x86: Introduce USE_EARLY_BOARD_INIT option

Introduce USE_EARLY_BOARD_INIT option and select it by the actual users.

Cc: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Aiden Park <aiden.park@intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/Kconfig

@@ -203,6 +203,9 @@ config SPL_X86_32BIT_INIT
 	help
 	  This is enabled when 32-bit init is in SPL
 
+config USE_EARLY_BOARD_INIT
+	bool
+
 config RESET_SEG_START
 	hex
 	depends on X86_RESET_VECTOR

arch/x86/cpu/start.S

@@ -88,6 +88,7 @@ _start:
 	/* Clear the interrupt vectors */
 	lidt	blank_idt_ptr
 
+#ifdef CONFIG_USE_EARLY_BOARD_INIT
 	/*
 	 * Critical early platform init - generally not used, we prefer init
 	 * to happen later when we have a console, in case something goes
@@ -96,6 +97,8 @@ _start:
 	jmp	early_board_init
 .globl early_board_init_ret
 early_board_init_ret:
+#endif
+
 	post_code(POST_START)
 
 	/* Initialise Cache-As-RAM */

board/google/chromebook_coral/Kconfig

@@ -18,6 +18,7 @@ config SYS_TEXT_BASE
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
 	select X86_RESET_VECTOR
+	select USE_EARLY_BOARD_INIT
 	select INTEL_APOLLOLAKE
 	select BOARD_ROMSIZE_KB_16384
 

board/google/chromebook_link/Kconfig

@@ -19,6 +19,7 @@ config SYS_TEXT_BASE
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
 	select X86_RESET_VECTOR
+	select USE_EARLY_BOARD_INIT
 	select NORTHBRIDGE_INTEL_IVYBRIDGE
 	select HAVE_INTEL_ME
 	select BOARD_ROMSIZE_KB_8192

board/google/chromebook_samus/Kconfig

@@ -19,6 +19,7 @@ config SYS_TEXT_BASE
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
 	select X86_RESET_VECTOR
+	select USE_EARLY_BOARD_INIT
 	select INTEL_BROADWELL
 	select HAVE_INTEL_ME
 	select BOARD_ROMSIZE_KB_8192