Month: April 2006


I would expect that the PIN digits have a quite good random distribution. Although impractical at the ATM point a smartened brute force attack could effectively work provided you have some machinery at home.Assuming that the distribution of the dirt per finger (or the distribution of cleaning factor per finger) is flat then the ATM pad at the gasoline station where I usually refuel my car provides some odd evidences.
The numeric pad has some keys clearly cleaner than others – ‘7’ and the square ‘5’, ‘6’, ‘2’ and ‘3’ are much more clean than the rest.
The site of the days is also the application of the day: GNU Talk Filters. Moreover cleans up the mistery about how Zom3 PE0pl3 sUCc33dZ pErZYZt3N7lY IN wRYT!n6 l1cE Th!S.

Adventure in cross compiling land

If you have a C background you may find correct and appropriate that filenames are case sensitive. After all ‘a’ is different from ‘A’ as much as 65 is different from 97. If you have a BASIC background you may equally find correct and appropriate that filenames are case insensitive. It doesn’t matter how you write it, it is always the same character.
Every approach has its strengths and good arguments. The problem arise when one of the parties blindly ignores the rest of the world.
Well this may sounds like gibberish until you try to compile the linux kernel on windows. In this impressive set of source there are a bunch of files in the same directory that have the same name case-insensitive-wise. Moreover, if you untar the sources you get no warning sign since the tar command silently overwrites existing files. You get some hint of the problem when you copy sources with the windows GUI from a samba share to you local disk.
The problem is not so hard indeed, but if you don’t want to tamper source file structure it is better to rely on a case sensitive filesystem. That means that you cannot use Windows.
So I switched to Linux. After all FreeScale gives you the ready made cross compiler for Linux, so it is a clear sign of the way to go.
At workplace I installed the recently released Fedora Core 5. (Yes, I just completed a satisfactory configuration of the FC4 on my laptop 🙁 ). I must admit that Fedora Core, at last, has an original look. And a good look. Apparently they stopped following Redmond and Cupertino and started to set their own trend. Well done, I like it.
On the other hand having FC5 seamlessly working in a Windows environment is not something for the faint hearted. Be prepare to a good amount of swearing before you can resolve names, browse windows shares and access files there contained. Once done it works very well.
Back to Linux kernel compilation. Despite of what you may think by a look at my desk, I like cleanness and order, at least in files. So I want to store in the versioning system nothing that can be derived, just primary sources. With Kernel source this is a little fuzzy. In fact you download sources that are ‘distclean’ed. I.e. no kernel configuration is set. First you configure the kernel either by issuing one of ‘make menuconfig’, ‘make oldconfig’, ‘make xconfig’ or by picking up one of the precanned configuration by typing something like ‘make xyz_config’.
Anyone of these performs some operations – a file ‘.config’ is placed in the kernel source root, some symlinks and some files are created. So far so good. A file named ‘autoconf.h’ is required in order to build the kernel. This file is just the C version of the ‘.config’ file. In other words and simplifying a bit, in ‘.config’ you find something like ‘VALUE=y’ and in ‘autoconf.h’ you find ‘#define VALUE 1’.
Now I would expect that ‘autoconf.h’ is created from ‘.config’ somewhere in the Makefile. This is not true. The only way to create ‘autoconf.h’ (I found so far) is to interact with the system using one of the ‘make *config’. This is bad to me, since it prevents a fully automatic build.
On the other hand it is true that the configuration changes quite seldom, so you don’t have to ‘make distclean’ a lot and the ‘.config’ file you generate will be with you for long.
Maybe I didn’t search enough, but I have to do some actual work and produce some results beside googling for answers trying to bend universe to my personal view.