Paul Legato » unix

Dell PowerEdge BIOS Upgrade on Linux

Paul Legato — Sat, 31 Jul 2010 05:13:59 +0000

Dell only provides certain PowerEdge BIOS flash upgrades in the form of Windows-only self-extracting archives (despite the facts that they claim to officially support Linux and that the BIOS flash utility itself is a DOS program.) Ordinary unzip won’t open the self-extracting archive. You need to run it on a Windows system, which I don’t have. Here’s how to flash your PowerEdge BIOS without Windows.

Dell provides the biosdisk utility to make a bootable FreeDOS image with the BIOS upgrade executable on it, but it doesn’t work with the Windows-only PowerEdge 4400 BIOS upgrade, since that won’t run on FreeDOS. They claim that biosdisk isn’t intended for PowerEdge systems, since they all have Linux BIOS flashes available; this does not seem to actually be the case for the 4400.

The Windows self-extractor does run under WINE, but it demands an actual floppy drive device to write to, which my computer doesn’t have. WINE also doesn’t seem to support mounting an image file as a floppy device, for some reason. You’ll need to use something like VMWare or a computer with a physical floppy drive to get this to extract itself.

Once you have a floppy image, here’s how to flash without biosdisk or Windows available:

Use WINE to extract the archive. For maximum fun, the upgrade I have refuses to just extract itself; instead, it requires that it has access to a floppy drive to write to directly. Sigh. Ok. Working on that. Updates to come. winecfg
Install syslinux. (apt-get install syslinux). We are going to use memdisk, a boot loader that creates a RAM drive and then loads an operating system, to load FreeDOS.
Get a FreeDOS boot disk image and add your flashing .exe to it.Mount with something like mount -t vfat /path/to/freedos.img /mnt -o loop, then just cp your flashing .exe to /mnt. (If you got a gzipped image, gunzip it first.
Edit /etc/grub.d/40_custom to add a boot menu entry for memdisk/FreeDOS.
```
menuentry "FreeDOS" {
    set root=(hd0,2) #### <--- Change this to your /boot partition!
    linux16 /memdisk floppy
    initrd16 /freedos.img
}
```
As noted, change the root entry to point to your actual /boot partition, so GRUB can find the images. Also note that the partition normally mounted at /boot will be mounted as the root directory (/) at boot time, so it’s not necessary to prefix /boot before the image file names.

Then, reboot and select FreeDos from the GRUB menu. Run your DOS-based flash program, and all is well.

Flash BIOS Without a Floppy

Paul Legato — Sun, 09 May 2010 00:09:53 +0000

Flashing the BIOS without a floppy drive can be done with an Ultimate Boot CD (free!) and a USB memory stick. BIOS upgrades usually come in the form of an MS-DOS executable meant to be run from a bootable floppy, but modern computers don’t usually have floppy drives anymore, and who has a copy of DOS lying around anyway?

Download a copy of the free Ultimate Boot CD and burn it to disk. FreeDOS (and a lot of other useful stuff) is preinstalled on the CD. As the name implies, FreeDOS is a free, open source, binary-compatible replacement for MS-DOS.
Download the replacement BIOS from your motherboard’s manufacturer. Unpack it onto a USB flash drive.
Plug your flash drive into the target computer and boot it with your Ultimate Boot CD. Select FreeDOS from the menu.
FreeDOS asks a number of configuration questions while booting. You can usually leave all at their default except for the ASPIUSB driver. ASPIUSB is not enabled by default (at the time of this writing), but is necessary for the use of a USB flash drive under DOS, so enable it when prompted.
If you miss the prompt for the USB driver, don’t worry. Type “menu” at a command prompt and enable USB devices from the popup menu.
Change to your flash drive by typing e.g. R: and execute the BIOS flash utility as per the manufacturer’s instructions. (If you don’t know which drive letter to use, type “menu” and select the option to display active drive letters.)

Libcurl bindings for Java on Macintosh

Paul Legato — Sun, 14 Mar 2010 03:35:14 +0000

Libcurl’s Java bindings now compile on Macintosh, with a few minor modifications to the Makefile. Get the code from my Github account.

Update: More recent Java bindings, which do not seem to be linked anywhere on the libcurl site, are available at http://www.gknw.net/viewvc/trunk/?root=curl-java. Still no multi support, though.

Launchctl vs Cron: You’ve Got To Be Kidding Me

Paul Legato — Mon, 01 Feb 2010 23:05:30 +0000

So I wanted to write a cron job on my Mac. Just run this script every day at midnight. Nothing fancy.

In standard Unix, this is one line in a crontab:

0 0 * * * /some/script

That’s it. Put that in your crontab and /some/script will run every day at midnight.

Naturally, I typed man crontab on my Mac to get started. Apple likes to make weird minor modifications to standard Unix commands sometimes. I found:

(Darwin note: Although cron(8) and crontab(5) are officially supported under Darwin, their functionality has been absorbed into launchd(8), which provides a more flexible way of automatically executing commands. See launchctl(1) for more information.)

More flexible, huh? I’m all about more flexible! Sounds good. Another well thought out Apple improvement, sweeping away 30+ years of Unix cruft at a stroke!

Not quite. Turns out that you must submit jobs to launchctl as XML files. We all know how much I hate XML files, and this is a great example of why. That one line cronjob becomes this fragile ~20 line XML monstrosity:

Label net.sourceforge.awstats.update-daily LowPriorityIO OnDemand Program /opt/local/www/awstats/cgi-bin/awstats.pl ProgramArguments -config=INSERT_YOUR_COMPUTER_NAME_HERE.local -update ServiceDescription Updates statistics for awstats.pl every day at 3AM. StartCalendarInterval Hour 3

But it defines its own syntax!! I can already hear the XML cheerleaders say. Well, sort of. You can read it, kinda, even if you are unfamiliar with the syntax, but you certainly can’t write it without spending half an hour or more reading about and then absorbing the syntax documentation first. For comparison, you can learn the syntax of a crontab entry in around 1 minute. Hell, the documentation of the crontab syntax is shorter than that one simple launchd plist example, nevermind the 13 page manpage explaining the launchd plist syntax.

More verbosity means more things that can be screwed up, as that discussion thread amply demonstrates. Even extremely simple jobs become ordeals. In this case, the problem stems from trying to do too much in one tool, forgetting the Unix philosophy: do one thing, and do it well. Create reusable, chainable tools, rather than one monolithic beast that tries to do everything. Apple bills launchd as a replacement for init, rc, init.d, rc.d, SystemStarter, inetd/xinetd, atd, crond, and watchdogd. Maybe others, too.

Developing a language powerful enough to capture the functionality of all of those different tools results in a massively complex, fragile, general-purpose language. Developing a tool that does exactly 1 of those things results in a tiny, simple, clean, resilient language that is easy to use and hard to screw up. Complex cases are then handled by gluing those many small tools together, not by programming a massive monolith.

Fortunately, cron is still supported by Mac OS X as a legacy service, so I’m using that. If and when they finally remove it from the OS altogether, I’ll be using the MacPorts version.