main.cpp

#include <cstdio>
#include <string>
#include <3ds.h>
#include "fs.h"
#include "misc.h"


u8 sysLang = 0;


// Override the default service init/exit functions
extern "C"
{
	u32 __stacksize__ = 0x40000;

	void __appInit()
	{
		// Initialize services
		srvInit();
		aptInit();
		gfxInit(GSP_RGB565_OES, GSP_RGB565_OES, false);
		hidInit(NULL);
		fsInit();
		sdmcArchiveInit();
	}


	void __appExit()
	{
		// Exit services
		sdmcArchiveExit();
		fsExit();
		hidExit();
		gfxExit();
		aptExit();
		srvExit();
	}
}


Result _srvGetServiceHandle(Handle* out, const char* name)
{
  Result rc = 0;

	u32* cmdbuf = getThreadCommandBuffer();
	cmdbuf[0] = 0x50100;
	strcpy((char*)&cmdbuf[1], name);
	cmdbuf[3] = strlen(name);
	cmdbuf[4] = 0;

	if((rc = svcSendSyncRequest(*srvGetSessionHandle()))) return rc;

	*out = cmdbuf[3];
	return cmdbuf[1];
}


void callback(const std::u16string& fsObject, u32 totalPercent, u32 filePercent)
{
	Buffer<char> str(256);
	utf16_to_utf8((u8*)&str, (u16*)fsObject.c_str(), 255);
	printf("\x1b[1;0H%s %u%%\nTotal: %u", &str, filePercent, totalPercent);

	gfxFlushBuffers();
	gfxSwapBuffers();
}


int main()
{
	Handle fsUHandle = 0;
	Result res = _srvGetServiceHandle(&fsUHandle, "fs:USER"); // Get a handle for the process we run under

	consoleInit(GFX_TOP, nullptr);
	printf("Get fs:USER handle: 0x%X\n", res);
	res = FSUSER_Initialize(&fsUHandle);
	printf("FSUSER_Initialize: 0x%X\n", res);


	FS_archive saveArchive = {ARCH_SAVEDATA, {PATH_EMPTY, 0, nullptr}};
	res = FSUSER_OpenArchive(&fsUHandle, &saveArchive);
	printf("Open archive: 0x%X\n", res);

	if(!res) printf("\x1b[2JA Backup save data.\nB Import save data.\nX Exit.");
	else
	{
		printf("Could not access the savedata archive! Press X to exit.\n");
		while(true)
		{
			hidScanInput();
			if(hidKeysDown() & KEY_X) goto exit;
		}
	}

	while(aptMainLoop())
	{
		hidScanInput();

		u32 kDown = hidKeysDown();

		if(kDown & KEY_A)
		{
			try
			{
				printf("\x1b[2JBacking up save data...");
				fs::copyDir(fsUHandle, *fsGetSessionHandle(), u"/", u"/saveDataBackup", callback, saveArchive);
				printf("\x1b[2JA Backup save data.\nB Import save data.\nX Exit.");
			}
			catch(std::exception& e)
			{
				printf("\n%s\n", e.what());
			}
		}
		if(kDown & KEY_B)
		{
			try
			{
				printf("\x1b[2JRestoring save data...");
				fs::copyDir(*fsGetSessionHandle(), fsUHandle, u"/saveDataBackup", u"/", callback, sdmcArchive, saveArchive);
				res = FSUSER_ControlArchive(fsUHandle, &saveArchive);
				printf("Control archive: 0x%X\n", res);
				printf("\x1b[2JA Backup save data.\nB Import save data.\nX Exit.");
			}
			catch(std::exception& e)
			{
				printf("\n%s\n", e.what());
			}
		}
		if(kDown & KEY_X) break;

		gfxFlushBuffers();
		gfxSwapBuffers();
		gspWaitForVBlank();
	}

	exit:

	FSUSER_CloseArchive(&fsUHandle, &saveArchive);
  svcCloseHandle(fsUHandle);

	return 0;
}

Hello,
I'm relatively new to the 3DS hacking/homebrew scene. I know about derKitPro and <3ds.h>, but what about "fs.h" and "misc.h"? where do they come from?