--- codec_interface.c.orig	Mon Jan  9 15:14:20 2023
+++ codec_interface.c	Mon Jan  9 15:14:20 2023
@@ -36,22 +36,17 @@ void codecDecode(uint8_t *indata_ptr, int numbBlocks)
 {
 	uint16_t bitbuffer_decode[49];
 
-
-	register int r0 asm ("r0") __attribute__((unused));
-	register int r1 asm ("r1") __attribute__((unused));
-	register int r2 asm ("r2") __attribute__((unused));
-
     for (int idx = 0; idx < numbBlocks; idx++)
     {
 		initFrame(indata_ptr, bitbuffer_decode);
 		indata_ptr += 9;
 
 		soundSetupBuffer();// this just sets currentWaveBuffer but the compiler seems to optimise out the code if I try to do it in this file
-		r2 = (int)bitbuffer_decode;
-		r0 = (int)currentWaveBuffer;
-		r1 = (int)ambebuffer_decode;
 
 		asm volatile (
+			"MOV R2, %0\n"
+			"MOV R0, %1\n"
+			"MOV R1, %2\n"
 			"PUSH {R4-R11}\n"
 			"SUB SP, SP, #0x10\n"
 			"STR R1, [SP, #0x08]\n"
@@ -64,16 +59,21 @@ void codecDecode(uint8_t *indata_ptr, int numbBlocks)
 			"BL " QU(AMBE_DECODE)
 			"ADD SP, SP, #0x10\n"
 			"POP {R4-R11}"
+			:
+			: "r"(bitbuffer_decode),
+			  "r"(currentWaveBuffer),
+			  "r"(ambebuffer_decode)
+			: "memory"
 		);
 
 		soundStoreBuffer();
 
 		soundSetupBuffer();// this just sets currentWaveBuffer but the compiler seems to optimise out the code if I try to do it in this file
-		r2 = (int)bitbuffer_decode;
-		r0 = (int)currentWaveBuffer;
-		r1 = (int)ambebuffer_decode;
 
 		asm volatile (
+			"MOV R2, %0\n"
+			"MOV R0, %1\n"
+			"MOV R1, %2\n"
 			"PUSH {R4-R11}\n"
 			"SUB SP, SP, #0x10\n"
 			"STR R1, [SP, #0x08]\n"
@@ -86,6 +86,11 @@ void codecDecode(uint8_t *indata_ptr, int numbBlocks)
 			"BL " QU(AMBE_DECODE)
 			"ADD SP, SP, #0x10\n"
 			"POP {R4-R11}"
+			:
+			: "r"(bitbuffer_decode),
+			  "r"(currentWaveBuffer),
+			  "r"(ambebuffer_decode)
+			: "memory"
 		);
 
 		soundStoreBuffer();
@@ -94,21 +99,16 @@ void codecDecode(uint8_t *indata_ptr, int numbBlocks)
 
 void codecEncodeBlock(uint8_t *outdata_ptr)
 {
-	register int r0 asm ("r0") __attribute__((unused));
-	register int r1 asm ("r1") __attribute__((unused));
-	register int r2 asm ("r2") __attribute__((unused));
-
 	memset((uint8_t *)outdata_ptr, 0, 9);// fills with zeros
 	memset(bitbuffer_encode, 0, sizeof(bitbuffer_encode));// faster to call memset as it will be compiled as optimised code
 
 
 	soundRetrieveBuffer();// gets currentWaveBuffer pointer used as input r2 to the encoder
 
-	r0 = (int)bitbuffer_encode;
-	r2 = (int)currentWaveBuffer;//tmp_wavbuffer;
-	r1 = (int)ambebuffer_encode;// seems to be a hard coded (defined) memory address of 0x1FFF6B60. I'm not sure why it has to be hard coded, since its passed as a paramater (register)
-
 	asm volatile (
+		"MOV R0, %0\n"
+		"MOV R2, %1\n"
+		"MOV R1, %2\n"
 		"PUSH {R4-R11}\n"
 		"SUB SP, SP, #0x14\n"
 		"STR R1, [SP, #0x0C]\n"
@@ -123,15 +123,22 @@ void codecEncodeBlock(uint8_t *outdata_ptr)
 		"BL " QU(AMBE_ENCODE)
 		"ADD SP, SP, #0x14\n"
 		"POP {R4-R11}"
+		:
+		: "r"(bitbuffer_encode),
+		  "r"(currentWaveBuffer), //tmp_wavbuffer
+		  /* seems to be a hard coded (defined) memory address of
+		     0x1FFF6B60. I'm not sure why it has to be hard coded,
+		     since its passed as a paramater (register) */
+		  "r"(ambebuffer_encode)
+		: "memory"
 	);
 
 	soundRetrieveBuffer();// gets currentWaveBuffer pointer used as input r2 to the encoder
 
-	r0 = (int)bitbuffer_encode;
-	r2 = (int)currentWaveBuffer;//tmp_wavbuffer;
-	r1 = (int)ambebuffer_encode;
-
 	asm volatile (
+		"MOV R0, %0\n"
+		"MOV R2, %1\n"
+		"MOV R1, %2\n"
 		"PUSH {R4-R11}\n"
 		"SUB SP, SP, #0x14\n"
 		"STR R1, [SP, #0x0C]\n"
@@ -146,12 +153,16 @@ void codecEncodeBlock(uint8_t *outdata_ptr)
 		"BL " QU(AMBE_ENCODE)
 		"ADD SP, SP, #0x14\n"
 		"POP {R4-R11}"
+		:
+		: "r"(bitbuffer_encode),
+		  "r"(currentWaveBuffer), //tmp_wavbuffer
+		  "r"(ambebuffer_encode)
+		: "memory"
 	);
 
-	r0 = (int)bitbuffer_encode;
-	r1 = (int)ambebuffer_encode_ecc;
-
 	asm volatile (
+		"MOV R0, %0\n"
+		"MOV R1, %1\n"
 		"PUSH {R4-R11}\n"
 		"SUB SP, SP, #0x14\n"
 		"MOV R3, R1\n"
@@ -160,6 +171,10 @@ void codecEncodeBlock(uint8_t *outdata_ptr)
 		"BL " QU(AMBE_ENCODE_ECC)
 		"ADD SP, SP, #0x14\n"
 		"POP {R4-R11}"
+		:
+		: "r"(bitbuffer_encode),
+		  "r"(ambebuffer_encode_ecc)
+		: "memory"
 	);
 
 	for (int i = 0; i < 72; i++)