These days, quite a few devices already come with built-in iPXE support: Some hypervisors (qemu, Proxmox, VMWare, VirtulBox, etc.) support iPXE right out of the gate but there’s also an increasing number of network equipment vendors that sell network interface cards with bundled iPXE support. But what if the bundled iPXE firmware is out of date and/or lacking a relevant… Read more »
These days mainboards usually come with some sort of wizbang tool that allow the user to update the BIOS from a USB drive or straight via network. Except, of course, that one single mainboard that absolutely needs a new BIOS version on a late Friday afternoon. And obviously the manufacturer only provides a flash tool for DOS and the mainboard… Read more »
Link aggregation is a method of bundling interfaces together to act as one for increased bandwith and/or failover. One of most used protocols, next to a couple of proprietary ones, for controlling such a channel bond is LACP, the Link Aggregation Control Protocol. 1. Configuring LACP on Dell S4810 Let’s assume, we want to bond two 10G Ethernet ports together,… Read more »
Unfortunately, Atmel does not ship a hex file for their STK500 development system that could be used to update the firmware using 3rd party tools like avrdude. Instead, an encrypted ebn-file comes with the latest Atmel Studio. The tools that is used to flash the firmware onto the ATmega8535 is a bit dull, though. Preparing serial connection First, hook up… Read more »
As I wrote in an earlier post, the ambient light button on HP EliteBooks is per default mapped to switch off the touch pad. Since it’s placed right next to the function keys that increase or decrease the screen brightness, it happens quite often that the key is hit by accident. If you’re running KDE, hitting Fn+F11 not only switches… Read more »
To enable the ambient light sensor on an HP EliteBook 8440p or 8460p run To disable:
The button that is supposed to toggle the ambient light sensor on HP EliteBooks 8440p and 8460p per default switches off the touch pad. That is because Fn+F11 (scancode 0x33), which is the ambient light button, is incorrectly mapped to KEY_TOUCHPAD_OFF (keycode 193) in kernel. To remap the scancode to another keycode, you can use setkeycodes. An appropriate choice for… Read more »
If you plug the PL2303 USB to serial adapter (or any other FTDI-like USB adapter) into your USB port, udev creates a /dev/ttyUSBX device with limited read and write permissions (0660 per default). Usually, only the root user and a specific group can access the device at all . To access the device as a regular user, you can either… Read more »
There are quite a few bug reports on the kde bug tracking system about kde losing display settings on logout (e.g. Bug 183143). But since this problem has been present for a couple of years and is still existing in the latest version of KDE (i.e. 4.8.5 at this writing), here’s a workaround: Add a parameter called StartupCommands to the… Read more »
To update the initrd.img to load additional drivers early in the boot process, normally you would simply run /sbin/mkinitrd and let the script do the work. But what if the initrd.img used during the installation of CentOS lacks an important driver? Maybe you want to netboot CentOS, but the initial ramdisk CentOS provides doesn’t have the right modules for you… Read more »