diff --git a/include/arm9/menu.h b/include/arm9/menu.h
index f00f514..4dbd2c4 100644
--- a/include/arm9/menu.h
+++ b/include/arm9/menu.h
@@ -65,7 +65,8 @@
 // This must be called once in each (sub-) menu iteration,
 // after menuUpdateGlobalState has been called.
 void menuActState(void);
-
+// Shows a windowed text, updates menu state.
 void menuPrintPrompt(const char *text);
+// Waits for any key being pressed, updates menu state.
 void menuWaitForAnyPadkey();
 
diff --git a/include/arm9/ui.h b/include/arm9/ui.h
index 98fbbe3..3f0415c 100644
--- a/include/arm9/ui.h
+++ b/include/arm9/ui.h
@@ -29,3 +29,4 @@
 void uiPrintBootWarning();
 void uiPrintBootFailure();
 bool uiCheckHomePressed(u32 msTimeout);
+void uiWaitForAnyPadkey();
diff --git a/source/arm9/console.c b/source/arm9/console.c
index 7c42884..95246b6 100644
--- a/source/arm9/console.c
+++ b/source/arm9/console.c
@@ -736,13 +736,6 @@
 	
 	int starty = (console->windowY - 1) * 8 - thickness;
 	int endy = console->windowHeight * 8 + thickness;
-	
-	/*
-	printf("startx: %i\n", startx);
-	printf("endx: %i\n", endx);
-	printf("endy: %i\n", endy);
-	printf("starty: %i\n", starty);
-	*/
 
 	u16 color = colorTable[colorIndex];
 	
diff --git a/source/arm9/main.c b/source/arm9/main.c
index 7999d5c..8c4b8ce 100644
--- a/source/arm9/main.c
+++ b/source/arm9/main.c
@@ -213,7 +213,7 @@
 		if(res[3] == FR_OK) uiPrintIfVerbose("%s\e[0m\n", res_str[1]);
 		else uiPrintIfVerbose("%s ERROR 0x%d\e[0m\n", res_str[0], res[3]);
 
-		finalRes &= res[3] == res[2] == res[1] == FR_OK;
+		finalRes &= ((res[3] == res[2]) == res[1]) == FR_OK;
 	}
 	else finalRes = false;
 
diff --git a/source/arm9/menu.c b/source/arm9/menu.c
index e5029d9..75660b8 100644
--- a/source/arm9/menu.c
+++ b/source/arm9/menu.c
@@ -73,15 +73,6 @@
 	uiPrintTextAt(1, 10, "Wifi flash status: %s\e[0m", nand_res[bootInfo.wififlash_status]);
 }
 
-static void rewindConsole()
-{
-	// get ready to repaint
-	consoleSelect(&con_top);
-	printf("\033[0;0H");	// set cursor to the upper left corner
-	consoleSelect(&con_bottom);
-	printf("\033[0;0H");
-}
-
 int enter_menu(int initial_state)
 {
 	u32 keys;
@@ -121,8 +112,6 @@
 				
 				hidScanInput();
 				keys = hidKeysDown();
-		
-				rewindConsole();
 				
 				menu_main_draw_top();
 			
@@ -206,7 +195,8 @@
 				goto exitAndLaunchFirm;
 				break;
 			
-			default: printf("OOPS!\n"); break;
+			/* this should never happen */
+			default: uiPrintIfVerbose("OOPS!\n"); break;
 		}
 
 		switch(menuUpdateGlobalState())
@@ -383,7 +373,8 @@
 
 void menuPrintPrompt(const char *text)
 {
-	printf(text);
+	// TODO: use uiShowMessageWindow
+	uiPrintInfo(text);
 }
 
 void menuWaitForAnyPadkey()
diff --git a/source/arm9/menu_filebrowse.c b/source/arm9/menu_filebrowse.c
index 9895eea..700bc7e 100644
--- a/source/arm9/menu_filebrowse.c
+++ b/source/arm9/menu_filebrowse.c
@@ -119,10 +119,10 @@
 {
 	// clear old '*' char
 	consoleSetCursor(&con_bottom, 0, (old_cursor_pos % (maxEntries)) + 1);
-	printf(" ");
+	uiPrintInfo(" ");
 	
 	consoleSetCursor(&con_bottom, 0, (cursor_pos % (maxEntries)) + 1);
-	printf("*");
+	uiPrintInfo("*");
 }
 
 static void updateScreen(int cursor_pos, bool dirChange)
@@ -151,9 +151,9 @@
 	
 	// print the current path in the first line
 	formatEntry(entry, curPath, (u32) maxLen - 3, false);
-	printf("%s :", entry);
+	uiPrintInfo("%s :", entry);
 	
