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Luma3DS-3GX/source/emunand.c
2016-09-06 15:52:08 +02:00

130 lines
4.3 KiB
C

/*
* This file is part of Luma3DS
* Copyright (C) 2016 Aurora Wright, TuxSH
*
* 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/>.
*
* Additional Terms 7.b of GPLv3 applies to this file: Requiring preservation of specified
* reasonable legal notices or author attributions in that material or in the Appropriate Legal
* Notices displayed by works containing it.
*/
#include "emunand.h"
#include "memory.h"
#include "fatfs/sdmmc/sdmmc.h"
#include "../build/emunandpatch.h"
void locateEmuNand(u32 *off, u32 *head, FirmwareSource *emuNand)
{
static u8 temp[0x200];
const u32 nandSize = getMMCDevice(0)->total_size;
u32 nandOffset = *emuNand == FIRMWARE_EMUNAND ? 0 :
(nandSize > 0x200000 ? 0x400000 : 0x200000);
//Check for RedNAND
if(!sdmmc_sdcard_readsectors(nandOffset + 1, 1, temp) &&
*(u32 *)(temp + 0x100) == NCSD_MAGIC)
{
*off = nandOffset + 1;
*head = nandOffset + 1;
}
//Check for Gateway emuNAND
else if(!sdmmc_sdcard_readsectors(nandOffset + nandSize, 1, temp) &&
*(u32 *)(temp + 0x100) == NCSD_MAGIC)
{
*off = nandOffset;
*head = nandOffset + nandSize;
}
/* Fallback to the first emuNAND if there's no second one,
or to SysNAND if there isn't any */
else
{
*emuNand = (*emuNand == FIRMWARE_EMUNAND2) ? FIRMWARE_EMUNAND : FIRMWARE_SYSNAND;
if(*emuNand) locateEmuNand(off, head, emuNand);
}
}
static inline u8 *getFreeK9Space(u8 *pos, u32 size)
{
const u8 pattern[] = {0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00};
//Looking for the last free space before Process9
return memsearch(pos + 0x13500, pattern, size - 0x13500, sizeof(pattern)) + 0x455;
}
static inline u32 getSdmmc(u8 *pos, u32 size)
{
//Look for struct code
const u8 pattern[] = {0x21, 0x20, 0x18, 0x20};
const u8 *off = memsearch(pos, pattern, size, sizeof(pattern));
return *(u32 *)(off + 9) + *(u32 *)(off + 0xD);
}
static inline void patchNandRw(u8 *pos, u32 size, u32 branchOffset)
{
const u16 nandRedir[2] = {0x4C00, 0x47A0};
//Look for read/write code
const u8 pattern[] = {0x1E, 0x00, 0xC8, 0x05};
u16 *readOffset = (u16 *)memsearch(pos, pattern, size, sizeof(pattern)) - 3,
*writeOffset = (u16 *)memsearch((u8 *)(readOffset + 5), pattern, 0x100, sizeof(pattern)) - 3;
*readOffset = nandRedir[0];
readOffset[1] = nandRedir[1];
((u32 *)readOffset)[1] = branchOffset;
*writeOffset = nandRedir[0];
writeOffset[1] = nandRedir[1];
((u32 *)writeOffset)[1] = branchOffset;
}
static inline void patchMpu(u8 *pos, u32 size)
{
//Look for MPU pattern
const u8 pattern[] = {0x03, 0x00, 0x24, 0x00};
u32 *off = (u32 *)memsearch(pos, pattern, size, sizeof(pattern));
off[0] = 0x00360003;
off[6] = 0x00200603;
off[9] = 0x001C0603;
}
void patchEmuNand(u8 *arm9Section, u32 arm9SectionSize, u8 *process9Offset, u32 process9Size, u32 emuHeader, u32 branchAdditive)
{
//Copy emuNAND code
u8 *freeK9Space = getFreeK9Space(arm9Section, arm9SectionSize);
memcpy(freeK9Space, emunand, emunand_size);
//Add the data of the found emuNAND
u32 *posOffset = (u32 *)memsearch(freeK9Space, "NAND", emunand_size, 4),
*posHeader = (u32 *)memsearch(freeK9Space, "NCSD", emunand_size, 4);
*posOffset = emuOffset;
*posHeader = emuHeader;
//Find and add the SDMMC struct
u32 *posSdmmc = (u32 *)memsearch(freeK9Space, "SDMC", emunand_size, 4);
*posSdmmc = getSdmmc(process9Offset, process9Size);
//Add emuNAND hooks
u32 branchOffset = (u32)freeK9Space - branchAdditive;
patchNandRw(process9Offset, process9Size, branchOffset);
//Set MPU for emu code region
patchMpu(arm9Section, arm9SectionSize);
}