This articles explain how you can customize the STM32MPU distribution for Android™. It's intent to be used by distribution package users.
1. Prerequisites[edit source]
The environment used must have been installed using the Distribution Package adapted to your microprocessor device. See Distribution_Package.
To execute the following instructions, go to your distribution root directory and initialize your environment:
source build/envsetup.sh
lunch aosp_<BoardId>-userdebug
2. Layout configuration[edit source]
The memory layout can be configure through the android_layout.config file located in device/stm/<STM32Series>/layout. It contains all the necessary data.
When changes are complete, reload the environment:
source build/envsetup.sh
lunch aosp_<BoardId>-userdebug
2.1. Memory type[edit source]
To adapt your build to the required memory, change the PART_MEMORY_TYPE parameter in the android_layout.config file. PART_MEMORY_TYPE values can be:
- sd
- emmc
2.2. Memory size[edit source]
To adapt your build to your memory size, change the PART_MEMORY_SIZE parameter in the android_layout.config file. PART_MEMORY_SIZE values can be:
- 4GiB (4 Gbytes)
- 8GiB (8 Gbytes)
Its value must match the parameter of name PART_<Memory size>_MEMORY_MAX_SIZE, located at the end of the file.
It might need to be changed. For example:
PART_8GiB_MEMORY_MAX_SIZE 7432M x1 sd
The 7536M must be adapted if your memory size is lower that the value defined.
To find the correct value, execute the command below:
sgdisk -p /dev/mmcblk<x>
It displays the following information:
Disk /dev/mmcblk0: 15433728 sectors, 7.4 GiB Logical sector size: 512 bytes Disk identifier (GUID): XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXX Partition table holds up to 128 entries First usable sector is 34, last usable sector is 15433694 Partitions will be aligned on 2-sector boundaries Total free space is 0 sectors (0 bytes)
The first line show the microSD card available size: here 15433728 sectors.
To calculate the size in MiB (Mbytes):
size = (NbSectors * SectorSize) / 1024 / 1024 In this example: (15433728 * 512) / 1024 / 1024 = 7536 MiB
Report this value in PART_8GiB_MEMORY_MAX_SIZE:
PART_8GiB_MEMORY_MAX_SIZE 7536M x1 sd
For more details, refer to the README file located in the same folder.
2.3. Partition size[edit source]
To change the size of a partition, modify it in the android_layout.config file.
Adapt the following parameters:
PART_<NAME> <PART_SIZE> <PART_NB> <PART_LABEL> <PART_SUFFIX> <PART_ENABLE> NAME: name of the local variable (last partition MUST start with PART_LAST_) PART_SIZE: as xxxMB or xxxKB or xxxGB PART_NB: number of instances of partition (x1 or x2) PART_LABEL: name of the partition label PART_SUFFIX (optional): name of the suffix in case PART_NB equal x2 (_a/_b by default) PART_ENABLE (optional): device for which the partition is only applicable (sd)
Then adapt every FlashLayout_*.tsv under device/stm/<STM32Series>/layout/programmer to match your changes.
To do this, use the device/stm/<STM32Series>/script/layout/build_tsv.py script.
3. Audio configuration[edit source]
The audio.stm.xmlconfiguration file is stored in device/stm/<STM32Series>/<BoardId>/media/audio.
Refer to How to change audio device for Android for more details.
4. Light configuration[edit source]
The lights.stm.xml configuration file is stored in device/stm/<STM32Series>/<BoardId>/lights.
This file allows associating the list of LEDs with the Android light IDs:
- notifications
- attention
- backlight
- keyboard
- buttons
- battery
- bluetooth
- wifi
First identify the list of available LEDS (it is recommended to stub the list of lights by adding device="stub").
Open a terminal on the device:
adb shell
Get the list of available labels:
ls /sys/class/leds/
In the device-tree associated to your device, you can check the list of <label> names in the <led> structure.
Then associate the following Android light IDs with the correct label.
