Unrestrict - parental control remover for Nintendo 3DS

unrestrict.c

#include <3ds.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

void __system_allocateHeaps(void)
{
    extern char* fake_heap_start;
    extern char* fake_heap_end;
    
    extern u32 __ctru_heap;
    extern u32 __ctru_heap_size;
    extern u32 __ctru_linear_heap;
    extern u32 __ctru_linear_heap_size;
    
    u32 tmp = 0;
    
    // Distribute available memory into halves, aligning to page size.
    //u32 size = (osGetMemRegionFree(MEMREGION_SYSTEM) / 2) & 0xFFFFF000;
    __ctru_heap_size = 0x130000;
    __ctru_linear_heap_size = 0x780000; 
    
    //*(u32*)0x00100998 = size;
    
    
    // Allocate the application heap
    __ctru_heap = 0x08000000;
    svcControlMemory(&tmp, __ctru_heap, 0x0, __ctru_heap_size, (MemOp)MEMOP_ALLOC, (MemPerm)(MEMPERM_READ | MEMPERM_WRITE));
    
    // Allocate the linear heap
    //__ctru_linear_heap = 0x14000000;
    //svcControlMemory(&tmp, 0x1C000000 - __ctru_linear_heap_size, 0x0, __ctru_linear_heap_size, (MemOp)MEMOP_FREE, (MemPerm)(0));
    Result res = svcControlMemory(&__ctru_linear_heap, 0x0, 0x0, __ctru_linear_heap_size, (MemOp)MEMOP_ALLOC_LINEAR, (MemPerm)(MEMPERM_READ | MEMPERM_WRITE));
    if(res < 0) *(u32*)0x00100070 = res;
    if(__ctru_linear_heap < 0x10000000) *(u32*)0x00100071 = __ctru_linear_heap;
    
    // Set up newlib heap
    fake_heap_start = (char*)__ctru_heap;
    fake_heap_end = fake_heap_start + __ctru_heap_size;
}

Handle mcuHandle = 0;

Result mcuInit()
{
    return srvGetServiceHandle(&mcuHandle, "mcu::HWC");
}

Result mcuExit()
{
    return svcCloseHandle(mcuHandle);
}

Result mcuReadRegister(u8 reg, u8* data, u32 size)
{
    u32* ipc = getThreadCommandBuffer();
    ipc[0] = 0x10082;
    ipc[1] = reg;
    ipc[2] = size;
    ipc[3] = size << 4 | 0xC;
    ipc[4] = data;
    Result ret = svcSendSyncRequest(mcuHandle);
    if(ret < 0) return ret;
    return ipc[1];
}

Result mcuWriteRegister(u8 reg, u8* data, u32 size)
{
    u32* ipc = getThreadCommandBuffer();
    ipc[0] = 0x20082;
    ipc[1] = reg;
    ipc[2] = size;
    ipc[3] = size << 4 | 0xA;
    ipc[4] = data;
    Result ret = svcSendSyncRequest(mcuHandle);
    if(ret < 0) return ret;
    return ipc[1];
}

int main()
{
    gfxInit(GSP_RGB565_OES, GSP_RGB565_OES, false);
    
    PrintConsole console;
    consoleInit(GFX_BOTTOM, &console);
    
    puts("Unrestrict by Sono (C) 2017");
    
    Result res = 0;
    
    do
    {
        Handle h = 0;
        res = srvGetServiceHandle(&h, "cfg:s");
        if(res < 0) res = srvGetServiceHandle(&h, "cfg:i");
        if(res < 0)
        {
            printf("GetServiceHandle: %08X\n", res);
            break;
        }
        
        u32* ipc = getThreadCommandBuffer();
        ipc[0] = 0x40F0000;
        res = svcSendSyncRequest(h);
        if(res < 0)
        {
            printf("SendSyncRequest1: %08X\n", res);
            svcCloseHandle(h);
            break;
        }
        res = ipc[1];
        if(res < 0)
        {
            printf("IPC1: %08X\n", res);
            svcCloseHandle(h);
            break;
        }
        ipc[0] = 0x4030000;
        res = svcSendSyncRequest(h);
        if(res < 0)
        {
            printf("SendSyncRequest2: %08X\n", res);
            svcCloseHandle(h);
            break;
        }
        res = ipc[1];
        if(res < 0)
        {
            printf("IPC2: %08X\n", res);
            svcCloseHandle(h);
            break;
        }
        svcCloseHandle(h);
        
        res = 0;
        /*res = -1;//mcuInit();
        if(res >= 0)
        {
            u8 val = 2;
            mcuWriteRegister(0x20, &val, 1);
            mcuExit();
        }
        else printf("Failed to reboot: %08X\n", res);*/
    }
    while(0);
    
    if(res >= 0) goto ded;
    
    puts("An error occurred, press SELECT to exit");
    while(aptMainLoop())
    {
        hidScanInput();
        if(hidKeysHeld() & KEY_SELECT) break;
        gfxFlushBuffers();
        gspWaitForVBlank();
    }
    
    ded:
    
    gfxExit();
    
    return 0;
}