From 2e9659e36ab22883c0ff00a11626d6ae02b3e16b Mon Sep 17 00:00:00 2001
From: d0k3 <tore.anon@gmail.com>
Date: Tue, 16 May 2017 23:14:28 +0200
Subject: [PATCH] Improved unit detection routines

---
 source/common/platform.c | 15 ---------------
 source/common/platform.h |  8 --------
 source/common/unittype.h | 13 +++++++++++++
 source/nand/nand.c       |  6 +++---
 source/nand/nand.h       |  4 ++--
 5 files changed, 18 insertions(+), 28 deletions(-)
 delete mode 100644 source/common/platform.c
 delete mode 100644 source/common/platform.h
 create mode 100644 source/common/unittype.h

diff --git a/source/common/platform.c b/source/common/platform.c
deleted file mode 100644
index b56ef46..0000000
--- a/source/common/platform.c
+++ /dev/null
@@ -1,15 +0,0 @@
-#include "common.h"
-#include "platform.h"
-
-#define CONFIG_PLATFORM_REG ((volatile u32*)0x10140FFC)
-
-Platform GetUnitPlatform()
-{
-    switch (*CONFIG_PLATFORM_REG) {
-        case 7:
-            return PLATFORM_N3DS;
-        case 1:
-        default:
-            return PLATFORM_3DS;
-    }
-}
diff --git a/source/common/platform.h b/source/common/platform.h
deleted file mode 100644
index ce04df1..0000000
--- a/source/common/platform.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#pragma once
-
-typedef enum {
-    PLATFORM_3DS,
-    PLATFORM_N3DS,
-} Platform;
-
-Platform GetUnitPlatform();
diff --git a/source/common/unittype.h b/source/common/unittype.h
new file mode 100644
index 0000000..98dfa7f
--- /dev/null
+++ b/source/common/unittype.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include "common.h"
+
+// see: https://3dbrew.org/wiki/CONFIG11_Registers
+#define IS_O3DS     ((*(vu32*) 0x10140FFC) != 0x7)
+
+// see: https://www.3dbrew.org/wiki/Memory_layout#ARM9_ITCM
+// see: https://www.3dbrew.org/wiki/OTP_Registers#Plaintext_OTP
+#define IS_DEVKIT   ((*(vu8*) (0x01FFB800+0x19)) != 0x0)
+
+// see: https://3dbrew.org/wiki/CONFIG11_Registers
+#define IS_A9LH     ((*(vu32*) 0x101401C0) == 0)
diff --git a/source/nand/nand.c b/source/nand/nand.c
index 60c6965..761e982 100644
--- a/source/nand/nand.c
+++ b/source/nand/nand.c
@@ -326,7 +326,7 @@ u32 CheckNandHeader(void* header)
     // header type check
     u8* header_enc = header;
     if (memcmp(header_enc + 0x100, nand_magic_n3ds, sizeof(nand_magic_n3ds) == 0) == 0)
-        return (GetUnitPlatform() == PLATFORM_3DS) ? 0 : NAND_TYPE_N3DS;
+        return (IS_O3DS) ? 0 : NAND_TYPE_N3DS;
     else if (memcmp(header_enc + 0x100, nand_magic_o3ds, sizeof(nand_magic_o3ds) == 0) == 0)
         return NAND_TYPE_O3DS;
     
@@ -338,12 +338,12 @@ u32 CheckNandType(void)
     if (ReadNandSectors(NAND_BUFFER, 0, 1, 0xFF) != 0)
         return 0;
     if (memcmp(NAND_BUFFER + 0x100, nand_magic_n3ds, 0x60) == 0) {
-        return (GetUnitPlatform() == PLATFORM_3DS) ? 0 : NAND_TYPE_N3DS;
+        return (IS_O3DS) ? 0 : NAND_TYPE_N3DS;
     } else if (memcmp(NAND_BUFFER + 0x100, nand_magic_o3ds, 0x60) == 0) {
         u8 magic[8] = {0xE9, 0x00, 0x00, 0x43, 0x54, 0x52, 0x20, 0x20};
         if (ReadNandSectors(NAND_BUFFER, 0x5CAE5, 1, 0x04) != 0)
             return 0;
-        return ((GetUnitPlatform() == PLATFORM_3DS) || (memcmp(magic, NAND_BUFFER, 8) == 0)) ?
+        return ((IS_O3DS) || (memcmp(magic, NAND_BUFFER, 8) == 0)) ?
             NAND_TYPE_O3DS : NAND_TYPE_NO3DS;
     }
     
diff --git a/source/nand/nand.h b/source/nand/nand.h
index c204294..cc34423 100644
--- a/source/nand/nand.h
+++ b/source/nand/nand.h
@@ -1,9 +1,9 @@
 #pragma once
 
 #include "common.h"
-#include "platform.h"
+#include "unittype.h"
 
-#define NAND_MIN_SECTORS ((GetUnitPlatform() == PLATFORM_N3DS) ? NAND_MIN_SECTORS_N3DS : NAND_MIN_SECTORS_O3DS)
+#define NAND_MIN_SECTORS ((!IS_O3DS) ? NAND_MIN_SECTORS_N3DS : NAND_MIN_SECTORS_O3DS)
 
 #define NAND_SYSNAND    (1<<0)
 #define NAND_ZERONAND   (1<<3)