Bootable ext4 Micro SDHC card reported as “Damaged SD card” by Android phone

TL/DR – if you have ext3/4 partition on your Micro SDHC card (e.g. you boot some Linux from it) and then try to put this card into Android phone, it will complain about “Damaged SD card” until you erase (zero out) bootloader from ext3/ext4 partition.

 

Android phone complains about damaged sdcard after bootloader installation. But not just any bootloader. It actively dislikes any bootloader on ext3/4 partions. It complains and refuses to mount sdcard. If you force mount in terminal/ADB - it will mount, but bootloader will be corrupted (do not know exactly why, but has to do something with security and signing of Android system bootloader). My card is multi-partition, and while I mount PRT1 (FAT32), Android corrupts Partition Boot Record (PBR) on PRT4 (EXT4). To avoid this problem I zeroed out PBR on PRT4 (where Linux resides) and Android immediately stopped compaining about the card. Mounts it, scans it, uses for camera/gallery storage, etc.

NOTICE AGAIN: ZERO OUT EXT3/4 PARTITION BOOTSECTOR to allow mounting of FAT32 partition in Android. Strange, I know. I think Android is crazy cautious about EXT3/4 bootloaders, to prevent booting unsigned ROMs from any EXT3/4 filesystem, no matter if it is on internal or external sdcard.

I couldn’t google up anything on this topic, and spent couple of days understanding and then solving this issue. Here goes more detailed explanation. Hopefully it saves time to other people trying to read bootable FAT32/EXT4 card in Android (keywords: USB multi-boot, Micro SDHC, Android, SD Card is Damaged, bootloader, grub, mbr)

I use Sandisk Ultra Micro SDHC (UHS-1) 64 GB card in my phone (LG Optimus 3D, ICS 4.0.4) and in compact Lexar USB3.0 card reader on a keychain.

On Android, I use excellent app DriveDroid to expose bootable IMGs to PC via USB cable (mostly Windows Defender Offline x32/x64, and Windows 8 Install/Recovery). But I also use USB 3.0/MicroSDHC reader with  multiple ISOs, Porteus Linux and a real installation of Linux Mint on EXT4. It is fast enough. Boots in a minute. Speed is OK, feels like a slow laptop HDD of 2010.

Card is partitioned into:
MBR  with BOOTMGR (here and in other cases, installed with BOOTICE (free Windows app) 
PRT1: FAT32 -50GB with BOOTMGR (NT6) - Largest partition for data - compatibile with most devices
PRT2: NTFS - 1GB NTLOADER*
PRT3: NTFS - 1GB NTLOADER*
PRT4: EXT4 - 12GB - used to be GRUB2, now empty boot sector

*PARTITIONS 2 and 3 are small stubs between FAT32 (max space) and EXT4 (limited space at the end of  card). I figured that one day I might want to reduce FAT32 and experiment with another or two partitions, without having to move EXT4. I guess PRT2 and PRT3 are not relevant further to this topic.

I played quite a lot with the PRT1, it boots Windows 8 BootMgr, and from there I have added syslinux and grub4dos and can go between them, chainloading each other in circles.  What is interesting, is that I can put any bootloader on FAT32 (PRT1) and it will not affect my card when I put it into Android phone.

THE PROBLEM BEGAN AFTER INSTALLATION OF LINUX ON PRT4(EXT4). Android refuses to mount the card. I forced it through terminal with
su
mount -t vfat /dev/block/mmcblk1p1 /mnt/sdcard/_ExternalSD

File explorers then can see the card but message about Damaged SD Card still hangs there in notifications. When I unmount the card and try booting Linux, it freezes silently. Turns out bootloader of GRUB2 in PRT4 is corrupted.

In order to solve this problem, I booted Mint's vmlinuz/initrd directly from GRUB4DOS on PRT1 and reinstalled GRUB2 on PRT4, then used BOOTICE to copy PBR from EXT4 partition (512 bytes) and save it into file on FAT32. Now I can boot it from BOOTMGR directly into GRUB2.mbr file and use Linux. Then, I used BOOTICE's sector editor functionality, to fill first sector (512 bytes) of PRT4 with zeroes. After doing, this, Android stopped compaining about the card and happily mounts FAT32 partition.

Enjoy, and share in the comments your weird and geeky setup. I am really interested in miniscule and versatile computers and what you use them for.

