sandbox: Set up global data before board_init_f()

At present sandbox defines CONFIG_SYS_GENERIC_GLOBAL_DATA, meaning that
the global_data pointer is set up in board_init_f().

If we set up and zero the global data before calling board_init_f() then we
don't need to define CONFIG_SYS_GENERIC_GLOBAL_DATA.

Make this change to simplify the init process.
Signed-off-by: NSimon Glass <sjg@chromium.org>

arch/sandbox/cpu/start.c

@@ -6,6 +6,7 @@
 #include <common.h>
 #include <os.h>
 #include <asm/getopt.h>
+#include <asm/io.h>
 #include <asm/sections.h>
 #include <asm/state.h>
 
@@ -218,6 +219,7 @@ SANDBOX_CMDLINE_OPT_SHORT(terminal, 't', 1,
 int main(int argc, char *argv[])
 {
 	struct sandbox_state *state;
+	gd_t data;
 	int ret;
 
 	ret = state_init();
@@ -236,6 +238,9 @@ int main(int argc, char *argv[])
 	if (state->ram_buf_rm && state->ram_buf_fname)
 		os_unlink(state->ram_buf_fname);
 
+	memset(&data, '\0', sizeof(data));
+	gd = &data;
+
 	/* Do pre- and post-relocation init */
 	board_init_f(0);
 

arch/sandbox/include/asm/config.h

@@ -7,7 +7,6 @@
 #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 */