diff options
Diffstat (limited to 'OvmfPkg/ResetVector')
| -rw-r--r-- | OvmfPkg/ResetVector/QemuDebugCon.asm | 36 | ||||
| -rw-r--r-- | OvmfPkg/ResetVector/ResetVector.nasmb | 4 |
2 files changed, 40 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
diff --git a/OvmfPkg/ResetVector/ResetVector.nasmb b/OvmfPkg/ResetVector/ResetVector.nasmb index 5832aaa8ab..366a70fb99 100644 --- a/OvmfPkg/ResetVector/ResetVector.nasmb +++ b/OvmfPkg/ResetVector/ResetVector.nasmb @@ -40,6 +40,10 @@ %include "Port80Debug.asm"
%elifdef DEBUG_SERIAL
%include "SerialDebug.asm"
+%elif 0
+; Set ^ this to 1 to enable postcodes on the qemu debug console.
+; Disabled by default because it is incompatible with SEV-ES/SEV-SNP and TDX.
+ %include "QemuDebugCon.asm"
%else
%include "DebugDisabled.asm"
%endif
|