Signed-off-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
---
lib/efi_loader/Kconfig | 14 +++
lib/efi_loader/efi_runtime.c | 4 +
lib/efi_loader/efi_variable.c | 108 ++++++++++++++++--
.../efi_selftest_variables_runtime.c | 13 ++-
4 files changed, 126 insertions(+), 13 deletions(-)
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index a7c3e05c13a0..c7f7383189e5 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -63,6 +63,20 @@ config EFI_VARIABLE_FILE_STORE
Select this option if you want non-volatile UEFI variables to be
stored as file /ubootefi.var on the EFI system partition.
+config EFI_RT_VOLATILE_STORE
+ bool "Allow variable runtime services in volatile storage (e.g RAM)"
+ depends on EFI_VARIABLE_FILE_STORE
+ help
+ When EFI variables are stored on file we don't allow SetVariableRT,
+ since the OS doesn't know how to write that file. At he same time
+ we copy runtime variables in DRAM and support GetVariableRT
+
+ Enable this option to allow SetVariableRT on the RAM backend of
+ the EFI variable storate. The OS will be responsible for syncing
+ the RAM contents to the file, otherwise any changes made during
+ runtime won't persist reboots.
+ Authenticated variables are not supported.
+
config EFI_MM_COMM_TEE
bool "UEFI variables storage service via the trusted world"
depends on OPTEE
diff --git a/lib/efi_loader/efi_runtime.c b/lib/efi_loader/efi_runtime.c
index 18da6892e796..b38ce239e2d2 100644
--- a/lib/efi_loader/efi_runtime.c
+++ b/lib/efi_loader/efi_runtime.c
@@ -126,6 +126,10 @@ efi_status_t efi_init_runtime_supported(void)
EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP |
EFI_RT_SUPPORTED_CONVERT_POINTER;
+ if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE))
+ rt_table->runtime_services_supported |=
+ EFI_RT_SUPPORTED_SET_VARIABLE;
+
/*
* This value must be synced with efi_runtime_detach_list
* as well as efi_runtime_services.
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 40f7a0fb10d5..3b770ff16971 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -218,17 +218,21 @@ efi_get_next_variable_name_int(efi_uintn_t
*variable_name_size,
return efi_get_next_variable_name_mem(variable_name_size,
variable_name, vendor);
}
-efi_status_t efi_set_variable_int(const u16 *variable_name,
- const efi_guid_t *vendor,
- u32 attributes, efi_uintn_t data_size,
- const void *data, bool ro_check)
+/**
+ * efi_check_setvariable() - checks defined by the UEFI spec for setvariable
+ *
+ * @variable_name: name of the variable
+ * @vendor: vendor GUID
+ * @attributes: attributes of the variable
+ * @data_size: size of the buffer with the variable value
+ * @data: buffer with the variable value
+ * Return: status code
+ */
+static efi_status_t __efi_runtime EFIAPI
+efi_check_setvariable(const u16 *variable_name, const efi_guid_t *vendor,
+ u32 attributes, efi_uintn_t data_size,
+ const void *data)
{
- struct efi_var_entry *var;
- efi_uintn_t ret;
- bool append, delete;
- u64 time = 0;
- enum efi_auth_var_type var_type;
-
if (!variable_name || !*variable_name || !vendor)
return EFI_INVALID_PARAMETER;
@@ -256,6 +260,25 @@ efi_status_t efi_set_variable_int(const u16 *variable_name,
!(attributes & EFI_VARIABLE_BOOTSERVICE_ACCESS)))
return EFI_INVALID_PARAMETER;
+ return EFI_SUCCESS;
+}
+
