Switch to Normmatt's iodelay

Seems to be more reliable in all conditions

loader/source/fatfs/sdmmc/delay.h

@@ -6,4 +6,4 @@
 
 #include "common.h"
 
-void waitcycles(u32 us);
+void ioDelay(u32 us);

loader/source/fatfs/sdmmc/delay.s

@@ -1,10 +1,17 @@
+// Copyright 2014 Normmatt
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
 .arm
-.global waitcycles
-.type   waitcycles STT_FUNC
+.global ioDelay
+.type   ioDelay STT_FUNC
 
-@waitcycles ( u32 us )
-waitcycles:
-    waitcycles_loop:
-        subs r0, #1
-        bgt waitcycles_loop
-    bx lr
+@ioDelay ( u32 us )
+ioDelay:
+	ldr r1, =0x18000000  @ VRAM
+1:
+	@ Loop doing uncached reads from VRAM to make loop timing more reliable
+	ldr r2, [r1]
+	subs r0, #1
+	bgt 1b
+	bx lr

loader/source/fatfs/sdmmc/sdmmc.c

@@ -286,7 +286,7 @@ static void InitSD()
 static int Nand_Init()
 {
     inittarget(&handleNAND);
-    waitcycles(0xF000);
+    ioDelay(0xF000);
 
     sdmmc_send_command(&handleNAND,0,0);
 
@@ -337,7 +337,7 @@ static int SD_Init()
 {
     inittarget(&handleSD);
 
-    waitcycles(1u << 18); //Card needs a little bit of time to be detected, it seems
+    ioDelay(1u << 18); //Card needs a little bit of time to be detected, it seems
 
     //If not inserted
     if (!(*((vu16*)0x1000601c) & TMIO_STAT0_SIGSTATE)) return -1;

source/fatfs/sdmmc/delay.h

@@ -6,4 +6,4 @@
 
 #include "common.h"
 
-void waitcycles(u32 us);
+void ioDelay(u32 us);

source/fatfs/sdmmc/delay.s

@@ -1,10 +1,17 @@
+// Copyright 2014 Normmatt
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
 .arm
-.global waitcycles
-.type   waitcycles STT_FUNC
+.global ioDelay
+.type   ioDelay STT_FUNC
 
-@waitcycles ( u32 us )
-waitcycles:
-    waitcycles_loop:
-        subs r0, #1
-        bgt waitcycles_loop
-    bx lr
+@ioDelay ( u32 us )
+ioDelay:
+	ldr r1, =0x18000000  @ VRAM
+1:
+	@ Loop doing uncached reads from VRAM to make loop timing more reliable
+	ldr r2, [r1]
+	subs r0, #1
+	bgt 1b
+	bx lr

source/fatfs/sdmmc/sdmmc.c

@@ -286,7 +286,7 @@ static void InitSD()
 static int Nand_Init()
 {
     inittarget(&handleNAND);
-    waitcycles(0xF000);
+    ioDelay(0xF000);
 
     sdmmc_send_command(&handleNAND,0,0);
 
@@ -337,7 +337,7 @@ static int SD_Init()
 {
     inittarget(&handleSD);
 
-    waitcycles(1u << 18); //Card needs a little bit of time to be detected, it seems
+    ioDelay(1u << 18); //Card needs a little bit of time to be detected, it seems
 
     //If not inserted
     if (!(*((vu16*)0x1000601c) & TMIO_STAT0_SIGSTATE)) return -1;