#include "types.h"
#include "elf_abi.h"
#include "kexploit.h"
#include "structs.h"
#include "sd_loader.h"
#include "coreinit.h"

#define MEM_BASE                                        0xC0800000
#include "common.h"
#include "os_defs.h"

//! this shouldnt depend on OS
#define LIB_CODE_RW_BASE_OFFSET                         0xC1000000
#define CODE_RW_BASE_OFFSET                             0xC0000000
#define DATA_RW_BASE_OFFSET                             0xC0000000

#define ADDRESS_OSTitle_main_entry_ptr                  0x1005E040
#define ADDRESS_main_entry_hook                         0x0101C56C

#define ROOTRPX_DBAT0U_VAL                              0xC00003FF
#define COREINIT_DBAT0U_VAL                             0xC20001FF

#define ROOTRPX_DBAT0L_VAL                              0x30000012
#define COREINIT_DBAT0L_VAL                             0x32000012

/* Install functions */
static void InstallMain(private_data_t *private_data);
static void InstallPatches(private_data_t *private_data);
static void ExitFailure(private_data_t *private_data, const char *failure);

static void SetupKernelSyscall(unsigned int addr);
static void KernelCopyData(unsigned int addr, unsigned int src, unsigned int len);

/* assembly functions */
extern void SC_0x25_KernelCopyData(void* addr, void* src, unsigned int len);
extern void Syscall_0x36(void);
extern void KernelPatches(void);

/* ****************************************************************** */
/*                               ENTRY POINT                          */
/* ****************************************************************** */
void __main(void)
{
	/* Quit ongoing menu load music */
	unsigned int sound_handle = 0;
	OSDynLoad_Acquire("snd_core.rpl", &sound_handle);
	void (* AXInit)();
	void (* AXQuit)();
	OSDynLoad_FindExport(sound_handle, 0, "AXInit", &AXInit);
	OSDynLoad_FindExport(sound_handle, 0, "AXQuit", &AXQuit);
	AXInit();
	AXQuit();

    /* Get coreinit handle and keep it in memory */
    unsigned int coreinit_handle;
    OSDynLoad_Acquire("coreinit.rpl", &coreinit_handle);

    /* Get our memory functions */
    unsigned int* functionPointer;
    void* (*p_memset)(void * dest, unsigned int value, unsigned int bytes);
    OSDynLoad_FindExport(coreinit_handle, 0, "memset", &p_memset);

    private_data_t private_data;
    p_memset(&private_data, 0, sizeof(private_data_t));

    private_data.coreinit_handle = coreinit_handle;
    private_data.memset = p_memset;
    private_data.data_elf = (unsigned char *) sd_loader_sd_loader_elf; // use this address as temporary to load the elf

    OSDynLoad_FindExport(coreinit_handle, 1, "MEMAllocFromDefaultHeapEx", &functionPointer);
    private_data.MEMAllocFromDefaultHeapEx = (void*(*)(unsigned int, unsigned int))*functionPointer;
    OSDynLoad_FindExport(coreinit_handle, 1, "MEMFreeToDefaultHeap", &functionPointer);
    private_data.MEMFreeToDefaultHeap = (void (*)(void *))*functionPointer;

    OSDynLoad_FindExport(coreinit_handle, 0, "memcpy", &private_data.memcpy);
    OSDynLoad_FindExport(coreinit_handle, 0, "OSEffectiveToPhysical", &private_data.OSEffectiveToPhysical);
    OSDynLoad_FindExport(coreinit_handle, 0, "DCFlushRange", &private_data.DCFlushRange);
    OSDynLoad_FindExport(coreinit_handle, 0, "ICInvalidateRange", &private_data.ICInvalidateRange);
    OSDynLoad_FindExport(coreinit_handle, 0, "_Exit", &private_data._Exit);

	/* do kernel exploit if needed */
    if (private_data.OSEffectiveToPhysical((void *)0xa0000000) == (void *)0)
        run_kexploit(&private_data);

    /* setup kernel copy data syscall */
    kern_write((void*)(KERN_SYSCALL_TBL_2 + (0x25 * 4)), (unsigned int)KernelCopyData);

    /* Install our code now */
    InstallMain(&private_data);

    /* setup our own syscall and call it */
    SetupKernelSyscall((unsigned int)KernelPatches);
    Syscall_0x36();

