* Introduction
* Hardware
* Software architecture and Integration details
* STM proprietary libraries
* Copyright
The STM Android Teseo Hardware Abstraction Layer (HAL) defines a standard interface for the STMicroelectronics (STM) Teseo family of Global Navigation System ICs. The Teseo HAL library is packaged into modules files (.so) and loaded by the Android system at the appropriate time.
Currently supported GNSS receivers are: STA8088, STA8089/STA8090
The STM Teseo HAL provides the following features:
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Location
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Satellite information
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Geofencing
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Real Time AGNSS (see section STM proprietary libraries)
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Predictive Assisted GPS 7 (see section STM proprietary libraries)
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Support for raw measurements and navigation messages
The [HiKey960 from Lenovator] has been used as the reference development platform for the Teseo HAL. If you are using another development platform, be sure that you can connect it properly to the UART of your Teseo chip.
In the following sections, the terms Hikey and Teseo Chip refers, respectively, to the HiKey960 development platform and to any GNSS IC of the STMicroelectronics Teseo family.
The Teseo HAL is written in C++ language using object-oriented design. The HAL Manager module is called during the boot phase to instantiate and initialize objects, signals and slots. The HAL Location Service Proxy module handles the events sent by the Android Location Service and by the other HAL modules.
As soon as the navigation is started by an application, the HAL Virtual device starts to parse and to decode the NMEA data coming from the Teseo chip. It updates its own data model, and then send updates to the HAL location service proxy and to any other module which requires data updates as well.
When not used by any application the Teseo chip isn’t sleeping. It is up to you to wake up and suspend the Teseo chip when the navigation is started and stopped.
You must place the source in the correct location in the android source tree. Then you have to download the source from the repositories. The following commands will do all:
$ mkdir <AOSP_DIR>/hardware/stm
$ cd <AOSP_DIR>/hardware/stm
<AOSP_DIR>/hardware/stm $ git clone https://github.com/STMicroelectronics/STADG_Teseo_Android_HAL.git teseo
<AOSP_DIR>/hardware/stm $ cd teseoOnce you have downloaded all the source code, you have to customize your target device build configuration to integrate the STM Teseo HAL. You need at least to:
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Require the
gps.$(TARGET_BOARD_PLATFORM)library in yourPRODUCT_PACKAGESvariable, -
Add the gps xml permission file and the gps configuration file in the
PRODUCT_COPY_FILESvariable.
To do so, add the following lines in your target device device-hikey960.mk file:
PRODUCT_COPY_FILES += \\
frameworks/native/data/etc/android.hardware.location.gps.xml:system/etc/permissions/android.hardware.location.gps.xml \\
device/linaro/hikey/etc/gps.conf:system/etc/gps.conf
PRODUCT_PACKAGES += gps.hikey960If you are not using Hikey, you must adapt the gps.hikey960 name to your board and the path to your gps.conf file.
You should use the template available in hardware/stm/teseo/etc/gps.conf to write your own gps.conf file.
For the Hikey you also need to configure SELinux to allow access to the tty device from the HAL. To do so, add the following line to device/linaro/hikey/sepolicy/file_contexts:
/dev/ttyXX u:object_r:console_device:s0
And the following line to device/linaro/hikey/ueventd.hikey.rc:
/dev/ttyXX 0660 gps system
where /dev/ttyXX is the serial console where the Teseo chip sits.
Finally to ease development, add this line to device/linaro/hikey/hikey960/BoardConfig.mk:
BOARD_KERNEL_CMDLINE := $(BOARD_KERNEL_CMDLINE) androidboot.selinux=permissive
And this line to device/linaro/hikey/vendorsetup.sh:
add_lunch_combo hikey-eng
You just have to issue the following command in the android environment:
<AOSP_DIR> $ make -j32
The build should contain the following file /system/lib64/hw/gps.hikey960.so.
The real-time AGNSS is able to provide the approximate current time, the ephemerides, the almanacs to the Teseo chip GNSS engine in a time frame less than the usual time (about 30 seconds) needed to download real ephemeris from the sky. This reduces considerably the time to get fix especially in critical environments when the ephemeris download time could be very long. Real-time AGNSS requires a network connection to download assistance data from the server.
This server based assistance allows fast and accurate GPS performances thanks to a 8KB bi-weekly data transfer. Starting from this downloaded payload, the Teseo chip is capable of computing the ephemeris for up to 14 days, with very high accuracy, for the complete GPS and GLONASS constellations. Predictive AGPS requires a network connection to download assistance data from the server.
The Teseo chip is able to report raw measurements data and navigation messages through the HAL GNSS measurements interface. This is available for GPS signals. Please note that the Teseo chip must use a dedicated binary image enabling Carrier Phase measurements.
Please note that the release of STM proprietary libraries is subject to signature of a Software License Agreement (SLA) or of a Non Disclosure Agreement (NDA); please contact an STMicroelectronics sales office and representatives for further information.
Copyright (C) 2018 STMicroelectronics
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.