-	if(cursor_pos < (u32) maxEntries)
+	if(cursor_pos < (int) maxEntries)
 	{
 		start = 0;
 		end = min(maxEntries, curEntriesCount);
@@ -167,7 +167,7 @@
 	for(unsigned i = start; i < end; i++)
 	{
 		formatEntry(entry, dirEntries[i].name, (u32) maxLen - 2, true);
-		printf("\n%s %s", i == (unsigned) cursor_pos ? "*" : " ", entry);
+		uiPrintInfo("\n%s %s", i == (unsigned) cursor_pos ? "*" : " ", entry);
 	}
 }
 
diff --git a/source/arm9/menu_firmloader.c b/source/arm9/menu_firmloader.c
index c4e2721..9f07452 100644
--- a/source/arm9/menu_firmloader.c
+++ b/source/arm9/menu_firmloader.c
@@ -33,7 +33,7 @@
 	uiClearConsoles();
 	consoleSelect(&con_top);
 	
-	printf("FIRM Loader\n\n");
+	uiPrintCenteredInLine(1, "FIRM Loader");
 
 	menuUpdateGlobalState();
 	
@@ -41,8 +41,8 @@
 	{
 		if(!quick)
 		{
-			printf("\n\x1B[31mBad firmware.\e[0m\n\n");
-			printf("Press any key...\n");
+			uiPrintError("Bad firmware.\n");
+			uiPrintInfo("Press any key...\n");
 			
 			menuWaitForAnyPadkey();
 		}
@@ -51,7 +51,7 @@
 	
 	firmLoaded = 1;
 	
-	printf("\n\x1B[32mFirmware verification SUCCESS!\e[0m\n\n");
+	uiPrint("Firmware verification SUCCESS!", 32, true);
 	
 	menuSetReturnToState(MENU_STATE_EXIT);
 	
@@ -59,7 +59,7 @@
 
 fail:
 	
-	printf("FIRM-Launch aborted.\n");
+	uiPrintCenteredInLine(25, "FIRM-Launch aborted.");
 	
 	TIMER_sleep(500);
 	
@@ -149,13 +149,13 @@
 		if(path)
 		{
 			if(fromMenu)
-				printf("\nBoot Option #%i:\n%s\n", i + 1, path);
+				uiPrintInfo("Boot Option #%i:\n%s\n", i + 1, path);
 			
 			// check if fw still exists
 			if(!statFirmware(path))
 			{
 				if(fromMenu)
-					printf("Couldn't find firmware...\n");
+					uiPrintInfo("Couldn't find firmware...\n");
 				goto try_next;
 			}
 			
@@ -171,8 +171,8 @@
 				{
 					if(fromMenu)
 					{
-						printf("Skipping, right buttons are not pressed.\n");
-						printf("%" PRIX32 " %" PRIX32 "\n", padValue, expectedPadValue);
+						uiPrintInfo("Skipping, right buttons are not pressed.\n");
+						uiPrintInfo("%" PRIX32 " %" PRIX32 "\n", padValue, expectedPadValue);
 					}
 					goto try_next;
 				}
@@ -239,7 +239,7 @@
 
 	if(f_stat(filePath, &fileStat) != FR_OK)
 	{
-		printf("Failed to get file status!\n");
+		uiPrintInfo("Failed to get file status!\n");
 		return 0;
 	}
 
@@ -247,7 +247,7 @@
 
 	if(f_open(&file, filePath, FA_READ) != FR_OK)
 	{
-		printf("Failed to open '%s'!\n", filePath);
+		uiPrintInfo("Failed to open '%s'!\n", filePath);
 		return 0;
 	}
 