    /* Patch functions and our code for usage */
    InstallPatches(&private_data);

	/* Exit our core 0 thread to return to main */
	void (*OSExitThread)(int);
	OSDynLoad_FindExport(coreinit_handle, 0, "OSExitThread", &OSExitThread);
	OSExitThread(0);
}

void ExitFailure(private_data_t *private_data, const char *failure)
{
    /************************************************************************/
    // Prepare screen
    void (*OSScreenInit)();
    unsigned int (*OSScreenGetBufferSizeEx)(unsigned int bufferNum);
    unsigned int (*OSScreenSetBufferEx)(unsigned int bufferNum, void * addr);
    unsigned int (*OSScreenClearBufferEx)(unsigned int bufferNum, unsigned int temp);
    unsigned int (*OSScreenFlipBuffersEx)(unsigned int bufferNum);
    unsigned int (*OSScreenPutFontEx)(unsigned int bufferNum, unsigned int posX, unsigned int posY, const char * buffer);

    OSDynLoad_FindExport(private_data->coreinit_handle, 0, "OSScreenInit", &OSScreenInit);
    OSDynLoad_FindExport(private_data->coreinit_handle, 0, "OSScreenGetBufferSizeEx", &OSScreenGetBufferSizeEx);
    OSDynLoad_FindExport(private_data->coreinit_handle, 0, "OSScreenSetBufferEx", &OSScreenSetBufferEx);
    OSDynLoad_FindExport(private_data->coreinit_handle, 0, "OSScreenClearBufferEx", &OSScreenClearBufferEx);
    OSDynLoad_FindExport(private_data->coreinit_handle, 0, "OSScreenFlipBuffersEx", &OSScreenFlipBuffersEx);
    OSDynLoad_FindExport(private_data->coreinit_handle, 0, "OSScreenPutFontEx", &OSScreenPutFontEx);

    // Prepare screen
    int screen_buf0_size = 0;
    int screen_buf1_size = 0;
    unsigned int screen_color = 0; // (r << 24) | (g << 16) | (b << 8) | a;

    // Init screen and screen buffers
    OSScreenInit();
    screen_buf0_size = OSScreenGetBufferSizeEx(0);
    screen_buf1_size = OSScreenGetBufferSizeEx(1);
    OSScreenSetBufferEx(0, (void *)0xF4000000);
    OSScreenSetBufferEx(1, (void *)0xF4000000 + screen_buf0_size);

    // Clear screens
    OSScreenClearBufferEx(0, screen_color);
    OSScreenClearBufferEx(1, screen_color);

    // Flush the cache
    private_data->DCFlushRange((void *)0xF4000000, screen_buf0_size);
    private_data->DCFlushRange((void *)0xF4000000 + screen_buf0_size, screen_buf1_size);

    // Flip buffers
    OSScreenFlipBuffersEx(0);
    OSScreenFlipBuffersEx(1);

    OSScreenPutFontEx(1, 0, 0, failure);

    OSScreenFlipBuffersEx(1);
    OSScreenClearBufferEx(1, 0);

    unsigned int t1 = 0x3FFFFFFF;
    while(t1--) asm volatile("nop");

    private_data->_Exit(0);
}

/* *****************************************************************************
 * Base functions
 * ****************************************************************************/
static void SetupKernelSyscall(unsigned int address)
{
    // Add syscall #0x36
    kern_write((void*)(KERN_SYSCALL_TBL_2 + (0x36 * 4)), address);

    // make kern_read/kern_write available in all places
    kern_write((void*)(KERN_SYSCALL_TBL_1 + (0x34 * 4)), KERN_CODE_READ);
    kern_write((void*)(KERN_SYSCALL_TBL_2 + (0x34 * 4)), KERN_CODE_READ);
    kern_write((void*)(KERN_SYSCALL_TBL_3 + (0x34 * 4)), KERN_CODE_READ);
    kern_write((void*)(KERN_SYSCALL_TBL_4 + (0x34 * 4)), KERN_CODE_READ);

    kern_write((void*)(KERN_SYSCALL_TBL_1 + (0x35 * 4)), KERN_CODE_WRITE);
    kern_write((void*)(KERN_SYSCALL_TBL_2 + (0x35 * 4)), KERN_CODE_WRITE);
    kern_write((void*)(KERN_SYSCALL_TBL_3 + (0x35 * 4)), KERN_CODE_WRITE);
    kern_write((void*)(KERN_SYSCALL_TBL_4 + (0x35 * 4)), KERN_CODE_WRITE);
}

