16
Jun
18

The Eee PC SYSLINUX bug

I ran into a weird issue with my own embedded Debian-based Linux system image on an old ASUS Eee PC netbook: the system could boot from the USB installation drive, however, it could not boot from the hard drive once the image was installed. Booting from the hard drive resulted in a blinking cursor (displayed on the second line of text), and no response to Ctrl+Alt+Del. Both drives have identical contents, as the installation drive essentially clones itself to the hard drive.

There appears to be a bug in the BIOS firmware for these devices, which corrupts the first sectors of a SATA hard drive upon attempting to boot from it. Said bug seems to only affect the SYSLINUX bootloader on a FAT/FAT32 filesystem, when not using the boot menu to select a boot device. I’ve reproduced this issue on models 1005HA and 1201T, although I have reason to believe most (if not all) models with the boot screen pictured below are affected.


Image from ADM Blog (the screen on those things is so reflective I couldn’t take a picture myself)

The only documented instance of this issue pertains to the CloudReady Chromium OS distribution (official documentation, forum post), which specifically warns Eee PC users to always boot from USB drives through the boot menu. CloudReady uses SYSLINUX for both the installer and the installed system, although according to them, only the USB installer is affected.

A workaround is to use EXTLINUX instead of SYSLINUX. EXTLINUX operates on Linux filesystems intead of FAT/FAT32. From my own testing, replacing SYSLINUX on a FAT32 partition with EXTLINUX on an ext4 partition (disabling the 64bit filesystem option as required) fixed the corruption on my model 1201T unit. I no longer have the 1005HA, where I had used another workaround which escapes me.

Advertisements
31
May
18

Mini HDMI2AV converter failure

From the video description:

My HDMI2AV converter (black version) started outputting a garbled picture all of a sudden. This might be related to an insufficient HDMI 5V supply causing permanent damage to the chips, as seen here (not my article): http://billauer.co.il/blog/2017/12/hdmi-dvi-cable-hdmi2av/

Captured with an USBTV007 “Easier CAP” device, since my AVerMedia PCI Express card could not get a signal from the broken converter.

18
Aug
15

Using a LG TV Wi-Fi adapter on a PC

Updated 2018-03-04: The latest Netgear driver still works, and has proper support for Windows 10, so I updated the link (updated 2018-04-12: now a direct link). Ignore the comments about IRQL_UNEXPECTED_VALUE blue screens, those relate to an old Belkin driver which didn’t work properly under Windows 10.

Some old LG smart TV models did not have integrated Wi-Fi, instead requiring the AN-WF100 USB Wi-Fi adapter (pictured above). Since most of the “smart” features on those TVs no longer work, re-using the Wi-Fi adapter seems like a good idea. The adapter is based on a standard Broadcom chipset, and can be used on a Windows PC with the steps below:

  1. Download the Netgear WNDA3100v2 driver.
  2. Install the driver normally. A Netgear Genie screen will ask you to plug in the adapter – close it by right-clicking its taskbar button and clicking Close.
  3. Optionally disable the “WNDA3100v2.exe” startup entry using AutoRuns to stop Netgear Genie from bothering you on every startup.
  4. Connect the LG adapter to your PC. It will be detected as an unknown “Remote Download Wireless Adapter” device.
  5. Open Device Manager, right-click the unknown “Remote Download Wireless Adapter” device, select “Update Driver…”, choose to browse for driver software, then to pick from a list of device drivers.
  6. Select the “Network adapters” category, wait for it to load, scroll down to “Netgear” and select “Netgear WNDA3100v2 N600 Wireless Dual Band USB Adapter”.
  7. Ignore the warning about driver compatibility.

After following these steps, Wi-Fi should be working. If it doesn’t, you have the wrong adapter (this guide is for the AN-WF100 only), or you’ve done something wrong.

2016-01-04_23-16-16

01
Jan
15

Notes on Red Star OS 3.0

Updated 2016-01-04: A year after Red Star 3.0 surfaced at 31C3, 32C3 held a talk on its internals. The talk documents the official root method and some malicious components present in the OS; I have updated this post accordingly.

The latest version of North Korea’s custom Linux distribution, Red Star OS – that one with the OS X style interface – has leaked onto the internet. While the individual who talked about technology in North Korea at the 31C3 conference claimed he didn’t see anybody using Red Star seriously, it’s still an interesting distribution to check out.

