1 files changed, 36 insertions, 0 deletions
diff --git a/OvmfPkg/ResetVector/QemuDebugCon.asm b/OvmfPkg/ResetVector/QemuDebugCon.asm
new file mode 100644
index 0000000000..8729fc2ffc
--- /dev/null
+++ b/OvmfPkg/ResetVector/QemuDebugCon.asm
@@ -0,0 +1,36 @@
+;------------------------------------------------------------------------------
+; @file
+; qemu debug console support macros (based on serial port macros)
+;
+; Copyright (c) 2008 - 2018, Intel Corporation. All rights reserved.<BR>
+; Copyright (c) 2024, Red Hat, Inc.<BR>
+; SPDX-License-Identifier: BSD-2-Clause-Patent
+;
+;------------------------------------------------------------------------------
+
+%macro  debugShowCharacter 1
+    mov     dx, 0x402
+    mov     al, %1
+    out     dx, al
+%endmacro
+
+%macro  debugShowHexDigit 1
+  %if (%1 < 0xa)
+    debugShowCharacter BYTE ('0' + (%1))
+  %else
+    debugShowCharacter BYTE ('a' + ((%1) - 0xa))
+  %endif
+%endmacro
+
+%macro  debugShowPostCode 1
+    debugShowHexDigit (((%1) >> 4) & 0xf)
+    debugShowHexDigit ((%1) & 0xf)
+    debugShowCharacter `\r`
+    debugShowCharacter `\n`
+%endmacro
+
+BITS    16
+
+%macro  debugInitialize 0
+    ; not required
+%endmacro