Added access to NVRAM to M: drive

arm9/source/system/spiflash.c

@@ -0,0 +1,89 @@
+/*
+ *   This file is part of fastboot 3DS
+ *   Copyright (C) 2017 derrek, profi200
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "common.h"
+#include "spiflash.h"
+
+
+#define SPI_REGS_BUS2_BASE  (0x10000000 + 0x100000 + 0x60000)
+#define REG_SPI_BUS2_CNT    *((vu16*)(SPI_REGS_BUS2_BASE + 0x00))
+#define REG_SPI_BUS2_DATA   *((vu8* )(SPI_REGS_BUS2_BASE + 0x02))
+
+
+
+static void spi_busy_wait()
+{
+    while(REG_SPI_BUS2_CNT & 0x80);
+}
+
+static void spi_put_byte(u8 data)
+{
+    REG_SPI_BUS2_DATA = data;
+    spi_busy_wait();
+}
+
+static u8 spi_receive_byte()
+{
+    // clock out a dummy byte
+    REG_SPI_BUS2_DATA = 0x00;
+    spi_busy_wait();
+    return REG_SPI_BUS2_DATA;
+}
+
+// select spiflash if select=true, deselect otherwise 
+static void spiflash_select(bool select)
+{
+    // select device 1, enable SPI bus
+    REG_SPI_BUS2_CNT = 0x8100 | (select << 11);
+}
+
+bool spiflash_get_status()
+{
+    u8 resp;
+
+    spi_busy_wait();
+    spiflash_select(1);
+    spi_put_byte(SPIFLASH_CMD_RDSR);
+    spiflash_select(0);
+    resp = spi_receive_byte();
+
+    if(resp & 1) return false;
+    return true;
+}
+
+void spiflash_read(u32 offset, u32 size, u8 *buf)
+{
+	spi_busy_wait();
+	spiflash_select(1);
+	spi_put_byte(SPIFLASH_CMD_READ);
+	
+	// write addr (24-bit, msb first)	
+	for(int i=0; i<3; i++)
+	{
+		offset <<= 8;
+		spi_put_byte((offset >> 24) & 0xFF);
+	}
+	
+	// read bytes
+	for(u32 i=0; i<size; i++)
+		buf[i] = spi_receive_byte();
+	
+	// end of read
+	spiflash_select(0);
+	spi_receive_byte();
+}

arm9/source/system/spiflash.h

@@ -0,0 +1,32 @@
+#pragma once
+
+/*
+ *   This file is part of fastboot 3DS
+ *   Copyright (C) 2017 derrek, profi200
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "common.h"
+
+
+#define NVRAM_SIZE  0x20000 // 1 Mbit (128kiB)  
+#define SPIFLASH_CMD_RDSR  (0x05)
+#define SPIFLASH_CMD_READ  (0x03)
+
+
+
+// true if spiflash is installed, false otherwise
+bool spiflash_get_status();
+void spiflash_read(u32 offset, u32 size, u8 *buf);

arm9/source/virtual/vmem.c

@@ -5,6 +5,7 @@
 #include "keydb.h"
 #include "sdmmc.h"
 #include "itcm.h"
+#include "spiflash.h"
 #include "i2c.h"
 
 #define VFLAG_CALLBACK      (1UL<<27)
@@ -46,17 +47,20 @@ enum VMemCallbackType {
     VMEM_CALLBACK_OTP_DECRYPTED,
     VMEM_CALLBACK_MCU_REGISTERS,
     VMEM_CALLBACK_FLASH_CID,
+    VMEM_CALLBACK_NVRAM,
     VMEM_NUM_CALLBACKS
 };
 
 ReadVMemFileCallback ReadVMemOTPDecrypted;
 ReadVMemFileCallback ReadVMemMCURegisters;
 ReadVMemFileCallback ReadVMemFlashCID;
+ReadVMemFileCallback ReadVMemNVRAM;
 
 static ReadVMemFileCallback* const vMemCallbacks[] = {
     ReadVMemOTPDecrypted,
     ReadVMemMCURegisters,
-    ReadVMemFlashCID
+    ReadVMemFlashCID,
+    ReadVMemNVRAM
 };
 STATIC_ASSERT(sizeof(vMemCallbacks) / sizeof(vMemCallbacks[0]) == VMEM_NUM_CALLBACKS);
 
@@ -83,7 +87,8 @@ static const VirtualFile vMemFileTemplates[] = {
     { "mcu_3ds_regs.mem" , VMEM_CALLBACK_MCU_REGISTERS, 0x00000100, I2C_DEV_MCU, VFLAG_CALLBACK | VFLAG_READONLY },
     { "mcu_dsi_regs.mem" , VMEM_CALLBACK_MCU_REGISTERS, 0x00000100, I2C_DEV_POWER, VFLAG_CALLBACK | VFLAG_READONLY },
     { "sd_cid.mem"       , VMEM_CALLBACK_FLASH_CID    , 0x00000010, 0x00, VFLAG_CALLBACK | VFLAG_READONLY },
-    { "nand_cid.mem"     , VMEM_CALLBACK_FLASH_CID    , 0x00000010, 0x01, VFLAG_CALLBACK | VFLAG_READONLY }
+    { "nand_cid.mem"     , VMEM_CALLBACK_FLASH_CID    , 0x00000010, 0x01, VFLAG_CALLBACK | VFLAG_READONLY },
+    { "nvram.mem"        , VMEM_CALLBACK_NVRAM        , NVRAM_SIZE, 0x00, VFLAG_CALLBACK | VFLAG_READONLY }
 };
 
 bool ReadVMemDir(VirtualFile* vfile, VirtualDir* vdir) { // uses a generic vdir object generated in virtual.c
@@ -156,6 +161,20 @@ int ReadVMemFlashCID(const VirtualFile* vfile, void* buffer, u64 offset, u64 cou
     return 0;
 }
 
+// Read NVRAM.
+int ReadVMemNVRAM(const VirtualFile* vfile, void* buffer, u64 offset, u64 count) {
+    static bool wififlash_initialized = false;
+    (void) vfile;
+    
+    if (!wififlash_initialized) {
+        wififlash_initialized = spiflash_get_status();
+        if (!wififlash_initialized) return 1;
+    }
+    
+    spiflash_read((u32) offset, (u32) count, buffer);
+    return 0;
+}
+
 int ReadVMemFile(const VirtualFile* vfile, void* buffer, u64 offset, u64 count) {
     if (vfile->flags & VFLAG_CALLBACK) {
         if ((offset + count > vfile->size) || (0u + offset + count < offset))