LLBMKWg

 

Installation

The Korean installer is quite easy to go through blind. All you need to watch out for is the network configuration, which is not set to DHCP by default. Some extras (including compilers and a LAMP stack) are available through the Customize screen.

The installer (a customized version of Fedora’s Anaconda) can run in English with a modification to the ISO: in /isolinux/isolinux.cfg, replace lang=ko with lang=en on the kernel parameters. Some minor parts of the UI remain untranslated as they are static images. The installed system will still be in Korean, but we’ll fix that later.

Red Star 3-2015-01-01-20-47-52

 

Obtaining root

The root user is disabled by default on Red Star. You can enable it with the /usr/sbin/rootsetting command, although I cannot verify how it works.

My old root-shell RPM is still available here for reference.

 

English

Like the installer, the system can run in English, and the included apps have English translations as well. Run the following commands as root, reboot, and the system will be in English:

sed -i 's/ko_KP/en_US/g' /etc/sysconfig/i18n
sed -i 's/ko_KP/en_US/g' /usr/share/config/kdeglobals

Thanks to davidiwharper on OSNews for the sed command.

Red Star 3-2015-01-02-13-50-04

 

Internet connectivity

For some reason, Red Star’s iptables firewall is set to only allow outgoing connections to certain ports. DNS is blocked as North Korea’s intranet uses IP addresses only, so you can’t get a proper internet connection on Red Star by default. To fix that, run the following command as root to clear Red Star’s default firewall rules, and reboot:

rm /etc/sysconfig/iptables

The included “Naenara Browser” is Firefox 3.5, and despite being configured to browse on the North Korean intranet, it works just fine on the internet. Its language can be changed to English by disabling the Korean language pack (thanks Chocohead): go to the second-to-last menu, select the third option, go to the fourth tab, select the “(ko-KP)” add-on, click the first button to disable it, and click the button on the yellow bar to restart the browser.

Red Star 3-2015-01-02-22-23-36

 

Dubious components

As highlighted on the 32C3 follow-up talk, Red Star contains several shady components, including but not limited to a file watermarking system service and a supposed “virus scanner”. The speakers provided instructions on how to disable these components.

 

Other notes

  • The system seems to be dated October 2012. Packages as new as 2013 are present in the system.
  • There appears to be a system file modification detector, which warns about modified system files when you log in. Running the installer in English was enough for it to complain about the kernel and initramfs images, at least for me. To disable it, run this command as root to remove its autorun entry: rm /usr/share/autostart/intcheck_kde.desktop
    • The 32C3 talk also mentions a similar service which automatically reboots the system if files related to the aforementioned malicious components are modified.
  • The disc includes a Windows executable named install.exe, which displays a dialog (actually an image lifted from the EXE resources) with two buttons. The first one displays an error, which probably tells you to boot from the installation DVD, and the second one closes the dialog.
    XP Pro-2015-01-08-20-20-29XP Pro-2015-01-08-20-20-55
  • Press Esc on the boot splash for verbose boot.
  • In several places, you’ll see English or South Korean locales replaced to accommodate the North Korean locales.
  • The English translation is surprisingly good. One theory is that all English text was taken straight out of OS X.
  • The “Crosswin” Windows compatibility layer is a wrapper around Wine 1.2.2.
15
Jun
14

I blog.

When you feel like you’re stacking up on notes-to-self on your mind, what’s the first thing you should do? Start a blog to put those on. And that’s what I did.

Apparently I created this blog in 2010, but it was more for personal matters than this, so I started over while keeping the same theme (which still looks cool) and domain.

Don’t expect regular or particularly long posts.

15
Jun
14

Linux, Intel HDA, VIA codec and headphones

Yesterday, I finally got around to setting up Debian 7 on my main system (with Intel High Definition Audio and a VIA VT1705 codec), but I ran into an issue where headphone jack detection didn’t work: audio comes out of the rear output normally, but as soon as anything is plugged into the front panel output, both outputs are disabled.

All solutions I could find relate to systems with Realtek codecs, which is not my case. Here’s what solved it on mine:

  1. Start alsamixer
  2. Scroll all the way to the right
  3. Select the “Smart 5.1” option
  4. Press . (period) to unmute it

hda_alsamixer

Despite this option being (oddly) named “Smart 5.1”, enabling it will make headphone jack detection work.




Twitter

Advertisements