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Diffstat (limited to 'include_all/hardware/nvram.h')
| -rw-r--r-- | include_all/hardware/nvram.h | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/include_all/hardware/nvram.h b/include_all/hardware/nvram.h new file mode 100644 index 00000000..0654afef --- /dev/null +++ b/include_all/hardware/nvram.h @@ -0,0 +1,338 @@ +/* + * Copyright (C) 2015 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef ANDROID_HARDWARE_NVRAM_H +#define ANDROID_HARDWARE_NVRAM_H + +#include <stdint.h> +#include <sys/cdefs.h> + +#include <hardware/hardware.h> +#include <hardware/nvram_defs.h> + +__BEGIN_DECLS + +/* The id of this module. */ +#define NVRAM_HARDWARE_MODULE_ID "nvram" +#define NVRAM_HARDWARE_DEVICE_ID "nvram-dev" + +/* The version of this module. */ +#define NVRAM_MODULE_API_VERSION_0_1 HARDWARE_MODULE_API_VERSION(0, 1) +#define NVRAM_DEVICE_API_VERSION_1_1 HARDWARE_DEVICE_API_VERSION(1, 1) + +struct nvram_module { + /** + * Common methods of the nvram_module. This *must* be the first member of + * nvram_module as users of this structure will cast a hw_module_t to + * nvram_module pointer in contexts where it's known the hw_module_t + * references a nvram_module. + */ + hw_module_t common; + + /* There are no module methods other than the common ones. */ +}; + +struct nvram_device { + /** + * Common methods of the nvram_device. This *must* be the first member of + * nvram_device as users of this structure will cast a hw_device_t to + * nvram_device pointer in contexts where it's known the hw_device_t + * references a nvram_device. + */ + struct hw_device_t common; + + /** + * Outputs the total number of bytes available in NVRAM. This will + * always be at least 2048. If an implementation does not know the + * total size it may provide an estimate or 2048. + * + * device - The nvram_device instance. + * total_size - Receives the output. Cannot be NULL. + */ + nvram_result_t (*get_total_size_in_bytes)(const struct nvram_device* device, + uint64_t* total_size); + + /** + * Outputs the unallocated number of bytes available in NVRAM. If an + * implementation does not know the available size it may provide an + * estimate or the total size. + * + * device - The nvram_device instance. + * available_size - Receives the output. Cannot be NULL. + */ + nvram_result_t (*get_available_size_in_bytes)( + const struct nvram_device* device, uint64_t* available_size); + + /** + * Outputs the maximum number of bytes that can be allocated for a single + * space. This will always be at least 32. If an implementation does not + * limit the maximum size it may provide the total size. + * + * device - The nvram_device instance. + * max_space_size - Receives the output. Cannot be NULL. + */ + nvram_result_t (*get_max_space_size_in_bytes)( + const struct nvram_device* device, uint64_t* max_space_size); + + /** + * Outputs the maximum total number of spaces that may be allocated. + * This will always be at least 8. Outputs NV_UNLIMITED_SPACES if any + * number of spaces are supported (limited only to available NVRAM + * bytes). + * + * device - The nvram_device instance. + * num_spaces - Receives the output. Cannot be NULL. + */ + nvram_result_t (*get_max_spaces)(const struct nvram_device* device, + uint32_t* num_spaces); + + /** + * Outputs a list of created space indices. If |max_list_size| is + * 0, only |list_size| is populated. + * + * device - The nvram_device instance. + * max_list_size - The number of items in the |space_index_list| + * array. + * space_index_list - Receives the list of created spaces up to the + * given |max_list_size|. May be NULL if + * |max_list_size| is 0. + * list_size - Receives the number of items populated in + * |space_index_list|, or the number of items available + * if |space_index_list| is NULL. + */ + nvram_result_t (*get_space_list)(const struct nvram_device* device, + uint32_t max_list_size, + uint32_t* space_index_list, + uint32_t* list_size); + + /** + * Outputs the size, in bytes, of a given space. + * + * device - The nvram_device instance. + * index - The space index. + * size - Receives the output. Cannot be NULL. + */ + nvram_result_t (*get_space_size)(const struct nvram_device* device, + uint32_t index, uint64_t* size); + + /** + * Outputs the list of controls associated with a given space. + * + * device - The nvram_device instance. + * index - The space index. + * max_list_size - The number of items in the |control_list| array. + * control_list - Receives the list of controls up to the given + * |max_list_size|. May be NULL if |max_list_size| + * is 0. + * list_size - Receives the number of items populated in + * |control_list|, or the number of items available if + * |control_list| is NULL. + */ + nvram_result_t (*get_space_controls)(const struct nvram_device* device, + uint32_t index, uint32_t max_list_size, + nvram_control_t* control_list, + uint32_t* list_size); + + /** + * Outputs whether locks are enabled for the given space. When a lock + * is enabled, the operation is disabled and any attempt to perform that + * operation will result in NV_RESULT_OPERATION_DISABLED. + * + * device - The nvram_device instance. + * index - The space index. + * write_lock_enabled - Will be set to non-zero iff write + * operations are currently disabled. + * read_lock_enabled - Will be set to non-zero iff read operations + * are currently disabled. + */ + nvram_result_t (*is_space_locked)(const struct nvram_device* device, + uint32_t index, int* write_lock_enabled, + int* read_lock_enabled); + + /** + * Creates a new space with the given index, size, controls, and + * authorization value. + * + * device - The nvram_device instance. + * index - An index for the new space. The index can be any 32-bit + * value but must not already be assigned to an existing + * space. + * size_in_bytes - The number of bytes to allocate for the space. + * control_list - An array of controls to enforce for the