Luma3DS-3GX/source/emunand.c

/*
*   emunand.c
*       by Reisyukaku / Aurora Wright
*   Copyright (c) 2016 All Rights Reserved
*/

#include "emunand.h"
#include "memory.h"
#include "fatfs/sdmmc/sdmmc.h"

void getEmunandSect(u32 *off, u32 *head, u32 emuNAND){
    u8 *const temp = (u8 *)0x24300000;

    u32 nandSize = getMMCDevice(0)->total_size;
    u32 nandOffset = emuNAND == 1 ? 0 :
                                  (nandSize > 0x200000 ? 0x400000 : 0x200000);

    //Check for Gateway emuNAND
    if(sdmmc_sdcard_readsectors(nandOffset + nandSize, 1, temp) == 0){
        if(*(u32 *)(temp + 0x100) == NCSD_MAGIC){
                *off = nandOffset;
                *head = nandOffset + nandSize;
        }
        //Check for RedNAND
        else if(sdmmc_sdcard_readsectors(nandOffset + 1, 1, temp) == 0){
            if(*(u32 *)(temp + 0x100) == NCSD_MAGIC){
                *off = nandOffset + 1;
                *head = nandOffset + 1;
            }
            //Fallback to the first emuNAND if there's no second one
            else if(emuNAND == 2) getEmunandSect(off, head, 1);
        }
    }
}

u32 getSDMMC(void *pos, u32 size){
    //Look for struct code
    const u8 pattern[] = {0x21, 0x20, 0x18, 0x20};
    const u8 *off = (u8 *)memsearch(pos, pattern, size, 4) - 1;

    return *(u32 *)(off + 0x0A) + *(u32 *)(off + 0x0E);
}

void getEmuRW(void *pos, u32 size, u32 *readOff, u32 *writeOff){
    //Look for read/write code
    const u8 pattern[] = {0x1E, 0x00, 0xC8, 0x05};

    *writeOff = (u32)memsearch(pos, pattern, size, 4) - 6;
    *readOff = (u32)memsearch((void *)(*writeOff - 0x1000), pattern, 0x1000, 4) - 6;
}

u32 *getMPU(void *pos, u32 size){
    //Look for MPU pattern
    const u8 pattern[] = {0x03, 0x00, 0x24, 0x00};

    return (u32 *)memsearch(pos, pattern, size, 4);
}

void *getEmuCode(u8 *pos, u32 size, u8 *proc9Offset){
    const u8 pattern[] = {0x00, 0xFF, 0xFF, 0xFF};
 
    //Looking for the last free space before Process9
    return (u8 *)memsearch(pos, pattern, size - (size - (u32)(proc9Offset - pos)), 4) + 0xD;
}