23333333

Author: UEFI-code

MonikaDriver-Win10/Gidget.asm

@@ -1,3 +1,11 @@
+KI_USER_SHARED_DATA equ 0FFFFF78000000000h
+SharedSystemTime equ KI_USER_SHARED_DATA + 14h
+
+.data
+
+AccuTimeBuf:
+    buffer db 8 dup(0);
+
 .code _text
 
 NopToy PROC PUBLIC
@@ -8,4 +16,47 @@ ret
 
 NopToy ENDP
 
+MonikaDelayMsNative PROC PUBLIC
+
+push rcx; // backup goal parameter
+
+;before we call stupid NT API, we should prepare a safer stack buffer
+push rbp;
+mov rbp, rsp;
+sub rsp, 128; // fly away 128 bytes
+;Query Current Time
+mov rcx, AccuTimeBuf
+call KeQuerySystemTime;
+;Now we can partly restore the stack
+mov rsp, rbp;
+mov rax, [AccuTimeBuf];
+push rax; // push the current time to stack
+mov rbp, rsp;
+
+WaitLoop:
+hlt;
+;Before we call stupid NT API, we should prepare a safer stack buffer
+sub rsp, 128; // fly away 128 bytes
+;Query Current Time
+mov rcx, AccuTimeBuf
+call KeQuerySystemTime;
+;Now we can partly restore the stack
+mov rsp, rbp;
+mov rax, [AccuTimeBuf]; Current Time
+pop rbx; The Initial Time
+add rsp, 8; skip the orignal rbp bakup
+pop rcx; The Goal delay
+; Now we should put rsp to a right place
+sub rsp, 8 + 8 + 8
+sub rax, rbx; The Time Difference
+cmp rax, rcx;
+jb WaitLoop;
+
+add rsp, 8
+pop rbp;
+add rsp, 8
+ret
+
+MonikaDelayMsNative ENDP
+
 END