Windows Mobile 7 device specifications

Believe or not believe? I tend to believe, seeing that HTC HD2 is made to satisfy these specifications and that it was promised that HD2 will get upgrade to WM7. And just to put those specs into perspective, my Raon Everun UMPC ran Windows XP with just 6GB SSD and 600MHz CPU. Just asked Eldar if so high requirements may mean that Windows Mobile 7 is a some kind of light weight rehash of Windows XP, and he replied that it really looks so.

So will we get XP compatibility in new Windows Mobile 7 phones? Not 100% I think, but with some UI adjustments, recompiling existing XP code might be an option.

Sony VAIO Z 2010. What a disappointment?

Core i5, switchable graphics with Nvidia GT 330M, 128 GB SSD, VGA/HDMI out. Nice display and keayboard in the slick 1.4 kg package.

Congrats on removing modem and firewire. But what the heck, Sony? You still keep DVD in this “ultra-portable”? Please, its 2010, you can use this space for better battery and some port that can do 2560x1600, because frankly, this is the display resolution (with some 27-30” screen) that will be standing on the tables of prospective Z customers in the coming year.

That means, Dual DVI or Displayport. Unless that HDMI port that you put there is HDMI 1.3, huh? Anyway, Apple uses Displayport that can support 2560x1600, and others please take notice. So far, WQXGA support by PC/laptop manufacturers has a faint smell of failure, but I hope it will change in 2010.

Opera Mobile 10 Beta for Symbian

This is important. This is hilarious if you have got fast symbian phone with lots of RAM. Opera Mobile 10 is here. Installed it on my Omnia HD i8910 and immediately  tweaked RAM cache to some 50MB. Running well and not getting any “low memory” erros, like poor N97 guys. :)

It’s fast. It’s fucking Ajax compliant.

Gmail. It opened gmail in “standard view” and works fast.

Google Reader also opened in “standard ajaxy” mode. Wow.

Google Wave opened with errors. Not usable.

Youtube. Hmm, it doesn’t play youtube yet, but I have heard it from Opera some time ago, that Flash will be supported.

Friendfeed  works, as does Facebook.

What’s best for your netbook – Ubuntu, Moblin, Solaris or Windows?

During last week, expecting new Ubuntu 904 to appear shortly, I cleared the partition where my Ubuntu 810 used to reside, and played a bit with various alternatives. I installed and tried in quick succession OpenSolaris 906, Ubuntu low power MID edition, Ubuntu netbook edition, Moblin Alpha 2.

Disclaimer! This is a rant that do not in any way intend to claim to be the ultimate truth. I am only using Linux for half a year. While I feel comfortable digging through forums to enable support for various network and graphics hardware when I have free time to do this, I feel that at the moments it is not worth it. E.g. spending couple of nights to get Linux drivers working, costs me more than buying a Windows license. Having said that, I still enjoy Linux in a freaky kind of the way, treating it as a brain muscle stretching Lego for adults, and enjoying the process whenever time allows it.

OpenSolaris is interesting alternative to other Linux distributions, but not for a netbook. While I spent couple of days last year customizing Ubuntu 810 to work with all my hardware in eeepc 1000h. I do not feel like I want to spend such time again, since Ubuntu 904 supports all of it out-of-the-box. And I do not feel like I need ZFS on netbook. Its benefits are in ease of use of multi-disk storage, and all netbooks have only one disk.

Various Ubuntu derivatives – Netbook edition and lowpower MID edition. Netbook edition could be useful for touch enabled netbooks. Larger icons that make it easier to navigate with big fat fingertips. You do not need it on non-touch device. As to the the low-power MID edition - I had problems using it. It has increased fonts and icons, and after that, does not fit 1024x600. I wonder what kind of display they had in mind developing it.

Ubuntu 904. Loads quite fast (I use new ext4 file system) and supports all hardware features of eeepc 1000h. Compiz is still the best eyecandy you can get. Recommended.

Moblin – still in a hardcore alpha stage. Promising. Not recommended.

Windows 7 – RC (builds 7077 and 7100) are very stable. If you want to do any light gaming, or connect with Microsoft exchange or some other MS only corporate services,  or comfortably play 720p videos (1080p still out of question) then you have to get Windows 7.

Conclusion – for web browsing and document editing, watching movies and taking notes, ease of setup and use – Ubuntu 904 finally matches Windows. I like eye candy of Ubuntu more, but Windows still feels speedier to use. I am going to multiboot Ubuntu 904, Windows 7, and OSX on my laptop.

