blob: 23282cd89cd73b669535bc2955681b558ac0641c [file] [log] [blame]
* This file is part of the coreboot project.
* Copyright (C) 2013 Google, Inc.
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#include <string.h>
#include <stddef.h>
#include <console/console.h>
#include <cbmem.h>
#include <arch/early_variables.h>
typedef void (* const car_migration_func_t)(void);
extern car_migration_func_t _car_migrate_start;
extern car_migration_func_t _car_migrate_end;
extern char _car_data_start[];
extern char _car_data_end[];
* The car_migrated global variable determines if the cache-as-ram space has
* been migrated to real RAM. It does this by asumming the following things:
* 1. cache-as-ram space is zero'd out once it is set up.
* 2. Either the cache-as-ram space is memory-backed after getting torn down
* or the space returns 0xff's for each byte read.
* Based on these 2 attributes there is the ability to tell when the
* cache-as-ram region has been migrated.
static int car_migrated CAR_GLOBAL;
void *car_get_var_ptr(void *var)
char *migrated_base;
int offset;
void * _car_start = &_car_data_start;
void * _car_end = &_car_data_end;
/* If the cache-as-ram has not been migrated return the pointer
* passed in. */
if (!car_migrated)
return var;
if (var < _car_start || var >= _car_end) {
"Requesting CAR variable outside of CAR region: %p\n",
return var;
migrated_base = cbmem_find(CBMEM_ID_CAR_GLOBALS);
if (migrated_base == NULL) {
printk(BIOS_ERR, "CAR: Could not find migration base!\n");
return var;
offset = (char *)var - (char *)_car_start;
return &migrated_base[offset];
void car_migrate_variables(void)
void *migrated_base;
car_migration_func_t *migrate_func;
size_t car_data_size = &_car_data_end[0] - &_car_data_start[0];
migrated_base = cbmem_add(CBMEM_ID_CAR_GLOBALS, car_data_size);
if (migrated_base == NULL) {
printk(BIOS_ERR, "Could not migrate CAR data!\n");
memcpy(migrated_base, &_car_data_start[0], car_data_size);
/* Mark that the data has been moved. */
car_migrated = ~0;
/* Call all the migration functions. */
migrate_func = &_car_migrate_start;
while (migrate_func != &_car_migrate_end) {