static void KernelCopyData(unsigned int addr, unsigned int src, unsigned int len)
{
    /*
     * Setup a DBAT access for our 0xC0800000 area and our 0xBC000000 area which hold our variables like GAME_LAUNCHED and our BSS/rodata section
     */
    register unsigned int dbatu0, dbatl0, target_dbat0u, target_dbat0l;
    // setup mapping based on target address
    if ((addr >= 0xC0000000) && (addr < 0xC2000000)) // root.rpx address
    {
        target_dbat0u = ROOTRPX_DBAT0U_VAL;
        target_dbat0l = ROOTRPX_DBAT0L_VAL;
    }
    else if ((addr >= 0xC2000000) && (addr < 0xC3000000))
    {
        target_dbat0u = COREINIT_DBAT0U_VAL;
        target_dbat0l = COREINIT_DBAT0L_VAL;
    }
    // save the original DBAT value
    asm volatile("mfdbatu %0, 0" : "=r" (dbatu0));
    asm volatile("mfdbatl %0, 0" : "=r" (dbatl0));
    asm volatile("mtdbatu 0, %0" : : "r" (target_dbat0u));
    asm volatile("mtdbatl 0, %0" : : "r" (target_dbat0l));
    asm volatile("eieio; isync");

    unsigned char *src_p = (unsigned char*)src;
    unsigned char *dst_p = (unsigned char*)addr;

    unsigned int i;
    for(i = 0; i < len; i++)
    {
        dst_p[i] = src_p[i];
    }

    unsigned int flushAddr = addr & ~31;

    while(flushAddr < (addr + len))
    {
        asm volatile("dcbf 0, %0; sync" : : "r"(flushAddr));
        flushAddr += 0x20;
    }

    /*
     * Restore original DBAT value
     */
    asm volatile("mtdbatu 0, %0" : : "r" (dbatu0));
    asm volatile("mtdbatl 0, %0" : : "r" (dbatl0));
    asm volatile("eieio; isync");
}

static int strcmp(const char *s1, const char *s2)
{
    while(*s1 && *s2)
    {
        if(*s1 != *s2) {
            return -1;
        }
        s1++;
        s2++;
    }

    if(*s1 != *s2) {
        return -1;
    }
    return 0;
}

static unsigned int get_section(private_data_t *private_data, unsigned char *data, const char *name, unsigned int * size, unsigned int * addr, int fail_on_not_found)
{
    Elf32_Ehdr *ehdr = (Elf32_Ehdr *) data;

    if (   !data
        || !IS_ELF (*ehdr)
        || (ehdr->e_type != ET_EXEC)
        || (ehdr->e_machine != EM_PPC))
    {
        ExitFailure(private_data, "Invalid elf file");
    }

    Elf32_Shdr *shdr = (Elf32_Shdr *) (data + ehdr->e_shoff);
    int i;
    for(i = 0; i < ehdr->e_shnum; i++)
    {
        const char *section_name = ((const char*)data) + shdr[ehdr->e_shstrndx].sh_offset + shdr[i].sh_name;
        if(strcmp(section_name, name) == 0)
        {
            if(addr)
                *addr = shdr[i].sh_addr;
            if(size)
                *size = shdr[i].sh_size;
            return shdr[i].sh_offset;
        }
    }

    if(fail_on_not_found)
        ExitFailure(private_data, (char*)name);

    return 0;
}

/* ****************************************************************** */
/*                         INSTALL MAIN CODE                          */
/* ****************************************************************** */
static void InstallMain(private_data_t *private_data)
{
    // get .text section
    unsigned int main_text_addr = 0;
    unsigned int main_text_len = 0;
    unsigned int section_offset = get_section(private_data, private_data->data_elf, ".text", &main_text_len, &main_text_addr, 1);
    unsigned char *main_text = private_data->data_elf + section_offset;
    /* Copy main .text to memory */
    if(section_offset > 0)
        SC_0x25_KernelCopyData((void*)(CODE_RW_BASE_OFFSET + main_text_addr), main_text, main_text_len);

