Epson Moverio BT-200 (epson-embt2ws)

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Epson Moverio BT-200
CHANGE_ME
CHANGE_ME
Manufacturer Epson
Name Moverio BT-200
Codename epson-embt2ws
Released 2014
Category testing
Pre-built images no
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
Storage 8GB eMMC + uSD slot
Memory 1024 MB
Architecture ARMv7
Type Glasses
Features
USB Networking
Works
Flashing
Display
WiFi
Works
FDE
Mainline
Works
Battery
Broken
3D Acceleration
Audio
Works
Bluetooth
Partial
Camera
Broken
GPS
Partial
Internal storage
Works
USB OTG
Sensors
Accelerometer
Works
Magnetometer
Works
Ambient Light
Proximity
Hall Effect
Power Sensor
Misc
Built-in DVB
Camera Flash
Keyboard
Touchpad
Ir RX
Stylus
Memory Card
Haptics
Ethernet
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: Commands in U-Boot, similar could be done via /dev/mem

mw.l 0x4A326A0C 0xCF00AA01
mw.l 0x4A326A10 0xC
mw.w 0x4A326A14 0x0
mw.w 0x4A326A16 0x43
mw.w 0x4A326A18 0x45
mw.w 0x4A326A1A 0x05
mw.w 0x4A326A1C 0x0
mw.w 0x4A326A1E 0x0
mw.l 0x4A326A00 0x4A326A0C

and then warm-reboot (e.g. reset button or reset command in newer u-boots).

If you want to reorder the boot order temporarily, you can do that from the original system if it is rooted, use setup-bootchoice from https://github.com/akemnade/bt200tools.

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 the md5sum of the first line is 92b12a37d1913ac41d2956120a475aca, 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 (after doing a backup)
  • hack the integrated u-boot bootcmd to ignore check_code test results to boot the sdboot.scr (e.g. via usb mass storage mode via ums command): there is some
     checkcode; if test $? -eq 1
    in the builtin u-boot env, replace that by e.g.
     checkcode; if test 33 -eq 1
  • 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 u-boot wiki)

See also

  • Factory kernel
  • [1] branch epson-6.1, mainling attempts (look also at the corresponding wiki)
  • [2] branch v2022.10-epson u-boot mainling attempts (look also at the corresponding wiki)