From 9d7491c73211997681df0eed9607a0fd1528133d Mon Sep 17 00:00:00 2001
From: belliash <belliash@codingworkshop.eu.org>
Date: Wed, 3 Aug 2022 22:36:31 +0200
Subject: [PATCH] EFI default console support

---
 xtldr/CMakeLists.txt  |  1 +
 xtldr/console.c       | 75 +++++++++++++++++++++++++++++++++++++++++++
 xtldr/includes/xtbl.h |  9 ++++++
 xtldr/xtldr.c         | 10 ++++++
 4 files changed, 95 insertions(+)
 create mode 100644 xtldr/console.c

diff --git a/xtldr/CMakeLists.txt b/xtldr/CMakeLists.txt
index 5aa7134..525ff1e 100644
--- a/xtldr/CMakeLists.txt
+++ b/xtldr/CMakeLists.txt
@@ -8,6 +8,7 @@ include_directories(
 
 # Specify list of source code files
 list(APPEND XTLDR_SOURCE
+    ${XTLDR_SOURCE_DIR}/console.c
     ${XTLDR_SOURCE_DIR}/xtldr.c)
 
 # Add executable
diff --git a/xtldr/console.c b/xtldr/console.c
new file mode 100644
index 0000000..7d7f9cc
--- /dev/null
+++ b/xtldr/console.c
@@ -0,0 +1,75 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtldr/console.c
+ * DESCRIPTION:     EFI console support
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#include <xtbl.h>
+
+
+/**
+ * This routine clears the UEFI console screen.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+VOID
+BlConsoleClearScreen()
+{
+    EfiSystemTable->ConOut->ClearScreen(EfiSystemTable->ConOut);
+}
+
+/**
+ * This routine initializes the EFI console.
+ * 
+ * @return This routine returns status code.
+ * 
+ * @since XT 1.0
+ */
+EFI_STATUS
+BlConsoleInitialize()
+{
+    /* Check the console support */
+    if(!EfiSystemTable->ConOut)
+    {
+        return STATUS_EFI_UNSUPPORTED;
+    }
+
+    /* Clear console buffers */
+    EfiSystemTable->ConIn->Reset(EfiSystemTable->ConIn, TRUE);
+    EfiSystemTable->ConOut->Reset(EfiSystemTable->ConOut, TRUE);
+    EfiSystemTable->StdErr->Reset(EfiSystemTable->StdErr, TRUE);
+
+    /* Clear screen */
+    BlConsoleClearScreen();
+
+    /* Enable cursor */
+    EfiSystemTable->ConOut->EnableCursor(EfiSystemTable->ConOut, TRUE);
+
+    /* Return success */
+    return STATUS_EFI_SUCCESS;
+}
+
+/**
+ * Writes a character to the default EFI console.
+ *
+ * @param Character
+ *        The integer promotion of the character to be written.
+ *
+ * @return This routine does not return any value.
+ *
+ * @since XT 1.0
+ */
+VOID
+BlConsolePutChar(IN USHORT Character)
+{
+    USHORT Buffer[2];
+
+    /* Write character to the screen console */
+    Buffer[0] = Character;
+    Buffer[1] = 0;
+    EfiSystemTable->ConOut->OutputString(EfiSystemTable->ConOut, Buffer);
+}
diff --git a/xtldr/includes/xtbl.h b/xtldr/includes/xtbl.h
index d4fc6d2..32f5faa 100644
--- a/xtldr/includes/xtbl.h
+++ b/xtldr/includes/xtbl.h
@@ -18,6 +18,15 @@ EXTERN EFI_HANDLE EfiImageHandle;
 /* EFI System Table */
 EXTERN EFI_SYSTEM_TABLE *EfiSystemTable;
 
+VOID
+BlConsoleClearScreen();
+
+EFI_STATUS
+BlConsoleInitialize();
+
+VOID
+BlConsolePutChar(IN USHORT Character);
+
 EFI_STATUS
 XtLoaderStartup(IN EFI_HANDLE ImageHandle,
                 IN PEFI_SYSTEM_TABLE SystemTable);
diff --git a/xtldr/xtldr.c b/xtldr/xtldr.c
index 9e2638f..53c4d8c 100644
--- a/xtldr/xtldr.c
+++ b/xtldr/xtldr.c
@@ -32,10 +32,20 @@ EFI_STATUS
 XtLoaderStartup(IN EFI_HANDLE ImageHandle,
                 IN PEFI_SYSTEM_TABLE SystemTable)
 {
+    EFI_STATUS Status;
+
     /* Set the system table and image handle */
     EfiImageHandle = ImageHandle;
     EfiSystemTable = SystemTable;
 
+    /* Initialize EFI console */
+    Status = BlConsoleInitialize();
+    if(Status != STATUS_EFI_SUCCESS) {
+        /* TODO: Display error message on the serial console */
+        /* Temporarily return error code */
+        return STATUS_EFI_INCOMPATIBLE_VERSION;
+    }
+
     /* Infinite bootloader loop */
     for(;;);