From 005f75bd61d9c1cf08d702dbae6ff4b38ab089ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herm=C3=A8s=20B=C3=A9lusca-Ma=C3=AFto?=
 <hermes.belusca-maito@reactos.org>
Date: Sat, 19 Apr 2025 18:00:12 +0200
Subject: [PATCH] [RTL] x64/ARM: Alias RtlpBreakWithStatusInstruction to
 DbgBreakPointWithStatus; x64: fix a bug.

RtlpBreakWithStatusInstruction is just a label for KD.

On machines that have register calling conventions (basically all except
x86), the `Status` parameter for `DbgBreakPointWithStatus` is stored in
the first argument register.

https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/wdm/nf-wdm-dbgbreakpointwithstatus

On the x64 platform, `DbgBreakPointWithStatus` only uses the ECX register
and leaves EAX untouched. Verified on Windows.
---
 sdk/lib/rtl/amd64/debug_asm.S | 21 +++++++--------------
 sdk/lib/rtl/arm/debug_asm.S   |  6 +-----
 2 files changed, 8 insertions(+), 19 deletions(-)

diff --git a/sdk/lib/rtl/amd64/debug_asm.S b/sdk/lib/rtl/amd64/debug_asm.S
index 00cbe7163bd..7db8e89d122 100644
--- a/sdk/lib/rtl/amd64/debug_asm.S
+++ b/sdk/lib/rtl/amd64/debug_asm.S
@@ -8,37 +8,29 @@
 
 #include <asm.inc>
 
-/* GLOBALS ****************************************************************/
-
-PUBLIC DbgBreakPoint
-PUBLIC DbgBreakPointWithStatus
-PUBLIC DbgUserBreakPoint
-PUBLIC DebugService
-PUBLIC DebugService2
-PUBLIC RtlpBreakWithStatusInstruction
-
 /* FUNCTIONS ***************************************************************/
 
 .code64
 
+PUBLIC DbgUserBreakPoint
 DbgUserBreakPoint:
+PUBLIC DbgBreakPoint
 .PROC DbgBreakPoint
     .endprolog
     int 3
     ret
 .ENDP
 
+PUBLIC RtlpBreakWithStatusInstruction
+RtlpBreakWithStatusInstruction:
+PUBLIC DbgBreakPointWithStatus
 .PROC DbgBreakPointWithStatus
-    .endprolog
-    mov eax, ecx
-.ENDP
-
-.PROC RtlpBreakWithStatusInstruction
     .endprolog
     int 3
     ret
 .ENDP
 
+PUBLIC DebugService2
 DebugService2:
 
     /* Pass the service number in eax */
@@ -56,6 +48,7 @@ DebugService2:
  *     IN PVOID Argument1,  // <r9>  = [rsp + 32]
  *     IN PVOID Argument2); //         [rsp + 40]
  */
+PUBLIC DebugService
 DebugService:
 
     /* Prepare registers for interrupt */
diff --git a/sdk/lib/rtl/arm/debug_asm.S b/sdk/lib/rtl/arm/debug_asm.S
index c223edcb344..21e21269020 100644
--- a/sdk/lib/rtl/arm/debug_asm.S
+++ b/sdk/lib/rtl/arm/debug_asm.S
@@ -21,11 +21,7 @@
     LEAF_END DbgUserBreakPoint
 
     LEAF_ENTRY DbgBreakPointWithStatus
-    __debugbreak
-    bx lr
-    LEAF_END
-
-    LEAF_ENTRY RtlpBreakWithStatusInstruction
+    ALTERNATE_ENTRY RtlpBreakWithStatusInstruction
     __debugbreak
     bx lr
     LEAF_END