Enable CAR_MIGRATION on Exynos 5250 and 5420

... and move the Kconfig variable from cpu/x86/Kconfig to cpu/Kconfig
Despite calling romstage memory CAR in this case, the variables actually
do live in SRAM on the Exynos CPUs. However, in order to share as much
generic code as possible, we're using the same infrastructure here.

BRANCH=none
BUG=chrome-os-partner:18637
TEST=none

Change-Id: I85173c37099a25f3e55980e88120401826cdf29c
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/62188
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: Stefan Reinauer <reinauer@chromium.org>
Tested-by: Stefan Reinauer <reinauer@chromium.org>

src/arch/armv7/romstage.ld

@@ -47,10 +47,28 @@ SECTIONS
 		*(.rodata);
 		*(.machine_param);
 		*(.data);
-		. = ALIGN(8);
+		. = ALIGN(16);
+		_car_migrate_start = .;
+		*(.car.migrate);
+		_car_migrate_end = .;
+		. = ALIGN(16);
 		_erom = .;
 	}
 
+	.car.data . (NOLOAD) : {
+		_car_data_start = .;
+		*(.car.global_data);
+		/* The cbmem_console section comes last to take advantage of
+		 * a zero-sized array to hold the memconsole contents that
+		 * grows to a bound of CONFIG_CONSOLE_CAR_BUFFER_SIZE. However,
+		 * collisions within the cache-as-ram region cannot be
+		 * statically checked because the cache-as-ram region usage is
+		 * cpu/chipset dependent. */
+		*(.car.cbmem_console);
+		_car_data_end = .;
+	}
+
+
 	__image_copy_end = .;
 
 	/* bss does not contain data, it is just a space that should be zero

src/cpu/Kconfig

@@ -150,6 +150,14 @@ config CPU_MICROCODE_CBFS_NONE
 
 endchoice
 
+config CAR_MIGRATION
+	def_bool n
+	depends on DYNAMIC_CBMEM || EARLY_CBMEM_INIT
+	help
+	  Migrate the cache-as-ram variables to CBMEM once CBMEM is set up
+	  in romstage. This option is only needed if one will be doing more
+	  work in romstage after the cache-as-ram is torn down aside from
+	  loading ramstage.
 config CPU_MICROCODE_FILE
 	  string "Path and filename of CPU microcode"
 	  depends on CPU_MICROCODE_CBFS_EXTERNAL

src/cpu/samsung/exynos5250/Kconfig

@@ -4,6 +4,7 @@ config CPU_SAMSUNG_EXYNOS5250
 	select HAVE_UART_SPECIAL
 	select EARLY_CONSOLE
 	select DYNAMIC_CBMEM
+	select CAR_MIGRATION
 	bool
 	default n
 

src/cpu/samsung/exynos5420/Kconfig

@@ -4,6 +4,7 @@ config CPU_SAMSUNG_EXYNOS5420
 	select HAVE_UART_SPECIAL
 	select EARLY_CONSOLE
 	select DYNAMIC_CBMEM
+	select CAR_MIGRATION
 	bool
 	default n
 

src/cpu/x86/Kconfig

@@ -116,11 +116,4 @@ config X86_AMD_FIXED_MTRRS
 	  This option informs the MTRR code to use the RdMem and WrMem fields
 	  in the fixed MTRR MSRs.
 
-config CAR_MIGRATION
-	def_bool n
-	depends on DYNAMIC_CBMEM || EARLY_CBMEM_INIT
-	help
-	  Migrate the cache-as-ram variables to CBMEM once CBMEM is set up
-	  in romstage. This option is only needed if one will be doing more
-	  work in romstage after the cache-as-ram is torn down aside from
-	  loading ramstage.
+