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 right Distribution Package for your selected microprocessor device. See Distribution_Package.
To be able to execute following instructions you need to work from your distribution root directory and initialise your environment:
source build/envsetup.sh
lunch aosp-<BoardId>-userdebug
2 Layout configuration[edit source]
It is possible to configuration the memory layout. The file android_layout.config located device/stm/<STM32Series>/layout contains all the necessary data.
When changes is done you need to reload the environment with:
source build/envsetup.sh
lunch aosp-<BoardId>-userdebug
2.1 Memory type[edit source]
To adapt your build to the memory you desire, you must change in the file android_layout.config the parameter PART_MEMORY_TYPE.
For example the possible values can be:
- sd
- emmc
2.2 Memory size[edit source]
To adapt your build to the size of your memory you can change in the file android_layout.config the parameter PART_MEMORY_SIZE.
For example the possible values can be:
- 4GiB
- 8GiB
This value must match the parameter at the end of the file that looks like PART_<Memory size>_MEMORY_MAX_SIZE
It may be necessary to change the value attach to this parameter. For example:
PART_8GiB_MEMORY_MAX_SIZE 7432M x1 sd
The 7536M must be adapt if your memory is less than its definition.
To find the correct value execute:
sgdisk -p /dev/mmcblk<x>
It will output something looking like:
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)
First line show the microSD card available size: here 15433728 sectors.
To calculate the size in MiB:
size = (NbSectors * SectorSize) / 1024 / 1024 In this example: (15433728 * 512) / 1024 / 1024 = 7536 MiB
Report this value for the parameter PART_8GiB_MEMORY_MAX_SIZE
PART_8GiB_MEMORY_MAX_SIZE 7536M x1 sd
You can refer to the README file in the same folder for more details.
2.3 Partition size[edit source]
If you decide to change the size of some partition you need to change in the file android_layout.config.
You need to adapt all parameter that looks like
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)
When this is done you also need to adapt every FlashLayout_*.tsv under device/stm/<STM32Series>/layout/programmer to match your changes.
For that purpose, you can use the script device/stm/<STM32Series>/script/layout/build_tsv.py.
3 Audio configuration[edit source]
The configuration file audio.stm.xml is stored in device/stm/<STM32Series>/<BoardId>/media/audio
For more details please refer to How to change audio device for Android
4 Lights configuration[edit source]
The configuration file lights.stm.xml is stored in device/stm/<STM32Series>/<BoardId>/lights
The target of this file is to associated the list of leds with the Android light IDs:
- notifications
- attention
- backlight
- keyboard
- buttons
- battery
- bluetooth
- wifi
First you have to identify the list of available leds (it's recommended to stubbed the list of lights 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 you can associate the following Android light IDs with the correct label.
5 Thermal configuration[edit source]
The configuration file thermal.stm.xml is stored in device/stm/<STM32Series>/<BoardId>/thermal
Thermal information can be returned for the following list of temperature types:
- CPUx (one index for each CPU)
- GPU
- Battery
- Skin (external part of the device)
First you have to identify the list of available thermal zones (it's recommended to stubbed the list of thermal data 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 types (example with two thermal zones with indexes 0 and 1) :
cat /sys/class/thermal/thermal_zone0/type cat /sys/class/thermal/thermal_zone1/type
You can check for each zone the list of trip point available (not systematically present, example with 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
From this stage, you can update in consequence the configuration file.
- If no information is available, you can stubbed adding fixed values
stub="1" - If a thermal zone is associated to one or several temperature types
stub="0"- case without trip point data, you have to fixed the values in the file
- case with trip point data, you have to 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.
The Bluetooth is enabled in device/stm/<STM32Series>/<BoardId>/BoardConfig.mk
BOARD_HAVE_BLUETOOTH := true BOARD_HAVE_BLUETOOTH_LINUX := true
The path of the configuration file overlay bdroid_buildcfg.h must be also added:
BOARD_BLUETOOTH_BDROID_BUILDCFG_INCLUDE_DIR ?= device/stm/<STM32Series>/<BoardId>/network/bt
The Android Bluetooth stack (located in system/bt) can be configured thanks to the file device/stm/<STM32Series>/<BoardId>/network/bt/bdroid_buildcfg.h.
It must at least contain the definition of the Class of Device (CoD) (see more information in the Bluetooth Specification[1])
#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 selected 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
If you want to disable it, add the following line in bdroid_buildcfg.h:
#define BTA_PAN_INCLUDED FALSE
More details in Android Bluetooth[2].
7 Wi-Fi configuration[edit source]
The configuration is stored in device/stm/<STM32Series>/<BoardId>/network/wifi.
You can change various configuration:
- p2p
- wpa supplicant
- dhcp
For more details please refer to How to change Wi-Fi device for Android
8 Modify Android distribution[edit source]
You can adapt the list of changes performed during the <STM32Series>setup (ex: stm32mp1setup for STM32MP1 series) modifying the file android_patch.config available in device/stm/<STM32Series>/patch/android/
For that purpose, before any modification, you have to clear the current configuration:
<STM32Series>clear -p
From this stage, you can adapt the file (add or/and remove list of commits and patches).
Some rules shall be followed for added patches:
- Patch files shall be added with the relative path to
device/stm/<STM32Series>/patch/android/directory. - Patch files shall be added without the suffix .patch
- Patch shall be added in the correct order
Some rules shall be followed for removed patches:
- Test new configuration on the targeted directory applying patches manually (re-generate them if required)
- Do not remove patches and commits with
do not modifymention
Then you can apply the new configuration:
<STM32Series>setup
From this stage, you have to rebuild the distribution to take into account your changes:
make -j
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