Home | History | Annotate | Download | only in shared 
      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef CHRE_PLATFORM_SHARED_NANOAPP_SUPPORT_LIB_DSO_H_
     18 #define CHRE_PLATFORM_SHARED_NANOAPP_SUPPORT_LIB_DSO_H_
     19 
     20 /**
     21  * @file
     22  * This provides the interface that the dynamic shared object (DSO) nanoapp
     23  * nanoapp support library (NSL) uses to interface with the underlying CHRE
     24  * implementation in a compatible manner.
     25  *
     26  * This header file must retain compatibility with C, and have minimal or no
     27  * dependencies on other CHRE system header files, as it will be used when
     28  * compiling external/dynamic nanoapps.
     29  */
     30 
     31 #include "chre/util/entry_points.h"
     32 
     33 #include <stdint.h>
     34 
     35 #ifdef __cplusplus
     36 extern "C" {
     37 #endif
     38 
     39 //! Special magic value to uniquely identify the nanoapp info structure
     40 #define CHRE_NSL_NANOAPP_INFO_MAGIC  UINT32_C(0x50e69977)
     41 
     42 //! The minor version in the nanoapp info structure helps identify whether
     43 #define CHRE_NSL_NANOAPP_INFO_STRUCT_MINOR_VERSION  UINT8_C(1)
     44 
     45 //! The symbol name expected from the nanoapp's definition of its info struct
     46 #define CHRE_NSL_DSO_NANOAPP_INFO_SYMBOL_NAME  "_chreNslDsoNanoappInfo"
     47 
     48 //! Maximum length of vendor and name strings
     49 #define CHRE_NSL_DSO_NANOAPP_STRING_MAX_LEN  (32)
     50 
     51 /**
     52  * DSO-based nanoapps must expose this struct under a symbol whose name is given
     53  * by CHRE_NSL_DSO_NANOAPP_INFO_SYMBOL_NAME. When the nanoapp is loaded, dlsym()
     54  * will be used to locate this symbol to register the nanoapp with the system.
     55  */
     56 struct chreNslNanoappInfo {
     57   //! @see CHRE_NSL_NANOAPP_INFO_MAGIC
     58   uint32_t magic;
     59 
     60   //! @see CHRE_NSL_NANOAPP_INFO_STRUCT_MINOR_VERSION
     61   uint8_t structMinorVersion;
     62 
     63   //! Set to 1 if this nanoapp is a "system nanoapp" that should not show up in
     64   //! the context hub HAL, likely because it implements some device
     65   //! functionality beneath the HAL.
     66   uint8_t isSystemNanoapp:1;
     67 
     68   //! Set to 1 if this nanoapp runs in tightly coupled memory. This flag is only
     69   //! relevant to platforms that have the ability to run nanoapps within tightly
     70   //! coupled memory.
     71   //!
     72   //! @since minor version 1
     73   uint8_t isTcmNanoapp:1;
     74 
     75   //! Reserved for future use, set to 0. Assignment of this field to some use
     76   //! must be accompanied by an increase of the struct minor version.
     77   uint8_t reservedFlags:6;
     78   uint8_t reserved;
     79 
     80   //! The CHRE API version that the nanoapp was compiled against
     81   uint32_t targetApiVersion;
     82 
     83   //! A human-friendly name of the nanoapp vendor (null-terminated string,
     84   //! maximum length CHRE_NSL_DSO_NANOAPP_STRING_MAX_LEN)
     85   const char *vendor;
     86 
     87   //! A human-friendly name for the nanoapp (null-terminated string, maximum
     88   //! length CHRE_NSL_DSO_NANOAPP_STRING_MAX_LEN)
     89   const char *name;
     90 
     91   //! Identifies the vendor (most significant 5 bytes) and application
     92   uint64_t appId;
     93 
     94   //! Application-specific version number
     95   uint32_t appVersion;
     96 
     97   struct {
     98     chreNanoappStartFunction *start;
     99     chreNanoappHandleEventFunction *handleEvent;
    100     chreNanoappEndFunction *end;
    101   } entryPoints;
    102 };
    103 
    104 /**
    105  * Defined as a placeholder to enable future functionality extension.
    106  *
    107  * @param apiId
    108  * @param apiHandle If this function returns true, this will be set to a pointer
    109  *        to the associated structure containing the API
    110  *
    111  * @return true if the requested API is supported, false otherwise
    112  */
    113 bool chreNslDsoGetApi(uint32_t apiId, void **apiHandle);
    114 
    115 #ifdef __cplusplus
    116 }
    117 #endif
    118 
    119 #endif  // CHRE_PLATFORM_SHARED_NANOAPP_SUPPORT_LIB_DSO_H_
    120