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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * File interface for UEFI variables
- *
- * Copyright (c) 2020, Heinrich Schuchardt
- */
- #include <common.h>
- #include <efi_loader.h>
- #include <efi_variable.h>
- #include <u-boot/crc.h>
- struct efi_var_file __efi_runtime_data *efi_var_buf;
- static struct efi_var_entry __efi_runtime_data *efi_current_var;
- /**
- * efi_var_mem_compare() - compare GUID and name with a variable
- *
- * @var: variable to compare
- * @guid: GUID to compare
- * @name: variable name to compare
- * @next: pointer to next variable
- * Return: true if match
- */
- static bool __efi_runtime
- efi_var_mem_compare(struct efi_var_entry *var, const efi_guid_t *guid,
- const u16 *name, struct efi_var_entry **next)
- {
- int i;
- u8 *guid1, *guid2;
- const u16 *data, *var_name;
- bool match = true;
- for (guid1 = (u8 *)&var->guid, guid2 = (u8 *)guid, i = 0;
- i < sizeof(efi_guid_t) && match; ++i)
- match = (guid1[i] == guid2[i]);
- for (data = var->name, var_name = name;; ++data, ++var_name) {
- if (match)
- match = (*data == *var_name);
- if (!*data)
- break;
- }
- ++data;
- if (next)
- *next = (struct efi_var_entry *)
- ALIGN((uintptr_t)data + var->length, 8);
- if (match)
- efi_current_var = var;
- return match;
- }
- struct efi_var_entry __efi_runtime
- *efi_var_mem_find(const efi_guid_t *guid, const u16 *name,
- struct efi_var_entry **next)
- {
- struct efi_var_entry *var, *last;
- last = (struct efi_var_entry *)
- ((uintptr_t)efi_var_buf + efi_var_buf->length);
- if (!*name) {
- if (next) {
- *next = efi_var_buf->var;
- if (*next >= last)
- *next = NULL;
- }
- return NULL;
- }
- if (efi_current_var &&
- efi_var_mem_compare(efi_current_var, guid, name, next)) {
- if (next && *next >= last)
- *next = NULL;
- return efi_current_var;
- }
- var = efi_var_buf->var;
- if (var < last) {
- for (; var;) {
- struct efi_var_entry *pos;
- bool match;
- match = efi_var_mem_compare(var, guid, name, &pos);
- if (pos >= last)
- pos = NULL;
- if (match) {
- if (next)
- *next = pos;
- return var;
- }
- var = pos;
- }
- }
- if (next)
- *next = NULL;
- return NULL;
- }
- void __efi_runtime efi_var_mem_del(struct efi_var_entry *var)
- {
- u16 *data;
- struct efi_var_entry *next, *last;
- if (!var)
- return;
- last = (struct efi_var_entry *)
- ((uintptr_t)efi_var_buf + efi_var_buf->length);
- if (var <= efi_current_var)
- efi_current_var = NULL;
- for (data = var->name; *data; ++data)
- ;
- ++data;
- next = (struct efi_var_entry *)
- ALIGN((uintptr_t)data + var->length, 8);
- efi_var_buf->length -= (uintptr_t)next - (uintptr_t)var;
- /* efi_memcpy_runtime() can be used because next >= var. */
- efi_memcpy_runtime(var, next, (uintptr_t)last - (uintptr_t)next);
- efi_var_buf->crc32 = crc32(0, (u8 *)efi_var_buf->var,
- efi_var_buf->length -
- sizeof(struct efi_var_file));
- }
- efi_status_t __efi_runtime efi_var_mem_ins(
- u16 *variable_name,
- const efi_guid_t *vendor, u32 attributes,
- const efi_uintn_t size1, const void *data1,
- const efi_uintn_t size2, const void *data2,
- const u64 time)
- {
- u16 *data;
- struct efi_var_entry *var;
- u32 var_name_len;
- var = (struct efi_var_entry *)
- ((uintptr_t)efi_var_buf + efi_var_buf->length);
- for (var_name_len = 0; variable_name[var_name_len]; ++var_name_len)
- ;
- ++var_name_len;
- data = var->name + var_name_len;
- if ((uintptr_t)data - (uintptr_t)efi_var_buf + size1 + size2 >
- EFI_VAR_BUF_SIZE)
- return EFI_OUT_OF_RESOURCES;
- var->attr = attributes;
- var->length = size1 + size2;
- var->time = time;
- efi_memcpy_runtime(&var->guid, vendor, sizeof(efi_guid_t));
- efi_memcpy_runtime(var->name, variable_name,
- sizeof(u16) * var_name_len);
- efi_memcpy_runtime(data, data1, size1);
- efi_memcpy_runtime((u8 *)data + size1, data2, size2);
- var = (struct efi_var_entry *)
- ALIGN((uintptr_t)data + var->length, 8);
- efi_var_buf->length = (uintptr_t)var - (uintptr_t)efi_var_buf;
- efi_var_buf->crc32 = crc32(0, (u8 *)efi_var_buf->var,
- efi_var_buf->length -
- sizeof(struct efi_var_file));
- return EFI_SUCCESS;
- }
- u64 __efi_runtime efi_var_mem_free(void)
