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Diffstat (limited to 'lib/efi_loader/efi_var_common.c')
| -rw-r--r-- | lib/efi_loader/efi_var_common.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/lib/efi_loader/efi_var_common.c b/lib/efi_loader/efi_var_common.c new file mode 100644 index 0000000000..1e2be1135b --- /dev/null +++ b/lib/efi_loader/efi_var_common.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * UEFI runtime variable services + * + * Copyright (c) 2020, Heinrich Schuchardt <xypron.glpk@gmx.de> + */ + +#include <common.h> +#include <efi_loader.h> +#include <efi_variable.h> + +/** + * efi_efi_get_variable() - retrieve value of a UEFI variable + * + * This function implements the GetVariable runtime service. + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * @variable_name: name of the variable + * @vendor: vendor GUID + * @attributes: attributes of the variable + * @data_size: size of the buffer to which the variable value is copied + * @data: buffer to which the variable value is copied + * Return: status code + */ +efi_status_t EFIAPI efi_get_variable(u16 *variable_name, + const efi_guid_t *vendor, u32 *attributes, + efi_uintn_t *data_size, void *data) +{ + efi_status_t ret; + + EFI_ENTRY("\"%ls\" %pUl %p %p %p", variable_name, vendor, attributes, + data_size, data); + + ret = efi_get_variable_int(variable_name, vendor, attributes, + data_size, data, NULL); + + /* Remove EFI_VARIABLE_READ_ONLY flag */ + if (attributes) + *attributes &= EFI_VARIABLE_MASK; + + return EFI_EXIT(ret); +} + +/** + * efi_set_variable() - set value of a UEFI variable + * + * This function implements the SetVariable runtime service. + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * @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 + */ +efi_status_t EFIAPI efi_set_variable(u16 *variable_name, + const efi_guid_t *vendor, u32 attributes, + efi_uintn_t data_size, const void *data) +{ + efi_status_t ret; + + EFI_ENTRY("\"%ls\" %pUl %x %zu %p", variable_name, vendor, attributes, + data_size, data); + + /* Make sure that the EFI_VARIABLE_READ_ONLY flag is not set */ + if (attributes & ~(u32)EFI_VARIABLE_MASK) + ret = EFI_INVALID_PARAMETER; + else + ret = efi_set_variable_int(variable_name, vendor, attributes, + data_size, data, true); + + return EFI_EXIT(ret); +} + +/** + * efi_get_next_variable_name() - enumerate the current variable names + * + * @variable_name_size: size of variable_name buffer in byte + * @variable_name: name of uefi variable's name in u16 + * @vendor: vendor's guid + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * Return: status code + */ +efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size, + u16 *variable_name, + efi_guid_t *vendor) +{ + efi_status_t ret; + + EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, vendor); + + ret = efi_get_next_variable_name_int(variable_name_size, variable_name, + vendor); + + return EFI_EXIT(ret); +} + +/** + * efi_query_variable_info() - get information about EFI variables + * + * This function implements the QueryVariableInfo() runtime service. + * + * See the Unified Extensible Firmware Interface (UEFI) specification for + * details. + * + * @attributes: bitmask to select variables to be + * queried + * @maximum_variable_storage_size: maximum size of storage area for the + * selected variable types + * @remaining_variable_storage_size: remaining size of storage are for the + * selected variable types + * @maximum_variable_size: maximum size of a variable of the + * selected type + * Returns: status code + */ +efi_status_t EFIAPI efi_query_variable_info( + u32 attributes, u64 *maximum_variable_storage_size, + u64 *remaining_variable_storage_size, + u64 *maximum_variable_size) +{ + efi_status_t ret; + + EFI_ENTRY("%x %p %p %p", attributes, maximum_variable_storage_size, + remaining_variable_storage_size, maximum_variable_size); + + ret = efi_query_variable_info_int(attributes, + maximum_variable_storage_size, + remaining_variable_storage_size, + maximum_variable_size); + + return EFI_EXIT(ret); +} |