1 files changed, 114 insertions, 0 deletions
diff --git a/OvmfPkg/ResetVector/SerialDebug.asm b/OvmfPkg/ResetVector/SerialDebug.asm
new file mode 100644
index 0000000000..2959fa5450
--- /dev/null
+++ b/OvmfPkg/ResetVector/SerialDebug.asm
@@ -0,0 +1,114 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2008, Intel Corporation
+; All rights reserved. This program and the accompanying materials
+; are licensed and made available under the terms and conditions of the BSD License
+; which accompanies this distribution.  The full text of the license may be found at
+; http://opensource.org/licenses/bsd-license.php
+;
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+;
+; Module Name:
+;
+;   SerialDebug.asm
+;
+; Abstract:
+;
+;   Serial port support macros
+;
+;------------------------------------------------------------------------------
+
+BITS    16
+
+;//---------------------------------------------
+;// UART Register Offsets
+;//---------------------------------------------
+%define BAUD_LOW_OFFSET         0x00
+%define BAUD_HIGH_OFFSET        0x01
+%define IER_OFFSET              0x01
+%define LCR_SHADOW_OFFSET       0x01
+%define FCR_SHADOW_OFFSET       0x02
+%define IR_CONTROL_OFFSET       0x02
+%define FCR_OFFSET              0x02
+%define EIR_OFFSET              0x02
+%define BSR_OFFSET              0x03
+%define LCR_OFFSET              0x03
+%define MCR_OFFSET              0x04
+%define LSR_OFFSET              0x05
+%define MSR_OFFSET              0x06
+
+;//---------------------------------------------
+;// UART Register Bit Defines
+;//---------------------------------------------
+%define LSR_TXRDY               0x20
+%define LSR_RXDA                0x01
+%define DLAB                    0x01
+
+; UINT16  gComBase = 0x3f8;
+; UINTN   gBps = 115200;
+; UINT8   gData = 8;
+; UINT8   gStop = 1;
+; UINT8   gParity = 0;
+; UINT8   gBreakSet = 0;
+
+%define DEFAULT_COM_BASE 0x3f8
+%define DEFAULT_BPS 115200
+%define DEFAULT_DATA 8
+%define DEFAULT_STOP 1
+%define DEFAULT_PARITY 0
+%define DEFAULT_BREAK_SET 0
+
+%define SERIAL_DEFAULT_LCR ( \
+     (DEFAULT_BREAK_SET << 6) | \
+     (DEFAULT_PARITY << 3) | \
+     (DEFAULT_STOP << 2) | \
+     (DEFAULT_DATA - 5) \
+    )
+
+%define SERIAL_PORT_IO_BASE_ADDRESS DEFAULT_COM_BASE
+
+%macro  inFromSerialPort 1
+    mov     dx, (SERIAL_PORT_IO_BASE_ADDRESS + %1)
+    in      al, dx
+%endmacro
+
+%macro  waitForSerialTxReady 0
+
+%%waitingForTx:
+    inFromSerialPort LSR_OFFSET
+    test    al, LSR_TXRDY
+    jz      %%waitingForTx
+
+%endmacro
+
+%macro  outToSerialPort 2
+    mov     dx, (SERIAL_PORT_IO_BASE_ADDRESS + %1)
+    mov     al, %2
+    out     dx, al
+%endmacro
+
+%macro  writeToSerialPort 1
+    waitForSerialTxReady
+    outToSerialPort 0, %1
+%endmacro
+
+real16InitSerialPort:
+    ;
+    ; Set communications format
+    ;
+    outToSerialPort LCR_OFFSET, ((DLAB << 7) | SERIAL_DEFAULT_LCR)
+
+    ;
+    ; Configure baud rate
+    ;
+    outToSerialPort BAUD_HIGH_OFFSET, ((115200 / DEFAULT_BPS) >> 8)
+    outToSerialPort BAUD_LOW_OFFSET, ((115200 / DEFAULT_BPS) & 0xff)
+
+    ;
+    ; Switch back to bank 0
+    ;
+    outToSerialPort LCR_OFFSET, SERIAL_DEFAULT_LCR
+
+    jmp     real16SerialPortInitReturn
+