+efi_status_t efi_set_variable_int(const u16 *variable_name,
+ const efi_guid_t *vendor,
+ u32 attributes, efi_uintn_t data_size,
+ const void *data, bool ro_check)
+{
+ struct efi_var_entry *var;
+ efi_uintn_t ret;
+ bool append, delete;
+ u64 time = 0;
+ enum efi_auth_var_type var_type;
+
+ ret = efi_check_setvariable(variable_name, vendor, attributes,
data_size,
+ data);
+ if (ret != EFI_SUCCESS)
+ return ret;
+
/* check if a variable exists */
var = efi_var_mem_find(vendor, variable_name, NULL);
append = !!(attributes & EFI_VARIABLE_APPEND_WRITE);
@@ -434,7 +457,72 @@ efi_set_variable_runtime(u16 *variable_name, const
efi_guid_t *vendor,
u32 attributes, efi_uintn_t data_size,
const void *data)
{
+#if IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)
+ struct efi_var_entry *var;
+ efi_uintn_t ret;
+ bool append, delete;
+ u64 time = 0;
+
+ /* Authenticated variables are not supported */
+ if (attributes & EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS)
+ return EFI_INVALID_PARAMETER;
+
+ ret = efi_check_setvariable(variable_name, vendor, attributes,
data_size,
+ data);
+ if (ret != EFI_SUCCESS)
+ return ret;
+
+ /* check if a variable exists */
+ var = efi_var_mem_find(vendor, variable_name, NULL);
+ append = !!(attributes & EFI_VARIABLE_APPEND_WRITE);
+ attributes &= ~(u32)EFI_VARIABLE_APPEND_WRITE;
+ delete = !append && (!data_size || !attributes);
+
+ if (var) {
+ if (var->attr & EFI_VARIABLE_READ_ONLY)
+ return EFI_WRITE_PROTECTED;
+
+ /* attributes won't be changed */
+ if (!delete && (((var->attr & ~(u32)EFI_VARIABLE_READ_ONLY) !=
+ (attributes & ~(u32)EFI_VARIABLE_READ_ONLY))))
+ return EFI_INVALID_PARAMETER;
+ time = var->time;
+ } else {
+ if (delete || append)
+ /*
+ * Trying to delete or to update a non-existent
+ * variable.
+ */
+ return EFI_NOT_FOUND;
+ }
+
+ if (delete) {
+ /* EFI_NOT_FOUND has been handled before */
+ attributes = var->attr;
+ ret = EFI_SUCCESS;
+ } else if (append) {
+ u16 *old_data = var->name;
+
+ for (; *old_data; ++old_data)
+ ;
+ ++old_data;
+ ret = efi_var_mem_ins(variable_name, vendor, attributes,
+ var->length, old_data, data_size, data,
+ time);
+ } else {
+ ret = efi_var_mem_ins(variable_name, vendor, attributes,
+ data_size, data, 0, NULL, time);
+ }
+
+ if (ret != EFI_SUCCESS)
+ return ret;
+ /* We are always inserting new variables, get rid of the old copy */
+ efi_var_mem_del(var);
+
+ return EFI_SUCCESS;
+#else
return EFI_UNSUPPORTED;
+#endif
}
/**
diff --git a/lib/efi_selftest/efi_selftest_variables_runtime.c
b/lib/efi_selftest/efi_selftest_variables_runtime.c
index 4700d9424105..6001b44989c8 100644
--- a/lib/efi_selftest/efi_selftest_variables_runtime.c
+++ b/lib/efi_selftest/efi_selftest_variables_runtime.c
@@ -62,9 +62,16 @@ static int execute(void)
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS,
3, v + 4);
- if (ret != EFI_UNSUPPORTED) {
- efi_st_error("SetVariable failed\n");
- return EFI_ST_FAILURE;
+ if (IS_ENABLED(CONFIG_EFI_RT_VOLATILE_STORE)) {
+ if (ret != EFI_SUCCESS) {
+ efi_st_error("SetVariable failed\n");
+ return EFI_ST_FAILURE;
+ }
+ } else {
+ if (ret != EFI_UNSUPPORTED) {
+ efi_st_error("SetVariable failed\n");
+ return EFI_ST_FAILURE;
+ }
}
len = EFI_ST_MAX_DATA_SIZE;
ret = runtime->get_variable(u"PlatformLangCodes", &guid_vendor0,
--
2.37.2
