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

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

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

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

    //Check for RedNAND
    if(sdmmc_sdcard_readsectors(nandOffset + 1, 1, temp) == 0)
    {
        if(*(u32 *)(temp + 0x100) == NCSD_MAGIC)
        {
            *off = nandOffset + 1;
            *head = nandOffset + 1;
        }

        //Check for Gateway emuNAND
        else if(sdmmc_sdcard_readsectors(nandOffset + nandSize, 1, temp) == 0)
        {
            if(*(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)--;
                if(*emuNAND) getEmunandSect(off, head, emuNAND);

                return 0;
            }
        }
    }

    return 1;
}

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

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

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

    *readOff = (u32)memsearch(pos, pattern, size, 4) - 6;
    *writeOff = (u32)memsearch((u8 *)(*readOff + 0xA), pattern, 0x100, 4) - 6;
}

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

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

void *getEmuCode(u8 *proc9Offset)
{
    const u8 pattern[] = {0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0x00};

    //Looking for the last free space before Process9
    return memsearch(proc9Offset - 0x3000, pattern, 0x3000, 6) + 0x455;
}