADD R0, R0, #0x55"    "\n\t"
		"LSL R0, R0, #8"       "\n\t"
		"ADD R0, R0, #0x55"    "\n\t"
		
		"CMP R0, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"

		"MOV R0, #0xAA"        "\n\t"
		"LSL R0, R0, #8"       "\n\t"
		"ADD R0, R0, #0xAA"    "\n\t"
		"LSL R0, R0, #8"       "\n\t"
		"ADD R0, R0, #0xAA"    "\n\t"
		"LSL R0, R0, #8"       "\n\t"
		"ADD R0, R0, #0xAA"    "\n\t"
		
		"CMP R0, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		
		"MOV R1, %[MAA]"       "\n\t"
		"CMP R1, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		
		"MOV R1, %[M55]"       "\n\t"
		"MOV R2, %[M55]"       "\n\t"
		"CMP R1, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		
		"MOV R2, %[MAA]"       "\n\t"
		"CMP R0, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"

		"MOV R0, R3"           "\n\t"
		"MOV R3, R1"           "\n\t"
		"CMP R3, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R3, R2"           "\n\t"
		"CMP R3, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R3, R0"           "\n\t"

		"MOV R0, R4"           "\n\t"
		"MOV R4, R1"           "\n\t"
		"CMP R4, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R4, R2"           "\n\t"
		"CMP R4, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R4, R0"           "\n\t"

		"MOV R0, R5"           "\n\t"
		"MOV R5, R1"           "\n\t"
		"CMP R5, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R5, R2"           "\n\t"
		"CMP R5, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R5, R0"           "\n\t"

		"MOV R0, R6"           "\n\t"
		"MOV R6, R1"           "\n\t"
		"CMP R6, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R6, R2"           "\n\t"
		"CMP R6, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R6, R0"           "\n\t"

		"MOV R0, R7"           "\n\t"
		"MOV R7, R1"           "\n\t"
		"CMP R7, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R7, R2"           "\n\t"
		"CMP R7, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R7, R0"           "\n\t"

		"MOV R0, R8"           "\n\t"
		"MOV R8, R1"           "\n\t"
		"CMP R8, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R8, R2"           "\n\t"
		"CMP R8, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R8, R0"           "\n\t"

		"MOV R0, R9"           "\n\t"
		"MOV R9, R1"           "\n\t"
		"CMP R9, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R9, R2"           "\n\t"
		"CMP R9, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R9, R0"           "\n\t"

		"MOV R0, R10"           "\n\t"
		"MOV R10, R1"           "\n\t"
		"CMP R10, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R10, R2"           "\n\t"
		"CMP R10, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R10, R0"           "\n\t"

		"MOV R0, R11"           "\n\t"
		"MOV R11, R1"           "\n\t"
		"CMP R11, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R11, R2"           "\n\t"
		"CMP R11, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R11, R0"           "\n\t"

		"MOV R0, R12"           "\n\t"
		"MOV R12, R1"           "\n\t"
		"CMP R12, R1"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R12, R2"           "\n\t"
		"CMP R12, R2"           "\n\t"
		"BNE FEHLER_LR_%="     "\n\t"
		"MOV R12, R0"           "\n\t"

		"TEST_LR_OK_%=:"                    "\n\t"	// RAM ok:
			"MOV   %[ERG], %[TST_OK]"       "\n\t"	// return TST_OK
			"B     ENDE_%="                 "\n\t"	// -> Ende
		"FEHLER_LR_%=:"                     "\n\t"	// Fehler:
			"MOV   %[ERG], %[TST_FAIL]"     "\n\t"	// return TST_FAIL
		"ENDE_%=:"                          "\n\t"	// Ende:

		: [ERG]      "=r" (ergebnis)         	// return Wert
		: [M55]      "r" (TESTMUSTER_55),    	// Testmuster A
		  [MAA]      "r" (TESTMUSTER_AA),    	// Testmuster B
		  [TST_OK]   "M" (ERROR_NO_ERROR),          	// Rückgabewert bei Test ok
		  [TST_FAIL] "M" (TEST_MEM_FAIL)     	// Rückgabewert bei Fehler
		: "r0", "r1", "r2");                 	// Benutzte Register

// Stack-Pointer
	if (ergebnis == ERROR_NO_ERROR)
	{
		asm volatile(
			"MOV R0, R13"           "\n\t"
			"MOV R13, %[M55]"       "\n\t"
			"CMP R13, %[M55]"       "\n\t"
			"BNE FEHLER_LR_%="      "\n\t"
			"MOV R13, %[MAA]"       "\n\t"
			"CMP R13, %[MAA]"       "\n\t"
			"BNE FEHLER_LR_%="      "\n\t"
			"MOV R13, R0"           "\n\t"
			"TEST_LR_OK_%=:"                "\n\t"	// RAM ok:
				"MOV   %[ERG], %[TST_OK]"   "\n\t"	// return TST_OK
				"B     ENDE_%="             "\n\t"	// -> Ende
			"FEHLER_LR_%=:"                 "\n\t"	// Fehler:
				"MOV   %[ERG], %[TST_FAIL]" "\n\t"	// return TST_FAIL
			"ENDE_%=:"                      "\n\t"	// Ende:

			: [ERG]      "=r" (ergebnis)         	// return Wert
			: [M55]      "r" (TESTMUSTER_SP_55), 	// Testmuster A
			  [MAA]      "r" (TESTMUSTER_SP_55), 	// Testmuster B
			  [TST_OK]   "M" (ERROR_NO_ERROR),          	// Rückgabewert bei Test ok
			  [TST_FAIL] "M" (TEST_MEM_FAIL)     	// Rückgabewert bei Fehler
			: "r0");                             	// Benutzte Register
	}

// Link Register
	if (ergebnis == ERROR_NO_ERROR)
	{
		asm volatile(
			"MOV R0, R14"           "\n\t"
			"MOV R14, %[M55]"       "\n\t"
			"CMP R14, %[M55]"       "\n\t"
			"BNE FEHLER_LR_%="      "\n\t"
			"MOV R14, %[MAA]"       "\n\t"
			"CMP R14, %[MAA]"       "\n\t"
			"BNE FEHLER_LR_%="      "\n\t"
			"MOV R14, R0"           "\n\t"
			"TEST_LR_OK_%=:"                "\n\t"	// RAM ok:
				"MOV   %[ERG], %[TST_OK]"   "\n\t"	// return TST_OK
				"B     ENDE_%="             "\n\t"	// -> Ende
			"FEHLER_LR_%=:"                 "\n\t"	// Fehler:
				"MOV   %[ERG], %[TST_FAIL]" "\n\t"	// return TST_FAIL
			"ENDE_%=:"                      "\n\t"	// Ende:

			: [ERG]      "=r" (ergebnis)         	// return Wert
			: [M55]      "r" (TESTMUSTER_55),    	// Testmuster A
			  [MAA]      "r" (TESTMUSTER_AA),    	// Testmuster B
			  [TST_OK]   "M" (ERROR_NO_ERROR),          	// Rückgabewert bei Test ok
			  [TST_FAIL] "M" (TEST_MEM_FAIL)     	// Rückgabewert bei Fehler
			: "r0");                             	// Benutzte Register
	}

	return ergebnis;
}