@@ -259,7 +259,7 @@
 
 	if(f_read(&file, (u8*)FIRM_LOAD_ADDR, fileSize, &bytesRead) != FR_OK)
 	{
-		printf("Failed to read from file!\n");
+		uiPrintInfo("Failed to read from file!\n");
 		fileSize = 0;
 	}
 
diff --git a/source/arm9/menu_options.c b/source/arm9/menu_options.c
index bdfaecf..2305e18 100644
--- a/source/arm9/menu_options.c
+++ b/source/arm9/menu_options.c
@@ -69,7 +69,7 @@
 		{
 			if(i<OptionCount)
 			{
-				printf("%s %s", i == curOptionIndex ? "*" : " ", optionStrings[i]);
+				uiPrintInfo("%s %s", i == curOptionIndex ? "*" : " ", optionStrings[i]);
 				rewindConsoleX();
 			
 				if(subOptionsActive && i == curOptionIndex)
@@ -77,10 +77,10 @@
 					for(unsigned int j=0; j<curSubOptionCount; j++)
 					{
 						if(curSubOptionHighlighted && j == curHighlightedSubOptionIndex)
-							printf(" %s  \x1B[33m%s\e[0m", j == curSubOptionIndex ? "*" : " ",
+							uiPrintInfo(" %s  \x1B[33m%s\e[0m", j == curSubOptionIndex ? "*" : " ",
 															optionSubStrings[j]);
 						else
-							printf(" %s  %s", j == curSubOptionIndex ? "*" : " ", optionSubStrings[j]);
+							uiPrintInfo(" %s  %s", j == curSubOptionIndex ? "*" : " ", optionSubStrings[j]);
 						rewindConsoleX();
 					}
 				}
@@ -215,7 +215,7 @@
 void rewindConsoleX(void)
 {
 	unsigned int len = con_bottom.windowWidth - con_bottom.cursorX;
-	while(len--) printf(" ");
+	while(len--) uiPrintInfo(" ");
 	
 	consoleSetCursor(&con_bottom, consoleX, con_bottom.cursorY + 1);
 }
@@ -231,7 +231,7 @@
 	}
 	else
 	{
-		u32 *mode = (u32 *)configGetData(KBootMode);
+		const u32 *mode = (const u32 *)configGetData(KBootMode);
 		if(mode)
 		{
 			curHighlightedSubOptionIndex = *mode;
@@ -289,7 +289,7 @@
 		
 		if(path)
 		{
-			if(ret = validateNandImage(path))
+			if((ret = validateNandImage(path)) != 0)
 			{
 				switch(ret)
 				{
@@ -302,6 +302,8 @@
 					case NANDIMG_ERROR_NCONTS:
 						menuPrintPrompt("NAND Image file is not continuous!\n");
 						break;
+					default:
+						break;
 				}
 			}
 			else configSetKeyData(key, path);
diff --git a/source/arm9/menu_update.c b/source/arm9/menu_update.c
index d61910f..7a0a5c1 100644
--- a/source/arm9/menu_update.c
+++ b/source/arm9/menu_update.c
@@ -22,7 +22,7 @@
 
 bool menuUpdateLoader()
 {
-	u8 *updateBuffer = (u8 *) FIRM_LOAD_ADDR;
+	u32 *updateBuffer = (u32 *) FIRM_LOAD_ADDR;
 	FILINFO fileStat;
 	size_t fwSize;
 	size_t index;
@@ -56,14 +56,14 @@
 	}
 	
 	// verify fastboot magic
-	if(memcmp(updateBuffer+0x208, "FASTBOOT 3DS   ", 0x10) != 0)
+	if(memcmp((void*)updateBuffer+0x208, "FASTBOOT 3DS   ", 0x10) != 0)
 	{
 		uiPrintError("Not an update file!\n");
 		goto fail;
 	}
 	
 	/* check version */
-	u32 updateVersion = *(u32 *)(updateBuffer + 0x218);
+	u32 updateVersion = *(u32 *)((void*)updateBuffer + 0x218);
 	
 	if(updateVersion < BOOTLOADER_VERSION)
 	{
diff --git a/source/arm9/nandimage.c b/source/arm9/nandimage.c
index 205775a..7db252d 100644
--- a/source/arm9/nandimage.c
+++ b/source/arm9/nandimage.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "arm9/nandimage.h"
 #include "fatfs/ff.h"
 #include "util.h"