My new home server build on DualCore Atom

I am in that sweet time phase, when I made my research and ordered the parts. ETA is on Monday. I am building my home server on

Modecom mini ITX case with external power adaptor (96w, $70)

DualCore Intel Atom 330 in Intel D945GCLF2 (90$) – which has 1 IDE, 2 SATA connectors, Gigabit NIC

2GB RAM ($25)

500GB 2.5” laptop hard drive ($100)

and I will reuse my 1TB Barracuda 3.5” SATA from my old server.

Going for a laptop hard drive was a tough decision. I had to consider that laptop drives have limited capacity, that they are 2 more expensive than 3.5” drives, and the fact that 2*3.5 drives do not fit into mini ITX case (at least the cases that I could find in Latvia) because most of MINI-ITX cases support only one 3.5” drive and a slim CD/DVD. An alternative was to go with micro-ATX case, but then I would have to deal with the problem of finding the low-power PSU, which are not available in Latvia at all. Buying those online is possible from mini-box.com or minipc.de, but it costs an arm and a leg (upward of $100), negating any savings on purchasing a larger hard drive.

Moreover, I had to give up any idea of toying with the RAID for data protection. I will backup my personal data, which includes about 30GB of documents, photos and music, between server and my gaming pc hard drive, but for the movies, there will be no backup in this setup. I think that movies are not a critical information, because you can restore most of them from internet. At the same time, I am happy with the setup, because my space requirements will be met for another year. (I managed to fill about 700GB during 1 year). Only the small drive will be running 24x7 for torrents. It consumes less energy than larger drive and make less noise too. By the way, noise was not a consideration in this build, since I have a separate technical room for my computers. If I had to build a completely calm pc (for use on the table or in a living room) I’d had to take more expensive fanless MSI board with SSD drive, which cost too much to my taste anyway.

As for OS, I will be choosing between WHS and FreeNAS. I have seen FreeNAS, and I have yet to try WHS for the first time. And of course, there always is W7 and Ubuntu, but I do not see a benefits to running those on a headless server.

RDP/ Thanx god it’s Friday.

  

Web speeds have improved so much over last 2-3 years, that now it is so easy and convenient to RDP from work to home server, initiate download of Ubuntu 9.04 beta and even burn it to the disk that I loaded into DVD drive in the morning.

Life is good. :)

Installed Windows 7 with new taskbar on Asus Eee 1000H

Today I bought a new Ebony Black Asus Eee PC 1000H. My specs – Atom 1.6Ghz, 80GB HDD, 2GB RAM. Installed latest developer build (6801) on it. It loads during same 40 seconds but works faster than the stock Xandros.

Technorati Tags: Asus Eee PC,1000H,Windows 7,taskbar,Xandros

Going to Ukraine

I am going to spend my vacation in Ukraine, and will go there for two weeks starting from this Thursday, 19.6.

I am going by car,  route will be 2000km and will take 2 days driving in each direction. Here are 2 parts of the route.

First part is Riga - Lithuania - Poland. 845km. Plus time lost on Ukrainian border and another 140km in Ukraine to the hotel in Lutsk. I had to plan it in Google Maps. Actual navigation will be with TomTom 6.02 on Nokia N82 (Garmin XT mobile maps as backup).

2nd day will be only 900km. This one was planned in Garmin mapsource. Actual navigation will be by Garmin Mobile XT. (Nokia Maps 2.0 as backup).

There are two options for this day - going through Vinnitsa or going through Zhitomir. Both are same distance and I am trying to obtain more feedback in the excellent (russian speaking) community of autotravellers at AutoUA.

Apart from mentioned programs I still have maps of Ukraine and Ukraine largest cities in YandexMaps cache, SmartcomGPS and of course there is Google Maps mobile and MGMaps, but those require GPRS, which I will only connect when I arrived in Kherson and will buy local SIM card with unlimited GPRS.

UMPC, Scotch, Habanos

Saturday night. It is time to put gadgets aside and turn to other pleasures. Habanos, the best cigars out there. Hoyo de Monterrey Epicure No.2 and Cohiba Siglo VI. Macallan single malt scotch whisky. 10 years old. Cask strength (58.4%Vol). Last comparative shot before uncorking and lighting up. Bye.

Foxmarks for Firefox3

Firefox 3 is coming. I keep testing its builds about once a month since at least December. And the recent beta is really a mature and fast product. (Being FAST really counts when you run it on 600MHz AMD Geode UMPC as I do). The only reason keeping me from fully switching to it, was absence Foxmarks plugin compatibility with it. Not anymore. Foxmarks blog announced limited beta enrollment yesterday. I signed up. Countdown to jump over to new Firefox begins...