    // get the .rodata section
    unsigned int main_rodata_addr = 0;
    unsigned int main_rodata_len = 0;
    section_offset = get_section(private_data, private_data->data_elf, ".rodata", &main_rodata_len, &main_rodata_addr, 0);
    if(section_offset > 0)
    {
        unsigned char *main_rodata = private_data->data_elf + section_offset;
        /* Copy main rodata to memory */
        SC_0x25_KernelCopyData((void*)(DATA_RW_BASE_OFFSET + main_rodata_addr), main_rodata, main_rodata_len);
    }

    // get the .data section
    unsigned int main_data_addr = 0;
    unsigned int main_data_len = 0;
    section_offset = get_section(private_data, private_data->data_elf, ".data", &main_data_len, &main_data_addr, 0);
    if(section_offset > 0)
    {
        unsigned char *main_data = private_data->data_elf + section_offset;
        /* Copy main data to memory */
        SC_0x25_KernelCopyData((void*)(DATA_RW_BASE_OFFSET + main_data_addr), main_data, main_data_len);
    }

    // get the .bss section
    unsigned int main_bss_addr = 0;
    unsigned int main_bss_len = 0;
    section_offset = get_section(private_data, private_data->data_elf, ".bss", &main_bss_len, &main_bss_addr, 0);
    if(section_offset > 0)
    {
        unsigned char *main_bss = private_data->data_elf + section_offset;
        /* Copy main data to memory */
        SC_0x25_KernelCopyData((void*)(DATA_RW_BASE_OFFSET + main_bss_addr), main_bss, main_bss_len);
    }
}

/* ****************************************************************** */
/*                         INSTALL PATCHES                            */
/* All OS specific stuff is done here                                 */
/* ****************************************************************** */
static void InstallPatches(private_data_t *private_data)
{
    OsSpecifics osSpecificFunctions;
    private_data->memset(&osSpecificFunctions, 0, sizeof(OsSpecifics));

    unsigned int bufferU32;
    /* Pre-setup a few options to defined values */
    bufferU32 = VER;
    SC_0x25_KernelCopyData((void*)&OS_FIRMWARE, &bufferU32, sizeof(bufferU32));
    bufferU32 = 0xDEADC0DE;
    SC_0x25_KernelCopyData((void*)&MAIN_ENTRY_ADDR, &bufferU32, sizeof(bufferU32));
    SC_0x25_KernelCopyData((void*)&ELF_DATA_ADDR, &bufferU32, sizeof(bufferU32));
    bufferU32 = 0;
    SC_0x25_KernelCopyData((void*)&ELF_DATA_SIZE, &bufferU32, sizeof(bufferU32));

    unsigned int jump_main_hook = 0;
    osSpecificFunctions.addr_OSDynLoad_Acquire = (unsigned int)OSDynLoad_Acquire;
    osSpecificFunctions.addr_OSDynLoad_FindExport = (unsigned int)OSDynLoad_FindExport;

    osSpecificFunctions.addr_KernSyscallTbl1 = KERN_SYSCALL_TBL_1;
    osSpecificFunctions.addr_KernSyscallTbl2 = KERN_SYSCALL_TBL_2;
    osSpecificFunctions.addr_KernSyscallTbl3 = KERN_SYSCALL_TBL_3;
    osSpecificFunctions.addr_KernSyscallTbl4 = KERN_SYSCALL_TBL_4;
    osSpecificFunctions.addr_KernSyscallTbl5 = KERN_SYSCALL_TBL_5;
    //! pointer to main entry point of a title
    osSpecificFunctions.addr_OSTitle_main_entry = ADDRESS_OSTitle_main_entry_ptr;

    SC_0x25_KernelCopyData((void*)OS_SPECIFICS, &osSpecificFunctions, sizeof(OsSpecifics));

    //! at this point we dont need to check header and stuff as it is sure to be OK
    Elf32_Ehdr *ehdr = (Elf32_Ehdr *) private_data->data_elf;
    unsigned int mainEntryPoint = ehdr->e_entry;

    //! Install our entry point hook
    unsigned int repl_addr = ADDRESS_main_entry_hook;
    unsigned int jump_addr = mainEntryPoint & 0x03fffffc;
    bufferU32 = 0x48000003 | jump_addr;
    SC_0x25_KernelCopyData((void*)(LIB_CODE_RW_BASE_OFFSET + repl_addr), &bufferU32, sizeof(bufferU32));
    // flush caches and invalidate instruction cache
    private_data->ICInvalidateRange((void*)(repl_addr), 4);
}