Now this compiles

gameGraphics.c

@@ -13,16 +13,19 @@
 // including the background and whatnot.
 void fullDrawGame(Game *game) {
   // TA-TODO: IMPLEMENT.
+  UNUSED(game);
 }
 
 // This function will be used to undraw (i.e. erase) things that might
 // move in a frame. E.g. in a Snake game, erase the Snake, the food & the score.
 void undrawGame(Game *game) {
   // TA-TODO: IMPLEMENT.
+  UNUSED(game);
 }
 
 // This function will be used to draw things that might have moved in a frame.
 // For example, in a Snake game, draw the snake, the food, the score.
 void drawGame(Game *game) {
   // TA-TODO: IMPLEMENT.
+  UNUSED(game);
 }

gameGraphics.h

@@ -1,3 +1,6 @@
+#ifndef GRAPHICS_SEEN
+#define GRAPHICS_SEEN
+
 #include "gameLogic.h"
 
 // This function will be used to draw everything about the game
@@ -14,3 +17,5 @@ void drawGame(Game *game);
 
 // If you have anything else you need accessible from outside the gameLogic.c
 // file, you can add them here. You likely won't.
+
+#endif

gameLogic.c

@@ -4,6 +4,7 @@ void initializeGame(Game* game) {
     // TA-TODO: Initialize everything that's part of this Game struct here.
     // Suppose the struct contains random values, make sure everything gets
     // the value it should have when the game begins.
+    UNUSED(game);
 }
 
 // TA-TODO: Add any process functions for sub-elements of your game here.
@@ -30,5 +31,7 @@ void processGame(Game *game, u32 keysPressedBefore, u32 keysPressedNow) {
    *
    * Do not do any drawing here.
    */
-
+   UNUSED(game);
+   UNUSED(keysPressedBefore);
+   UNUSED(keysPressedNow);
 }

gameLogic.h

@@ -1,3 +1,6 @@
+#ifndef LOGIC_SEEN
+#define LOGIC_SEEN
+
 #include "gba.h"
 
 typedef struct {
@@ -39,3 +42,5 @@ void processGame(Game *game, u32 keysPressedBefore, u32 keysPressedNow);
 
 // If you have anything else you need accessible from outside the gameLogic.c
 // file, you can add them here. You likely won't.
+
+#endif

gba.c

@@ -1,9 +1,9 @@
 #include "gba.h"
 
-u16 *videoBuffer = (u16 *)0x6000000;
+volatile unsigned short *videoBuffer = (u16 *)0x6000000;
 u32 vBlankCounter = 0;
 
-void waitForVBlank() {
+void waitForVBlank(void) {
   // TA-TODO: IMPLEMENT
 
   // Write a while loop that keeps going until we're NOT in vBlank anymore:
@@ -19,13 +19,7 @@ void waitForVBlank() {
 }
 
 static int __qran_seed= 42;
-static int sqran(int seed) {
-    int old= __qran_seed;
-    __qran_seed= seed;
-    return old;
-}
-
-static int qran() {
+static int qran(void) {
     __qran_seed= 1664525*__qran_seed+1013904223;
     return (__qran_seed>>16) & 0x7FFF;
 }
@@ -36,37 +30,52 @@ int randint(int min, int max) {
 
 void setPixel(int x, int y, u16 color) {
   // TA-TODO: IMPLEMENT
+  UNUSED(x);
+  UNUSED(y);
+  UNUSED(color);
 }
 
 void drawRectDMA(int x, int y, int width, int height, volatile u16 color) {
   // TA-TODO: IMPLEMENT
+  UNUSED(x);
+  UNUSED(y);
+  UNUSED(width);
+  UNUSED(height);
+  UNUSED(color);
 }
 
 void drawFullScreenImageDMA(u16 *image) {
   // TA-TODO: IMPLEMENT
+  UNUSED(image);
 }
 
