// uefi_textout.c : prints some text on the screen.
//
// (c) Ulf Frisk, 2017
// Author: Ulf Frisk, pcileech@frizk.net
//
// compile with:
// cl.exe /O1 /Os /Oy /FD /MT /GS- /J /GR- /FAcs /W4 /Zl /c /TC /kernel uefi_common.c
// cl.exe /O1 /Os /Oy /FD /MT /GS- /J /GR- /FAcs /W4 /Zl /c /TC /kernel uefi_textout.c
// ml64.exe uefi_common_a.asm /Feuefi_textout.exe /link /NODEFAULTLIB /RELEASE /MACHINE:X64 /entry:main uefi_textout.obj uefi_common.obj
// shellcode64.exe -o uefi_textout.exe "UEFI TEST PROGRAM - PRINT STUFF ON THE SCREEN\n===========================================================\nSyntax: pcileech.exe uefi_textout\nOptions (optional): \ntext: -s <text to print>\nposition: -0 1 -1 <x_pos> -2 <y_pos>\nnumber of runs (default=1): -3 <number>\nGENERAL INFORMATION BELOW:\n  TEXT      : %s\n"
//
#include "uefi_common.h"

VOID c_EntryPoint(PKMDDATA pk)
{
	WCHAR szPrint[MAX_PATH];
	CHAR *szSrc, szPrintDefault[] = { ' ', ' ', ' ', ' ', 'U', 'E', 'F', 'I', ' ', 'E', 'V', 'I', 'L', ' ', 'F', 'R', 'O', 'M', ' ', 'P', 'C', 'I', 'L', 'E', 'E', 'C', 'H', '!', ' ', ' ', ' ' , ' ', 0 };
	EFI_GUID GUID_EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL = EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL_GUID;
	EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL oOut;
	EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL *pOut = &oOut;
	QWORD i, efi_status;
	szSrc = pk->dataInStr[0] ? pk->dataInStr : szPrintDefault;
	for(i = 0; i < MAX_PATH - 1; i++) {
		// read overflow here if default, but doesn't matter...
		szPrint[i] = szSrc[i];
		pk->dataOutStr[i] = szSrc[i];
	}
	pk->dataOut[0] = efi_status = LocateProtocol(&GUID_EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL, NULL, (QWORD**)&pOut);
	if(!efi_status) {
		if(pk->dataIn[0]) {
			pOut->SetCursorPosition((QWORD*)pOut, pk->dataIn[1], pk->dataIn[2]);
		}
		pOut->SetAttribute((QWORD*)pOut, EFI_BACKGROUND_RED | EFI_CYAN);
		for(i = 0; i < max(1, pk->dataIn[3]); i++) {
			pOut->OutputString((QWORD*)pOut, szPrint);
		}
	}
}