Samsung Z1 (samsung-kiran)

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Samsung Z1
Samsung Z1 running xfce4
Samsung Z1 running xfce4
Manufacturer Samsung
Name Z1
Codename samsung-kiran
Released 2015
Category testing
Original software Tizen 2.4.0 (Magnolia)
postmarketOS kernel 3.10.17
Hardware
Chipset Spreadtrum SC7727S
CPU 2x ARM Cortex-A7
GPU Mali-400
Display 480x800 TFT
Storage 4 GB
Memory 768 MB
Architecture armv7
Non-Android based device
Features
USB Networking
Works
Flashing
Works
Touchscreen
Works
Display
Works
WiFi
Works
FDE
Mainline
Broken
Battery
Works
3D Acceleration
Audio
Works
Bluetooth
Camera
GPS
Mobile data
SMS
Calls
USB OTG
Broken
NFC
Unavailable
Sensors
Accelerometer
Magnetometer
Unavailable
Ambient Light
Unavailable
Proximity
Unavailable
Hall Effect
Unavailable
Misc
Ir TX
Unavailable
TrustZone



Contributors

  • peremen

Maintainer(s)

Users owning this device

How to enter flash mode

Similar as Samsung's Android counterparts:

  • Hold Power + Home + Volume Down buttons to enter flash mode.
  • Hold Power + Home + Volume Up buttons to enter recovery mode.

/proc/cmdlines for different power on reasons:

  • Normal mode: mem=768M ram=768M root=/dev/mmcblk0p24 ro rootfstype=ext4 rootwait bootmode=normal pwron.reason=0x0 ...
  • Recovery mode: mem=768M ram=768M root=/dev/mmcblk0p24 ro rootfstype=ext4 rootwait systemd.unit=recovery-mode.target pwron.reason=0x0 ...
  • Plugging in charger: mem=768M ram=768M root=/dev/mmcblk0p24 ro rootfstype=ext4 rootwait systemd.unit=charging-mode.target pwron.reason=0x0 ...

Installation/Known Problems

Technically similar as Samsung's Android counterparts, however, there are some caveats. The stock Tizen boot image uses dzImage, basically vmlinuz + Spreadtrum dtb binary (can generate using dtbtool-sprd) with custom header. Because Tizen kernel does not enable initramfs, and S-BOOT on this device seems to lack support of it, we are using isorec. The current postmarketOS kernel will use KERNEL to store dzImage, RAMDISK to store initramfs. Make sure to flash both partitions when going from Tizen to postmarketOS and vice versa.

Booting non-stock kernel image will show a red exclamation mark on the top left of boot screen.

The sprdfb driver of Tizen kernel is different from Android devices using the same SoC: it has DRM driver for this SoC, predates what is in the mainline. Graphics memory management seems to be done using libtbm in Tizen and X.org proprietary driver. There is no memory region for sprdfb driver mentioned in the .dts file, thus mmap() to the framebuffer returns only an error. The postmarketOS kernel patch manually includes the memory region in the .dts file and modifies the memory allocation to make framebuffer work. Lack of proper Spreadtrum datasheet makes further progress hard.

Components

See also