 void drawImageDMA(int x, int y, int width, int height, u16 *image) {
   // TA-TODO: IMPLEMENT
+  UNUSED(x);
+  UNUSED(y);
+  UNUSED(width);
+  UNUSED(height);
+  UNUSED(image);
 }
 
 void fillScreenDMA(volatile u16 color) {
   // TA-TODO: IMPLEMENT
+  UNUSED(color);
 }
 
 void drawChar(int col, int row, char ch, u16 color) {
 	for(int r = 0; r<8; r++) {
 		for(int c=0; c<6; c++) {
 			if(fontdata_6x8[OFFSET(r, c, 6) + ch*48]) {
-				setPixel(videoBuffer, col+c, row+r, color);
+				setPixel(col+c, row+r, color);
 			}
 		}
 	}
 }
 
 void drawString(int col, int row, char *str, u16 color) {
 	while(*str) {
-		drawChar(videoBuffer, col, row, *str++, color);
+		drawChar(col, row, *str++, color);
 		col += 6;
 	}
 }
@@ -84,5 +93,5 @@ void drawCenteredString(int x, int y, int width, int height, char *str, u16 colo
 
     int col = x + ((width - strWidth) >> 1);
     int row = y + ((height - strHeight) >> 1);
-    drawString(videoBuffer, col, row, str, color);
+    drawString(col, row, str, color);
 }

gba.h

@@ -1,3 +1,6 @@
+#ifndef GBA_SEEN
+#define GBA_SEEN
+
 // ---------------------------------------------------------------------------
 //                       USEFUL TYPEDEFS
 // ---------------------------------------------------------------------------
@@ -112,12 +115,12 @@ extern u32 vblankCounter;
 /**
  * Runs a blocking loop until the start of next VBlank.
  */
-void waitForVBlank();
+void waitForVBlank(void);
 
 // ---------------------------------------------------------------------------
 //                       MISC
 // ---------------------------------------------------------------------------
-#define UNUSED_PARAM(param) ((void)((param)))
+#define UNUSED(param) ((void)((param)))
 
 /**
  * Generates a pseudo-random number between min and max, inclusive.
@@ -136,10 +139,12 @@ void drawRectDMA(int x, int y, int width, int height, volatile u16 color);
 void drawFullScreenImageDMA(u16 *image);
 void drawImageDMA(int x, int y, int width, int height, u16 *image);
 void fillScreenDMA(volatile u16 color);
-void drawChar(int x, int y, char ch, u16 color);
-void drawString(int x, int y, char *str, u16 color);
-void drawCenteredString(int x, int y, int width, int height, char *str, u16 color);
+void drawChar(int col, int row, char ch, u16 color);
+void drawString(int col, int row, char *str, u16 color);
+void drawCenteredString(int col, int row, int width, int height, char *str, u16 color);
 
 /** Contains the pixels of each character from a 6x8 font */
 // This is in the font.c file. You can replace the font if you want.
 extern const unsigned char fontdata_6x8[12288];
+
+#endif

main.c

@@ -18,7 +18,7 @@ typedef enum {
   GAMEOVER_NODRAW,
 } GBAState;
 
-int main() {
+int main(void) {
   GBAState state = START;
   Game game;
 
@@ -47,22 +47,22 @@ int main() {
         break;
       case GAME_INIT:
         // Initialize the game. Switch to the GAME state.
-        initializeGame(game);
+        initializeGame(&game);
 
         // Draw the initial state of the game
-        fullDrawGame(game);
+        fullDrawGame(&game);
 
         state = GAME;
         break;
       case GAME:
         // Un-draw any potentially moving elements of the game
-        undrawGame(game);
+        undrawGame(&game);
 
         // Process the game for one frame
-        processGame(game, previousButtons, currentButtons);
+        processGame(&game, previousButtons, currentButtons);
 
         // Draw the current state of the game
-        drawGame(game);
+        drawGame(&game);
 
         // Check if the game is over. If it is, then go to the gameover state.
         if (game.gameOver) state = GAMEOVER;