drivers: console: add a minimal EFI console driver to support printf

Add a minimal EFI console driver to support printf, this console driver
only supports console output. Otherwise the printf will not work.

Signed-off-by: Enjia Mai <enjia.mai@intel.com>

arch/x86/Kconfig

@@ -489,6 +489,7 @@ config X86_EFI
 config X86_EFI_CONSOLE
 	bool
 	depends on X86_EFI && X86_64 && !X86_VERY_EARLY_CONSOLE
+	select EFI_CONSOLE
 	default y
 	help
 	  This enables the use of the UEFI console device as the

drivers/console/CMakeLists.txt

@@ -15,3 +15,4 @@ zephyr_library_sources_ifdef(CONFIG_UART_MCUMGR uart_mcumgr.c)
 zephyr_library_sources_ifdef(CONFIG_UART_MUX uart_mux.c)
 zephyr_library_sources_ifdef(CONFIG_UART_PIPE uart_pipe.c)
 zephyr_library_sources_ifdef(CONFIG_XTENSA_SIM_CONSOLE xtensa_sim_console.c)
+zephyr_library_sources_ifdef(CONFIG_EFI_CONSOLE efi_console.c)

drivers/console/Kconfig

@@ -384,5 +384,10 @@ config UART_MUX_VERBOSE_DEBUG
 	  As there might be lot of debug output printed, only enable
 	  this if really needed.
 
+config EFI_CONSOLE
+	bool "Use EFI console for console output"
+	select CONSOLE_HAS_DRIVER
+	help
+	  Enable this option to use EFI console output.
 
 endif # CONSOLE

drivers/console/efi_console.c

@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2022 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief EFI console driver
+ *
+ * @details EFI console driver.
+ * Hooks into the printk and fputc (for printf) modules.
+ */
+
+#include <stdio.h>
+#include <zephyr/device.h>
+#include <zephyr/init.h>
+#include <zephyr/sys/printk.h>
+
+
+extern int efi_console_putchar(int c);
+
+#if defined(CONFIG_PRINTK) || defined(CONFIG_STDOUT_CONSOLE)
+/**
+ *
+ * @brief Output one character to EFI console
+ *
+ * Outputs both line feed and carriage return in the case of a '\n'.
+ *
+ * @param c Character to output
+ *
+ * @return The character passed as input.
+ */
+
+static int console_out(int c)
+{
+	return efi_console_putchar(c);
+}
+
+#endif
+
+#if defined(CONFIG_STDOUT_CONSOLE)
+extern void __stdout_hook_install(int (*hook)(int));
+#endif
+
+#if defined(CONFIG_PRINTK)
+extern void __printk_hook_install(int (*fn)(int));
+#endif
+
+/**
+ * @brief Install printk/stdout hook for EFI console output
+ */
+
+static void efi_console_hook_install(void)
+{
+#if defined(CONFIG_STDOUT_CONSOLE)
+	__stdout_hook_install(console_out);
+#endif
+#if defined(CONFIG_PRINTK)
+	__printk_hook_install(console_out);
+#endif
+}
+
+/**
+ * @brief Initialize one EFI as the console port
+ *
+ * @return 0 if successful, otherwise failed.
+ */
+static int efi_console_init(const struct device *arg)
+{
+
+	ARG_UNUSED(arg);
+
+	efi_console_hook_install();
+
+	return 0;
+}
+
+/* EFI console initializes */
+SYS_INIT(efi_console_init,
+	PRE_KERNEL_1,
+	0);

kernel/Kconfig

@@ -324,7 +324,6 @@ config INIT_STACKS
 config BOOT_BANNER
 	bool "Boot banner"
 	default y
-	depends on CONSOLE_HAS_DRIVER
 	select PRINTK
 	select EARLY_CONSOLE
 	help