Samsung Galaxy A21s (samsung-a21s)
 Samsung Galaxy A21s running Phosh | |
| Manufacturer | Samsung |
|---|---|
| Name | Galaxy A21s |
| Codename | samsung-a21s |
| Model | SM-A217F |
| Released | 2020 |
| Type | handset |
| Hardware | |
| Chipset | Samsung Exynos 850 |
| Display | 720x1600 PLS LCD |
| Storage | 32/64/128 GB eMMC 5.1 + microSDXC |
| Memory | 3/4/6 GB LPDDR4X |
| Architecture | aarch64 |
| Software | |
Original software  The software and version the device was shipped with. |
Android (One UI) 10 (One UI 2) |
Extended version The most recent supported version from the manufacturer. |
Android (One UI) 12 (One UI 4.1) |
| FOSS bootloader | no |
| postmarketOS | |
| Category | testing |
Mainline Instead of a Linux kernel fork, it is possible to run (Close to) Mainline. |
yes |
| Device package |
device-samsung-a21s out-of-tree |
| Kernel package |
linux-samsung-a21s out-of-tree |
Flashing Whether it is possible to flash the device with pmbootstrap flasher. |
Works
|
|---|---|
USB Networking After connecting the device with USB to your PC, you can connect to it via telnet (initramfs) or SSH (booted system). |
Works
|
Internal storage eMMC, SD cards, UFS... |
Works
|
SD card Also includes other external storage cards. |
Broken
|
Battery Whether charging and battery level reporting work. |
Broken
|
Screen Whether the display works; ideally with sleep mode and brightness control. |
Works
|
Touchscreen |
Works
|
| Multimedia | |
3D Acceleration |
Works
|
Audio Audio playback, microphone, headset and buttons. |
Broken
|
Camera |
Broken
|
Camera Flash |
Broken
|
| Connectivity | |
WiFi |
Broken
|
Bluetooth |
Broken
|
GPS |
Broken
|
NFC Near Field Communication |
Broken
|
| Modem | |
Calls |
Broken
|
SMS |
Broken
|
Mobile data |
Broken
|
| Miscellaneous | |
FDE Full disk encryption and unlocking with unl0kr. |
Broken
|
USB OTG USB On-The-Go or USB-C Role switching. |
Broken
|
| Sensors | |
Accelerometer Handles automatic screen rotation in many interfaces. |
Broken
|
Proximity |
Broken
|
Contributors
Users owning this device
- Bruhboy666dev
- Kotik (Notes: CrDroid 11.3, Android 15(I still don't upgraded CrDroid version), 4/64.)
- Leo
- Lx.niko
- Madhaxbro (Notes: SM-A217F, runs LineageOS. Basic modern Smartphone, capable CPU and weak GPU. The SoC is supported in mainline. Has uniLoader support.)
- RiskyGUY22
- Wojtekojtek (Notes: Aftermarket screen)
- Zerkalo (Notes: not tested yet)
How to unlock bootloader
 |
WARNING: Unlocking the bootloader will wipe all data and may void the warranty |
- Connect the device to a Wi-Fi network.
- Enable Developer Options by pressing the “Build Number” option at least 7 times, in the “Settings” app within the “About” menu
- Within the “Settings” app go to “Date and Time” and change the date to be 2 years in the past
- Reboot the device
- Go to the Developer Options menu in the “Settings” app and enable OEM unlock
- Power off the device, and boot it into download mode:
- With the device powered off, hold Volume Up + Volume Down then connect USB cable to PC.
- Now, click the button that the onscreen instructions correlate to “Device unlock mode” and/or “Unlock Bootloader”.
- Your device will reboot and format all user data, you may now unplug the USB cable from your device.
- Run through Android Setup, it is crucial that you connect to a Wi-Fi network when setting up the device
- Re-enable Development settings by clicking the “Build Number” option 7 times, in the “Settings” app within the “About” menu, and verify that “OEM Unlock” is still enabled in the “Developer options” menu.
How to install a custom recovery
- Unplug device from computer and power off
- Simultaneously plug device into computer while holding Volume Up + Volume Down
- Follow on screen instructions to enter download mode
- Download the recovery.img here: https://mirrorbits.lineageos.org/full/a21s/20260909/recovery.img
- Assuming you are on Linux, run this command and after it is finished immediately hold Volume Up + Power until you enter recovery mode
$ sudo heimdall flash --RECOVERY recovery.img
- Now press Advanced -> Enter fastboot and continue to Installation.
Installation
Use pmbootstrap to build your own installation image. NOTE: This device was tested using phosh ui.
$ pmbootstrap init
$ pmbootstrap install
$ pmbootstrap flasher flash_vbmeta
$ pmbootstrap flasher flash_dtbo
$ pmbootstrap flasher flash_kernel
$ pmbootstrap flasher flash_rootfs