Another device: Epson Moverio BT-100

[Thomas Sohmers]

Hi Guys,

I don't have much experience with the Renesas (Never used a device that had the EV2 before the Moverio), but I have a couple of pairs of Epson Moverio BT-100 Head Mounted Display glasses, and I am trying to build at least 2.3 for it (4.0 would be great, though). Since I am inexperienced with the Renesas SoC (I've only worked deeply with Qualcomm and OMAP), I wanted to know if anyone could help me understand the Renesas chip a bit more, and any major differences in developing with it.

I see there are a lot of people with a "MyPad" device, and sadly pretty much all I know about the Moverio is that it has a EMMA EV2 dual-core processor clocked a 533mhz per core... is there a chance that things will be compatible? I have the kernel source code for the Moverio (which has not been publicly released) along with a "system restore" zip (it uses a very strange recovery system) that also contains the uboot files. I have a basic idea of what I should do, but I am cautious of flashing anything without knowing more.

Thanks in advanced.

[ffxx68]

Hi Thomas,

I don't think your Epson glasses may be compatible (at kernel level) with the "MyPad" (i.e. Livall), or other tablet devices, even though based on the same SoC. This is the issue with the fragmentation we have in Android, where every device, and sometomes even different production batches of exactly the same devices, present different peripherals around the SoC so that the kernel (at least; sometimes Android too) needs changes and recompilation.

I hope someone else here has more info about the Epson glasses.

Glad to have you on board!

 Fabio

[Thomas Sohmers]

Hi Fabio,

Thanks for the quick response... Do you think it would be worth trying to flash something on it? I've been setting up a development environment so I can hopefully try to compile something with Epson's kernel.

It would be great to talk to you more about this... do you use gtalk?

Thanks

[ffxx68]

Yes, I'm on Gtalk too...
I think you can try with Android, but I can't tell if our code works with your kernel...

[Thomas Sohmers]

Sent you a chat request... Thanks

[Dmitriy B.]

I'm sure you can try to load your kernel from SD card using  https://github.com/renesas/emev_tools/tree/master/SD-Update This part is SoC-related and same everywhere, but you will need to find UART and button combination making SoC lookup SD card, for our tablets it is volup+power. (Loading described here  https://github.com/Renesas-EMEV2/RenesasEV2-bootloader/blob/MyPad/README-Renesas )

Just delete install.sh, uImage4, uboot4.bin and ics.tar.gz so you will not flash anything to your device. If memory configuration is somewhat same you have a chance.

Ensure you have UART attached so you will have control of device when it doesnt initialize LCD or video output.

[Thomas Sohmers]

Hi Dmitriy,

I've taken the device apart a couple of times, but have not seen any place that looks like I can tap into to get serial output... Everything is packed pretty tightly in this thing (a bit bigger than a pack of playing cards)

Anyways, I do have an update.zip from Epson containing the stock image of the device (in the same basic format as the SD Update you linked to, there are some added folders in mine)... one other thing I got from Epson was the flashing instructions, which were simply this:

How to update the OS: 

1. Put the microSD card in BT controller.
2. Push three buttons (BACK KEY, 2D/3D KEY and ON/OFF KEY) at the same time.
3. After an LED light shines green, it changes to blue. Blue means that OS is being updated.
4. It takes about 15 minutes to finish OS update. 
5. After OS update finished, LED light would be off.

Since all my previous work has been with more mainstream phones and tablets, I have never seen a recovery/update system like this, so this is an interesting learning experience. I just tried building, and my device did not have all of the OMF and SGX blobs and libraries that it tried to pull, and the build failed after I tried a couple different make options.

OK Question time: Should I try to load a new kernel in the file format provided by Epson, or should the one you provided work fine? Should I try combining the Epson provided kernel with anything, or are there any specific modifications I should make? What do you think are the chances I can get a Gingerbread build working?

Thanks

[Dmitriy B.]

but have not seen any place that looks like I can tap into to get serial output... Everything is packed pretty tightly in this thing (a bit bigger than a pack of playing cards) 

Try to remove PCB from case and look at backside of PCB, there you will see dosen of testpoints. Example (NOT ev2 tablet, but we have pretty much same):  http://linux-sunxi.org/File:LY-F1_pcb_front.jpg front side is pretty crowded,  http://linux-sunxi.org/File:LY-F1_pcb_back.jpg backside has tons of testpoints and also buttons and hdmi are moved there from front side. 

Another idea is to look up for unpopulated flat flex cable connectors, our EV2 tablet Rena3 has UART located there. See serial debugging topic around here.

Should I try to load a new kernel in the file format provided by Epson, or should the one you provided work fine?  

Also, whats the file format of Epson update package? How you can see at emev-tools, we have uboot.bin sdboot.bin and uImage. When SD card boot combination pressed, SoC reads MBR from SD card, if it is there and first partition is FAT16/32, it reads sdboot.bin and executes it in SRAM directly on SoC, without DDR ram for now, then sdboot launches U-Boot from uboot.bin and standard procedure of loading goes (essential hw including DDR gets initialized and U-Boot executes boot script commands). 

First part (MBR reading and sdboot.bin execution) is hardcoded in each EV2 SoC. You can check it out in datasheet here https://github.com/Renesas-EMEV2/RenesasEV2-bootloader/blob/MyPad/R19UH00356EJ0800_1chip.pdf?raw=true

I just tried building, and my device did not have all of the OMF and SGX blobs and libraries that it tried to pull, and the build failed after I tried a couple different make options. 

Forget about SGX and blobs for now, you dont need them for simple 2D android. For successfull build and operation of device first you need to have libhardware/hardware_legacy that will have framebuffer and other wrappers.

Still, without UART trying to run something homebrew on device is pretty useless, because you will not have feedback for debugging.

Hope this helps, Dmitriy Beykun.

[ffxx68]

A UART isn't stricly needed, except for debugging the early uboot stages.
Once booted into Android, you can attach a USB cable and used adb to access the device.
I agree with Dmitryi to skip blob pulling. It should still work...

[alexis Se]

Hello I unearths this topic because i found the file of the rom and the kernel :

rom : https://mega.co.nz/#!4NAGxYRQ!ONrMAzR0tDrQ-zrUq_YM9a_U928NG2GObuOvLTfRNxE

Kernel : https://mega.co.nz/#!EYxSkKBQ!sx2TKQmVReXyL3UV_KCkVRjBr1ltxPcH7K6IrnCPYtY

Thanks for your help :)

[ffxx68]

Great - ever tried a rebuild?
Are the glasses still sold?