The all-in-one PDA will never happen

Just as I as I wrote some time ago here UMPC cannot replace my laptop yet, Shaun from Palm247 echoes my concern about viability of all-in-one device in his article The all-in-one PDA will never happen

an excerpt:

"... In reality, the physical restraints of a phone make long periods of office work almost impossible because the keyboard is too small or the screen is unable to display enough information at any one time. Many of us look at new devices and probably think “This is the one!” This could be the device that will enable me to actually work away from the office, but it never is. There are always new smartphones hitting the market that claim to let you “take your office with you” and they are not exactly lying. It is true that you can edit documents on a smartphone and that you can send and receive email, but just as I would not want to play snooker on a 2 foot x 1 foot table, I do not really want to do lots of work on my phone..."

My Worst Mobile Experience :(

Surprisingly enough, I can easily identify my worst mobile experience and unfortunately, it is same for all mobile devices that I ever worked with.

On all devices from Sony Ericsson, Nokia, HP and Raon (and actually all other laptops I used, mostly Lenovo Thinkpads) Bluetooth stack just crashes after some period of use. It takes longer on some devices, or considerably less on others, but anyway, Bluetooth inevitably crashes leading to the need to restart, reboot, sometimes even take out a battery from a frozen device.

Pocket PCs before WM5 were notorios for lack of system drivers memory, and after half a dozen of BT On/Off cycles, BT drivers would fail to load to memory.

Sony Ericsson phones would hang if phone call came during BT connection (file transmission, dialup, syncing)

Nokia handles well under load, but after several cycles of using it with Everun as dialup modem, there comes a moment when it stops connecting to UMPC, until rebooted.

Raon, just as any other XP or Vista computer, doesn't handle well going through several cycles of sleep or hibernation and guess what, at some moment when you need to get online, BT either doesn't start, or connects but doesn't load anything from the phone.

It is my biggest disappointment, that despite being a very old technology, BT stack implementation still remains buggy across various manufacturers. One day I will switch to built in HSDPA or WiMax just because of this.

Sheldon Brown, R.I.P.

Oh, my ways are strange ways and new ways and old ways,
And deep ways and steep ways and high ways and low,
I'm at home and at ease on a track that I know not,
And restless and lost on a road that I know.

Apart from being a great bicycling guru who's educating articles strongly influenced my bicycling habits, he was a great advocate of mobile lifestyle, doing many thousand miles on the road with nothing else than biped power and HP Jornada. What a man. Rest in peace, Sheldon 

Sheldon's website seems to intermittently go down under heavy traffic, but I hope that it outlives its creator. Here are some cool links to his wisdom:

Bicycle humor

Bicycling and pain

Planning Your Own European Bicycle Tour

Opera Mobile 9.5

Whoa! Opera Mobile 9.5, the successor to the 8.65 which was my browser of choice on both Nokia and Windows Mobile devices. Much more useful than any other mobile browser out there. It promises improved Ajax support and faster rendering (two features that it's got better than others already it its previous incarnation). If it delivers, then it will finally bring ability to view 99% of internet content on a smartphone screen. Yes, it will play Youtube (if you have Flash Lite 3 installed on your handset).

I will loose sleep waiting for its release (I never got so excited even when iPhone came out :) Can't wait to test it on ajax heavy gMail and gReader.

Official info ->

Oslo, Norway and Barcelona, Spain - 5 February 2008 - Opera Software, the only company that puts the Web on any device, today announced the commercial release of Opera Mobile 9.5 - the latest version of its award-winning Web browser for sophisticated feature phones and smartphones. Participants at the Mobile World Congress 2008 will be the first to experience the improved functionality of Opera Mobile 9.5.

- Intuitive user interface
- Tabbed browsing
- Improved text wrap
- Page overview, zooming and panning
- Landscape mode
- Save Web page for future offline access
- Call phone number from Web page
- Send link as SMS/MMS
- Send image as SMS/MMS
- Small Screen Rendering
- Password manager
- Web-address input auto-completion
- History and bookmarks
- Copy text
- Opera Widgets

http://www.opera.com/b2b/solutions/mobile/video

Air vs Eee

 

RegHardware pits MacBook Air vs. Asus Eee

This is one nice review, and I do share conclusions of the author. This is a fight is between an elephant (Air) and crowd of ants (you can buy 5-8 Eee's for the price of a single McAir) and I think that ants will prevail.