Epson Moverio BT-200 (embt2ws)

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Epson Moverio BT-200
CHANGE_ME
CHANGE_ME
Manufacturer Epson
Name Moverio BT-200
Codename embt2ws
Released 2014
Category testing
Original software Android
Original version 4.04 (Kernel 3.0.21, U-Boot 1.1.4)
Hardware
Chipset TI OMAP 4460
CPU 2x1.2 GHz Cortex A9
GPU PowerVR SGX540
Display 960x540 see through glasses U-Boot 1.1.4
Storage 8GB eMMC + uSD slot
Memory 1024 MB
Architecture armv7
Type Glasses
Features
USB Networking
Flashing
Touchscreen
Display
WiFi
FDE
Mainline
Battery
3D Acceleration
Audio
Bluetooth
Camera
GPS
Mobile data
SMS
Calls
USB OTG
NFC
Sensors
Accelerometer
Magnetometer
Ambient Light
Proximity
Hall Effect
Barometer
Power Sensor
Misc
Keyboard
Touchpad
USB-A
HDMI/DP
Ir TX
FOSS bootloader


This device is based on the TI OMAP 4460.
See the SoC page for common tips, guides and troubleshooting steps

Contributors

  • Andi

Users owning this device


How to influence/change boot order

Boot order is eMMC, USB, UART, uSD. That can be overwritten by software until the next cold boot:


eMMC boot can be skipped using a 470 Ohm resistor from eMMC DAT 0 to GND on powerup. So that would be a recovery if loader on eMMC is broken. Bt200-emmc-dat0.jpg

Accessing serial console in original system

JP1 (soldering jumper on the back side = gpio-138) needs to be shorted to enable serial console on factory kernel/u-boot. (4 2.54mm pitched holes). Voltage level is 1.8V

Bt200-uart.jpg

Boot process of the original system

Xloader is located at sector 256 and loads U-Boot from sector 512 as a raw headerless binary on the same device as Xloader also was loaded from. CONFIG_SYS_TEXT_BASE of such a u-boot has te be set to 0x80e80000. Size limit is 0x60000 bytes.

Factory U-Boot tries to load a sdboot.scr from the first partition (which must bet FAT) of the uSD card which is executed if some requirements are met, if not, normal boot from eMMC is done. Fastboot can be activated via commandline.

How to enter flash mode

Installation

System can be installed on uSD card. To be able to boot that you need to either

  • zero the xloader and u-boot area of the eMMC
  • hack the integrated u-boot bootcmd to ignore check_code test results to boot the sdboot.scr
  • use one of the methods to temporarily change boot order
  • use u-boot commandline to manually load stuff (which can also be a modern u-boot)

See also

  • Factory kernel
  • [1] branch epson-6.1, mainling attempts
  • [2] branch v2022.10-epson u-boot mainling attempts