5. Thermal configuration[edit source]
The thermal.stm.xml configuration file is stored in device/stm/<STM32Series>/<BoardId>/thermal.
Thermal information can be returned for the following temperature types:
- CPUx (one index for each CPU)
- GPU
- Battery
- Skin (external part of the device)
First identify the list of available thermal zones (it is recommended to stub the list of thermal data by adding stub="1" and adding fixed values for threshold,shutdown and threshold_vr_min).
Open a terminal on the device:
adb shell
Check the list of available zones:
ls /sys/class/thermal/
Check each thermal zone type. Below the example corresponding to the case of two thermal zones with indexes 0 and 1:
cat /sys/class/thermal/thermal_zone0/type cat /sys/class/thermal/thermal_zone1/type
For each zone, check the list of available trip points (not systematically present). Below the example corresponding to the case of two trip points with indexes 0 and 1 for thermal zone 0:
cat /sys/class/thermal/thermal_zone0/trip_point_0_type cat /sys/class/thermal/thermal_zone0/trip_point_1_type
Update the configuration file according to the information returned:
- If no information is available, you can stub the list of thermal data by adding fixed values
stub="1" - If a thermal zone is associated to one or several temperature types:
stub="0"- No trip point data: fix the values in the file.
- Trip point data: put all data at 0 and add each trip index and type values in the file.
6. Bluetooth configuration[edit source]
The configuration is stored in bdroid_buildcfg.h located in device/stm/<STM32Series>/<BoardId>/network/bt.
Bluetooth is enabled in device/stm/<STM32Series>/<BoardId>/BoardConfig.mk:
BOARD_HAVE_BLUETOOTH := true BOARD_HAVE_BLUETOOTH_LINUX := true
Add the path of the configuration file overlay bdroid_buildcfg.h:
BOARD_BLUETOOTH_BDROID_BUILDCFG_INCLUDE_DIR ?= device/stm/<STM32Series>/<BoardId>/network/bt
The Android Bluetooth stack (located in system/bt) can be configured through the device/stm/<STM32Series>/<BoardId>/network/bt/bdroid_buildcfg.h file.
It must at least contain the definition of the Class of Device (CoD) (refer to the Bluetooth Specification[1] for additional information):
#define BTA_DM_COD {0x5A, 0x01, 0x1C}
Additionally, it can contain the Bluetooth Stack profile configuration. If a variable is not set in this file, the default configuration is used in the stack.
By default, all the profiles are selected (see system/bt/include/bt_target.h).
Example for the PAN profile:
#ifndef BTA_PAN_INCLUDED #define BTA_PAN_INCLUDED TRUE #endif
To disable it, add the following line in bdroid_buildcfg.h:
#define BTA_PAN_INCLUDED FALSE
Refer to Android Bluetooth[2] for more details
7. Wi-Fi configuration[edit source]
The configuration is stored in device/stm/<STM32Series>/<BoardId>/network/wifi.
You can change the following parameters:
- p2p
- wpa supplicant
- dhcp
Refer to How to change Wi-Fi device for Android for more details.
8. Modification of the Android distribution[edit source]
The list of changes performed during the <STM32Series>setup (ex: stm32mp1setup for STM32MP1 series) can be adapted by modifying the android_patch.config available in device/stm/<STM32Series>/patch/android/ file.
First retrieve the original configuration:
<STM32Series>clear -p
Then adapt the file (add or/and remove list of commits and patches).
Some rules must be respected for adding patches:
- Patch files shall be added with the relative path to
device/stm/<STM32Series>/patch/android/directory. - Patch files shall be added without the .patch suffix.
- Patches shall be added in the correct order.
Some rules must the respected for removing patches:
- Test the new configuration on the targeted directory by applying the patches manually (generate them again if required).
- Do not remove patches and commits with
do not modifymention.
When this is done, apply the new configuration:
<STM32Series>setup
Then rebuild the distribution to take into account your changes:
make -j
9. References[edit source]