space. + * list_size - The number of items in |control_list|. + * authorization_value - If |control_list| contains + * NV_CONTROL_READ_AUTHORIZATION and / or + * NV_CONTROL_WRITE_AUTHORIZATION, then this + * parameter provides the authorization value + * for these policies (if both controls are + * set then this value applies to both). + * Otherwise, this value is ignored and may + * be NULL. + * authorization_value_size - The number of bytes in + * |authorization_value|. + */ + nvram_result_t (*create_space)(const struct nvram_device* device, + uint32_t index, uint64_t size_in_bytes, + const nvram_control_t* control_list, + uint32_t list_size, + const uint8_t* authorization_value, + uint32_t authorization_value_size); + + /** + * Deletes a space. + * + * device - The nvram_device instance. + * index - The space index. + * authorization_value - If the space has the + * NV_CONTROL_WRITE_AUTHORIZATION policy, + * then this parameter provides the + * authorization value. Otherwise, this value + * is ignored and may be NULL. + * authorization_value_size - The number of bytes in + * |authorization_value|. + */ + nvram_result_t (*delete_space)(const struct nvram_device* device, + uint32_t index, + const uint8_t* authorization_value, + uint32_t authorization_value_size); + + /** + * Disables any further creation of spaces until the next full device + * reset (as in factory reset, not reboot). Subsequent calls to + * NV_CreateSpace should return NV_RESULT_OPERATION_DISABLED. + * + * device - The nvram_device instance. + */ + nvram_result_t (*disable_create)(const struct nvram_device* device); + + /** + * Writes the contents of a space. If the space is configured with + * NV_CONTROL_WRITE_EXTEND then the input data is used to extend the + * current data. + * + * device - The nvram_device instance. + * index - The space index. + * buffer - The data to write. + * buffer_size - The number of bytes in |buffer|. If this is less + * than the size of the space, the remaining bytes + * will be set to 0x00. If this is more than the size + * of the space, returns NV_RESULT_INVALID_PARAMETER. + * authorization_value - If the space has the + * NV_CONTROL_WRITE_AUTHORIZATION policy, + * then this parameter provides the + * authorization value. Otherwise, this value + * is ignored and may be NULL. + * authorization_value_size - The number of bytes in + * |authorization_value|. + */ + nvram_result_t (*write_space)(const struct nvram_device* device, + uint32_t index, const uint8_t* buffer, + uint64_t buffer_size, + const uint8_t* authorization_value, + uint32_t authorization_value_size); + + /** + * Reads the contents of a space. If the space has never been + * written, all bytes read will be 0x00. + * + * device - The nvram_device instance. + * index - The space index. + * num_bytes_to_read - The number of bytes to read; |buffer| must + * be large enough to hold this many bytes. If + * this is more than the size of the space, the + * entire space is read. If this is less than + * the size of the space, the first bytes in + * the space are read. + * authorization_value - If the space has the + * NV_CONTROL_READ_AUTHORIZATION policy, then + * this parameter provides the authorization + * value. Otherwise, this value is ignored + * and may be NULL. + * authorization_value_size - The number of bytes in + * |authorization_value|. + * buffer - Receives the data read from the space. Must be at least + * |num_bytes_to_read| bytes in size. + * bytes_read - The number of bytes read. If NV_RESULT_SUCCESS is + * returned this will be set to the smaller of + * |num_bytes_to_read| or the size of the space. + */ + nvram_result_t (*read_space)(const struct nvram_device* device, + uint32_t index, uint64_t num_bytes_to_read, + const uint8_t* authorization_value, + uint32_t authorization_value_size, + uint8_t* buffer, uint64_t* bytes_read); + + /** + * Enables a write lock for the given space according to its policy. + * If the space does not have NV_CONTROL_PERSISTENT_WRITE_LOCK or + * NV_CONTROL_BOOT_WRITE_LOCK set then this function has no effect + * and may return an error. + * + * device - The nvram_device instance. + * index - The space index. + * authorization_value - If the space has the + * NV_CONTROL_WRITE_AUTHORIZATION policy, + * then this parameter provides the + * authorization value. Otherwise, this value + * is ignored and may be NULL. + * authorization_value_size - The number of bytes in + * |authorization_value|. + */ + nvram_result_t (*enable_write_lock)(const struct nvram_device* device, + uint32_t index, + const uint8_t* authorization_value, + uint32_t authorization_value_size); + + /** + * Enables a read lock for the given space according to its policy. + * If the space does not have NV_CONTROL_BOOT_READ_LOCK set then this + * function has no effect and may return an error. + * + * device - The nvram_device instance. + * index - The space index. + * authorization_value - If the space has the + * NV_CONTROL_READ_AUTHORIZATION policy, then + * this parameter provides the authorization + * value. (Note that there is no requirement + * for write access in order to lock for + * reading. A read lock is always volatile.) + * Otherwise, this value is ignored and may + * be NULL. + * authorization_value_size - The number of bytes in + * |authorization_value|. + */ + nvram_result_t (*enable_read_lock)(const struct nvram_device* device, + uint32_t index, + const uint8_t* authorization_value, + uint32_t authorization_value_size); +}; + +typedef struct nvram_device nvram_device_t; + +/* Convenience API for opening and closing nvram devices. */ +static inline int nvram_open(const struct hw_module_t* module, + nvram_device_t** device) { + return module->methods->open(module, NVRAM_HARDWARE_DEVICE_ID, + TO_HW_DEVICE_T_OPEN(device)); +} + +static inline int nvram_close(nvram_device_t* device) { + return device->common.close(&device->common); +} + +__END_DECLS + +#endif // ANDROID_HARDWARE_NVRAM_H |