- {
- return EFI_VAR_BUF_SIZE - efi_var_buf->length -
- sizeof(struct efi_var_entry);
- }
- /**
- * efi_var_mem_bs_del() - delete boot service only variables
- */
- static void efi_var_mem_bs_del(void)
- {
- struct efi_var_entry *var = efi_var_buf->var;
- for (;;) {
- struct efi_var_entry *last;
- last = (struct efi_var_entry *)
- ((uintptr_t)efi_var_buf + efi_var_buf->length);
- if (var >= last)
- break;
- if (var->attr & EFI_VARIABLE_RUNTIME_ACCESS) {
- u16 *data;
- /* skip variable */
- for (data = var->name; *data; ++data)
- ;
- ++data;
- var = (struct efi_var_entry *)
- ALIGN((uintptr_t)data + var->length, 8);
- } else {
- /* delete variable */
- efi_var_mem_del(var);
- }
- }
- }
- /**
- * efi_var_mem_notify_exit_boot_services() - ExitBootService callback
- *
- * @event: callback event
- * @context: callback context
- */
- static void EFIAPI
- efi_var_mem_notify_exit_boot_services(struct efi_event *event, void *context)
- {
- EFI_ENTRY("%p, %p", event, context);
- /* Delete boot service only variables */
- efi_var_mem_bs_del();
- EFI_EXIT(EFI_SUCCESS);
- }
- /**
- * efi_var_mem_notify_exit_boot_services() - SetVirtualMemoryMap callback
- *
- * @event: callback event
- * @context: callback context
- */
- static void EFIAPI __efi_runtime
- efi_var_mem_notify_virtual_address_map(struct efi_event *event, void *context)
- {
- efi_convert_pointer(0, (void **)&efi_var_buf);
- efi_current_var = NULL;
- }
- efi_status_t efi_var_mem_init(void)
- {
- u64 memory;
- efi_status_t ret;
- struct efi_event *event;
- ret = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES,
- EFI_RUNTIME_SERVICES_DATA,
- efi_size_in_pages(EFI_VAR_BUF_SIZE),
- &memory);
- if (ret != EFI_SUCCESS)
- return ret;
- efi_var_buf = (struct efi_var_file *)(uintptr_t)memory;
- memset(efi_var_buf, 0, EFI_VAR_BUF_SIZE);
- efi_var_buf->magic = EFI_VAR_FILE_MAGIC;
- efi_var_buf->length = (uintptr_t)efi_var_buf->var -
- (uintptr_t)efi_var_buf;
- /* crc32 for 0 bytes = 0 */
- ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
- efi_var_mem_notify_exit_boot_services, NULL,
- NULL, &event);
- if (ret != EFI_SUCCESS)
- return ret;
- ret = efi_create_event(EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE, TPL_CALLBACK,
- efi_var_mem_notify_virtual_address_map, NULL,
- NULL, &event);
- if (ret != EFI_SUCCESS)
- return ret;
- return ret;
- }
- efi_status_t __efi_runtime
- efi_get_variable_mem(u16 *variable_name, const efi_guid_t *vendor, u32 *attributes,
- efi_uintn_t *data_size, void *data, u64 *timep)
- {
- efi_uintn_t old_size;
- struct efi_var_entry *var;
- u16 *pdata;
- if (!variable_name || !vendor || !data_size)
- return EFI_INVALID_PARAMETER;
- var = efi_var_mem_find(vendor, variable_name, NULL);
- if (!var)
- return EFI_NOT_FOUND;
- if (attributes)
- *attributes = var->attr;
- if (timep)
- *timep = var->time;
- old_size = *data_size;
- *data_size = var->length;
- if (old_size < var->length)
- return EFI_BUFFER_TOO_SMALL;
- if (!data)
- return EFI_INVALID_PARAMETER;
- for (pdata = var->name; *pdata; ++pdata)
- ;
- ++pdata;
- efi_memcpy_runtime(data, pdata, var->length);
- return EFI_SUCCESS;
- }
- efi_status_t __efi_runtime
- efi_get_next_variable_name_mem(efi_uintn_t *variable_name_size,
- u16 *variable_name, efi_guid_t *vendor)
- {
- struct efi_var_entry *var;
- efi_uintn_t old_size;
- u16 *pdata;
- if (!variable_name_size || !variable_name || !vendor)
- return EFI_INVALID_PARAMETER;
- if (u16_strnlen(variable_name, *variable_name_size) ==
- *variable_name_size)
- return EFI_INVALID_PARAMETER;
- if (!efi_var_mem_find(vendor, variable_name, &var) && *variable_name)
- return EFI_INVALID_PARAMETER;
- if (!var)
- return EFI_NOT_FOUND;
- for (pdata = var->name; *pdata; ++pdata)
- ;
- ++pdata;
- old_size = *variable_name_size;
- *variable_name_size = (uintptr_t)pdata - (uintptr_t)var->name;
- if (old_size < *variable_name_size)
- return EFI_BUFFER_TOO_SMALL;
- efi_memcpy_runtime(variable_name, var->name, *variable_name_size);
- efi_memcpy_runtime(vendor, &var->guid, sizeof(efi_guid_t));
- return EFI_SUCCESS;
- }
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