/*
*   patches.c
*/

#include "patches.h"
#include "memory.h"

/**************************************************
*                   Patches
**************************************************/

const u32 mpuPatch[3] = {0x00360003, 0x00200603, 0x001C0603};

const u16 nandRedir[2] = {0x4C00, 0x47A0},
          sigPatch[2] = {0x2000, 0x4770},
          writeBlock[2] = {0x2000, 0x46C0},
          writeBlockSafe[2] = {0x2400, 0xE01D};

/**************************************************
*                   Functions
**************************************************/

u8 *getProcess9(u8 *pos, u32 size, u32 *process9Size, u32 *process9MemAddr)
{
    u8 *off = memsearch(pos, "ess9", size, 4);

    *process9Size = *(u32 *)(off - 0x100) * 0x200;
    *process9MemAddr = *(u32 *)(off + 0xC);

    //Process9 code offset (start of NCCH + ExeFS offset + ExeFS header size)
    return off - 0x204 + (*(u32 *)(off - 0x64) * 0x200) + 0x200;
}

void getSigChecks(u8 *pos, u32 size, u32 *off, u32 *off2)
{
    //Look for signature checks
    const u8 pattern[] = {0xC0, 0x1C, 0x76, 0xE7},
             pattern2[] = {0xB5, 0x22, 0x4D, 0x0C};

    *off = (u32)memsearch(pos, pattern, size, 4);
    *off2 = (u32)memsearch(pos, pattern2, size, 4) - 1;
}

void *getReboot(u8 *pos, u32 size, u32 process9MemAddr, u32 *fOpenOffset)
{
    //Look for FIRM reboot code
    const u8 pattern[] = {0xDE, 0x1F, 0x8D, 0xE2};

    u8 *off = memsearch(pos, pattern, size, 4) - 0x10;

    //Firmlaunch function offset - offset in BLX opcode (A4-16 - ARM DDI 0100E) + 1
    *fOpenOffset = (u32)(off + 9 - (-((*(u32 *)off & 0x00FFFFFF) << 2) & 0xFFFFF) - pos + process9MemAddr);

    return off;
}

u16 *getFirmWrite(u8 *pos, u32 size)
{
    //Look for FIRM writing code
    u8 *const off = memsearch(pos, "exe:", size, 4);
    const u8 pattern[] = {0x00, 0x28, 0x01, 0xDA};

    return (u16 *)memsearch(off - 0x100, pattern, 0x100, 4);
}

u16 *getFirmWriteSafe(u8 *pos, u32 size)
{
    //Look for FIRM writing code
    const u8 pattern[] = {0x04, 0x1E, 0x1D, 0xDB};

    return (u16 *)memsearch(pos, pattern, size, 4);
}

u32 getLoader(u8 *pos, u32 *loaderSize)
{
    u8 *off = pos;
    u32 size;

    while(1)
    {
        size = *(u32 *)(off + 0x104) * 0x200;
        if(*(u32 *)(off + 0x200) == 0x64616F6C) break;
        off += size;
    }

    *loaderSize = size;

    return (u32)(off - pos);
}

u32 *getExceptionVectorsPage(u8 *pos, u32 size)
{
    const u8 pattern[] = {0x00, 0xB0, 0x9C, 0xE5};
    
    return (u32 *)(memsearch(pos, pattern, size, 4) - 0x2C);
}