diff options
Diffstat (limited to 'src/cpu/x86/smm')
| -rw-r--r-- | src/cpu/x86/smm/Makefile.inc | 2 | ||||
| -rw-r--r-- | src/cpu/x86/smm/backup_default_smm.c | 68 |
2 files changed, 70 insertions, 0 deletions
diff --git a/src/cpu/x86/smm/Makefile.inc b/src/cpu/x86/smm/Makefile.inc index b595a36924..8dcd130117 100644 --- a/src/cpu/x86/smm/Makefile.inc +++ b/src/cpu/x86/smm/Makefile.inc @@ -17,6 +17,8 @@ ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA ## +ramstage-$(CONFIG_BACKUP_DEFAULT_SMM_REGION) += backup_default_smm.c + ifeq ($(CONFIG_SMM_MODULES),y) smmstub-y += smm_stub.S smmstub-y += smm_module_header.c diff --git a/src/cpu/x86/smm/backup_default_smm.c b/src/cpu/x86/smm/backup_default_smm.c new file mode 100644 index 0000000000..ef1d3a9e41 --- /dev/null +++ b/src/cpu/x86/smm/backup_default_smm.c @@ -0,0 +1,68 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2014 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 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * 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 <arch/acpi.h> +#include <console/console.h> +#include <cbmem.h> +#include <cpu/x86/smm.h> + +void *backup_default_smm_area(void) +{ + void *save_area; + const void *default_smm = (void *)SMM_DEFAULT_BASE; + + if (!IS_ENABLED(CONFIG_HAVE_ACPI_RESUME)) + return NULL; + + /* + * The buffer needs to be preallocated regardless. In the non-resume + * path it will be allocated for handling resume. Note that cbmem_add() + * does a find before the addition. + */ + save_area = cbmem_add(CBMEM_ID_SMM_SAVE_SPACE, SMM_DEFAULT_SIZE); + + if (save_area == NULL) { + printk(BIOS_DEBUG, "SMM save area not added.\n"); + return NULL; + } + + /* Only back up the area on S3 resume. */ + if (acpi_slp_type == 3) { + memcpy(save_area, default_smm, SMM_DEFAULT_SIZE); + return save_area; + } + + /* + * Not the S3 resume path. No need to restore memory contents after + * SMM relocation. + */ + return NULL; +} + +void restore_default_smm_area(void *smm_save_area) +{ + void *default_smm = (void *)SMM_DEFAULT_BASE; + + if (smm_save_area == NULL) + return; + + memcpy(default_smm, smm_save_area, SMM_DEFAULT_SIZE); +} |