From 716738a6b84535f731ee9749f161505945eab93c Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Fri, 10 May 2013 00:33:32 -0500 Subject: x86: add cache-as-ram migration option There are some boards that do a significant amount of work after cache-as-ram is torn down but before ramstage is loaded. For example, using vboot to verify the ramstage is one such operation. However, there are pieces of code that are executed that reference global variables that are linked in the cache-as-ram region. If those variables are referenced after cache-as-ram is torn down then the values observed will most likely be incorrect. Therefore provide a Kconfig option to select cache-as-ram migration to memory using cbmem. This option is named CAR_MIGRATION. When enabled, the address of cache-as-ram variables may be obtained dynamically. Additionally, when cache-as-ram migration occurs the cache-as-ram data region for global variables is copied into cbmem. There are also automatic callbacks for other modules to perform their own migration, if necessary. Change-Id: I2e77219647c2bd2b1aa845b262be3b2543f1fcb7 Signed-off-by: Aaron Durbin Reviewed-on: http://review.coreboot.org/3232 Reviewed-by: Paul Menzel Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- src/include/cbmem.h | 1 + src/include/cpu/x86/car.h | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) (limited to 'src/include') diff --git a/src/include/cbmem.h b/src/include/cbmem.h index 67cb1cb7e5..baec780156 100644 --- a/src/include/cbmem.h +++ b/src/include/cbmem.h @@ -69,6 +69,7 @@ #define CBMEM_ID_RAMSTAGE_CACHE 0x9a3ca54e #define CBMEM_ID_ROOT 0xff4007ff #define CBMEM_ID_VBOOT_HANDOFF 0x780074f0 +#define CBMEM_ID_CAR_GLOBALS 0xcac4e6a3 #define CBMEM_ID_NONE 0x00000000 #ifndef __ASSEMBLER__ diff --git a/src/include/cpu/x86/car.h b/src/include/cpu/x86/car.h index 2d2af03a37..7b5cedf213 100644 --- a/src/include/cpu/x86/car.h +++ b/src/include/cpu/x86/car.h @@ -28,4 +28,33 @@ #define CAR_CBMEM #endif +#if CONFIG_CAR_MIGRATION && defined(__PRE_RAM__) +#define CAR_MIGRATE_ATTR __attribute__ ((used,section (".car.migrate"))) + +/* Call migrate_fn_() when CAR globals are migrated. */ +#define CAR_MIGRATE(migrate_fn_) \ + static void (* const migrate_fn_ ## _ptr)(void) CAR_MIGRATE_ATTR = \ + migrate_fn_; + +/* Get the correct pointer for the CAR global variable. */ +void *car_get_var_ptr(void *var); + +/* Get and set a primitive type global variable. */ +#define car_get_var(var) \ + *(typeof(var) *)car_get_var_ptr(&(var)) +#define car_set_var(var, val) \ + do { car_get_var(var) = (val); } while(0) + +/* Migrate the CAR variables to memory. */ +void car_migrate_variables(void); + +#else +#define CAR_MIGRATE(migrate_fn_) +static inline void *car_get_var_ptr(void *var) { return var; } +#define car_get_var(var) (var) +#define car_set_var(var, val) do { (var) = (val); } while (0) +static inline void car_migrate_variables(void) { } +#endif + + #endif -- cgit v1.2.3