fusee: remove unnecessary delay.

fusee/fusee-secondary/src/main.c

@@ -111,6 +111,9 @@ int main(int argc, void **argv) {
         
         print(SCREEN_LOG_LEVEL_MANDATORY, "Now performing nxboot.\n");
         uint32_t boot_memaddr = nxboot_main();
+        /* Wait for the splash screen to have been displayed as long as it should be. */
+        splash_screen_wait_delay();
+        /* Finish boot. */
         nxboot_finish(boot_memaddr);
     } else {
         /* TODO: What else do we want to do in terms of argc/argv? */

fusee/fusee-secondary/src/splash_screen.c

@@ -27,6 +27,8 @@
 #undef u8
 #undef u32
 
+static uint32_t g_splash_start_time = 0;
+
 static void render_bmp(const uint32_t *bmp_data, uint32_t *framebuffer, uint32_t bmp_width, uint32_t bmp_height, uint32_t bmp_pos_x, uint32_t bmp_pos_y) {
     /* Render the BMP. */
     for (uint32_t y = bmp_pos_y; y < (bmp_pos_y + bmp_height); y++) {
@@ -39,6 +41,11 @@ static void render_bmp(const uint32_t *bmp_data, uint32_t *framebuffer, uint32_t
     console_display(framebuffer);
 }
 
+void splash_screen_wait_delay(void) {
+    /* Ensure the splash screen is displayed for at least three seconds. */
+    udelay_absolute(g_splash_start_time, 3000000);
+}
+
 void display_splash_screen_bmp(const char *custom_splash_path, void *fb_address) {
     uint8_t *splash_screen = (uint8_t *)splash_screen_bmp;
     
@@ -84,7 +91,7 @@ void display_splash_screen_bmp(const char *custom_splash_path, void *fb_address)
     } else {
         fatal_error("Invalid splash screen format!\n");
     }
-
-    /* Display the splash screen for two and a half seconds. */
-    udelay(2500000);
+    
+    /* Note the time we started displaying the splash. */
+    g_splash_start_time = get_time_us();
 }

fusee/fusee-secondary/src/splash_screen.h

@@ -26,5 +26,6 @@
 #define SPLASH_SCREEN_SIZE_MAX      (SPLASH_SCREEN_HEIGHT_MAX * SPLASH_SCREEN_STRIDE * 4)
 
 void display_splash_screen_bmp(const char *custom_splash_path, void *fb_address);
+void splash_screen_wait_delay(void);
 
 #endif

fusee/fusee-secondary/src/timers.h

@@ -81,6 +81,13 @@ static inline void udelay(uint32_t usecs) {
     while (get_time_us() - start < usecs);
 }
 
+/**
+ * Delays until a number of usecs have passed since an absolute start time.
+ */
+static inline void udelay_absolute(uint32_t start, uint32_t usecs) {
+    while (get_time_us() - start < usecs);
+}
+
 /**
  * Delays for a given number of milliseconds.
  */