/*
    romloader.cpp
    Copyright (C) 2007 Acekard, www.acekard.com
    Copyright (C) 2007-2009 somebody
    Copyright (C) 2009 yellow wood goblin

    SPDX-License-Identifier: GPL-3.0-or-later
*/

#include "romloader.h"
#include <fat.h>
#include <limits.h>
#include <nds.h>
#include <string.h>
#include "dbgtool.h"
//#include "akloader_arm7_bin.h"
//#include "akloader_arm9_bin.h"
#include "../../share/fifotool.h"
#include "globalsettings.h"
#include "savemngr.h"
#include "timetool.h"

// FIFO_CHANNEL_BITS - number of bits used to specify the channel in a packet - default=4
#define FIFO_CHANNEL_BITS 4
#define FIFO_CHANNEL_SHIFT (32 - FIFO_CHANNEL_BITS)
#define FIFO_IMMEDIATEBIT_SHIFT (FIFO_CHANNEL_SHIFT - 2)
#define FIFO_IMMEDIATEBIT (1 << FIFO_IMMEDIATEBIT_SHIFT)
#define FIFO_EXTRABIT_SHIFT (FIFO_CHANNEL_SHIFT - 3)
#define FIFO_EXTRABIT (1 << FIFO_EXTRABIT_SHIFT)
#define FIFO_VALUE32_MASK (FIFO_EXTRABIT - 1)

#define FIFO_PACK_VALUE32(channel, value32) \
    (((channel) << FIFO_CHANNEL_SHIFT) | FIFO_IMMEDIATEBIT | (((value32)) & FIFO_VALUE32_MASK))

static void resetAndLoop() {
    // Interrupt
    REG_IME = 0;
    REG_IE = 0;
    REG_IF = ~0;

    DC_FlushAll();
    DC_InvalidateAll();

    fifoSendValue32(FIFO_USER_01, MENU_MSG_ARM7_REBOOT);
    while (true) {
        while (REG_IPC_FIFO_CR & IPC_FIFO_RECV_EMPTY)
            ;
        u32 res = REG_IPC_FIFO_RX;
        if (FIFO_PACK_VALUE32(FIFO_USER_01, MENU_MSG_ARM7_READY_BOOT) == res) break;
    }

    swiSoftReset();
}

bool loadRom(const std::string& filename, const std::string& savename, u32 flags, long cheatOffset,
             size_t cheatSize) {
    *(u32*)0x23fd900 = flags;
    *(u32*)0x23fd904 = cheatOffset;
    *(u32*)0x23fd908 = cheatSize;
    memset((void*)0x23fda00, 0, PATH_MAX * 2);
    strcpy((char*)0x23fda00, filename.c_str());
    strcpy((char*)(0x23fda00 + PATH_MAX), savename.c_str());

    dbg_printf("load %s\n", filename.c_str());

    // copy loader's arm7 code
    //    memcpy( (void *)0x023FA000, akloader_arm7_bin, akloader_arm7_bin_size );
    __NDSHeader->arm7executeAddress = (void*)0x023FA000;

    // copy loader's arm9 code
    //    memcpy( (void *)0x023c0000, akloader_arm9_bin, akloader_arm9_bin_size );
    __NDSHeader->arm9executeAddress = (void*)0x023c0000;

    dbg_printf("load done\n");

    resetAndLoop();
    return true;
}