common/board_f: Initialized global data for generic board

Some platforms (tested on mpc85xx, mpc86xx) use global data before calling
function baord_inti_f(). The data should not be cleared later. Any arch
which uses global data in generic board board_init_f() should define
CONFIG_SYS_GENERIC_GLOBAL_DATA.

Signed-off-by: York Sun <yorksun@freescale.com>
CC: Scott Wood <scottwood@freescale.com>
CC: Simon Glass <sjg@chromium.org>
CC: Albert ARIBAUD <albert.u.boot@aribaud.net>
Acked-by: Simon Glass <sjg@chromium.org>

README

@@ -451,6 +451,12 @@ The following options need to be configured:
 		supported, core will start to execute uboot when wakes up.
 
 - Generic CPU options:
+		CONFIG_SYS_GENERIC_GLOBAL_DATA
+		Defines global data is initialized in generic board board_init_f().
+		If this macro is defined, global data is created and cleared in
+		generic board board_init_f(). Without this macro, architecture/board
+		should initialize global data before calling board_init_f().
+
 		CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
 
 		Defines the endianess of the CPU. Implementation of those

arch/arc/include/asm/config.h

@@ -7,6 +7,8 @@
 #ifndef __ASM_ARC_CONFIG_H_
 #define __ASM_ARC_CONFIG_H_
 
+#define CONFIG_SYS_GENERIC_GLOBAL_DATA
+
 #define CONFIG_LMB
 
 #endif /*__ASM_ARC_CONFIG_H_ */

arch/arm/include/asm/config.h

@@ -7,6 +7,8 @@
 #ifndef _ASM_CONFIG_H_
 #define _ASM_CONFIG_H_
 
+#define CONFIG_SYS_GENERIC_GLOBAL_DATA
+
 #define CONFIG_LMB
 #define CONFIG_SYS_BOOT_RAMDISK_HIGH
 

arch/mips/include/asm/config.h

@@ -7,6 +7,8 @@
 #ifndef _ASM_CONFIG_H_
 #define _ASM_CONFIG_H_
 
+#define CONFIG_SYS_GENERIC_GLOBAL_DATA
+
 #define CONFIG_LMB
 #define CONFIG_SYS_BOOT_RAMDISK_HIGH
 

arch/sandbox/include/asm/config.h

@@ -7,6 +7,7 @@
 #ifndef _ASM_CONFIG_H_
 #define _ASM_CONFIG_H_
 
+#define CONFIG_SYS_GENERIC_GLOBAL_DATA
 #define CONFIG_SANDBOX_ARCH
 
 /* Used by drivers/spi/sandbox_spi.c and arch/sandbox/include/asm/state.h */

common/board_f.c

@@ -961,20 +961,22 @@ static init_fnc_t init_sequence_f[] = {
 
 void board_init_f(ulong boot_flags)
 {
-#ifndef CONFIG_X86
+#ifdef CONFIG_SYS_GENERIC_GLOBAL_DATA
+	/*
+	 * For some archtectures, global data is initialized and used before
+	 * calling this function. The data should be preserved. For others,
+	 * CONFIG_SYS_GENERIC_GLOBAL_DATA should be defined and use the stack
+	 * here to host global data until relocation.
+	 */
 	gd_t data;
 
 	gd = &data;
-#endif
 
 	/*
 	 * Clear global data before it is accessed at debug print
 	 * in initcall_run_list. Otherwise the debug print probably
 	 * get the wrong vaule of gd->have_console.
 	 */
-#if !defined(CONFIG_CPM2) && !defined(CONFIG_MPC512X) && \
-		!defined(CONFIG_MPC83xx) && !defined(CONFIG_MPC85xx) && \
-		!defined(CONFIG_MPC86xx) && !defined(CONFIG_X86)
 	zero_global_data();
 #endif