Can I put Debian on my Rasberry Pi?
If you know you need hardfloat support, your best bet is to use Raspbian - which is (mostly) Debian armhf rebuilt by members of Debian for the RPi's ARMv6+VFP2 ARM variant. However, there are a lot of differences between Debian and Raspbian, for example: Raspbian wheezy includes mono from experimental (3.2.3+dfsg-5+rpi1, because wheezy's 220.127.116.11-8 doesn't work on armhf). Raspbian also updates packages that would not be updated in a Debian stable release (e.g. scratch) and, by default, includes non-free software such as Mathematica from Wolfram.
Should I buy a Rasberry Pi?
There are issues with the Raspberry Pi which means Debian does not recommend it (below). Despite the hype it is a more closed platform than many other things you could buy, and the unusual hardware can be problematic too. We suggest considering one of the many devices in the Freedombox list, or some of the other low-level development boards listed if hardware hacking is your focus
Cubieboard Allwinner A10 (Cortex A8, Mali400), $49 (most directly Pi-alike)
Olimex OLinuxIno WIFI Cortex A8, €55
EOMA68 modules (Sampling March 2013, so not in full production yet), Allwinner A10 (Cortex A8, Mali400)
Beaglebone omap3, €73, $89
OlinuxIno Mini imx233 (ARM926, i.e Debian armel), €35
If you really need the hardware-hacking aspect but not full-blown linux, and favour ARM, then these cortex M-profile based MCU boards are worth a look
Teensy Cortex M4, $19
Simplecortex Cortex M3, $45
Freescale Kinetsis K20 Cortex M3, £14
Maple Cortex M3, $35
Arduino Due Cortex M3, $50
List compiled March 2013, no doubt many more will be along soon. As you can see there are plenty of things more open, cheaper and more standard than Rasberry Pi's, and which don't misrepresent themselves.
Raspberry Pi issues
The Raspberry Pi issues relate to technical problems, software freedom and hype:
- The CPU in the Raspberry Pi implements the ARMv6 ISA (with VFP2) and is thus incompatible with the Debian armhf port baseline of ARMv7+VFP3 and ARM hardware-floating-point ports for other distributions, which all have the same baseline. It is compatible with Debian armel (armv4t, soft(emulated) FP), but floating-point tasks will be slow when running the Debian armel port.
- The Raspberry Pi boots from its GPU and only non-free software is currently available for the GPU, even starting the machine requires a large (2MB) blob of non-free, unsupportable software.
The 3D driver for the Raspberry Pi, while free software, is just a shim that passes OpenGL commands directly to the non-free software running on the GPU. This means that any issues with OpenGL cannot be fixed nor performance improved. This is better than some other GPUs because the ARM part can be rebuilt, but claims were made for this 'first Open Source ARM GPU driver' on its release, far beyond the actual functionality/openness, which offended GPU driver developers.
The Raspberry Pi has been hyped as an educational device but some would claim it is not fit for that purpose.
Binary blob needed to boot
The binary blob needed to boot the Raspberry Pi can be downloaded using the rpi-update script available from https://raw.github.com/Hexxeh/rpi-update/ . It can be used with vmdebootstrap to create a botoable SD card image, according to a recipe from Petter Reinholdtsen. No known effort to reverse engineer the blob is known 2013-10-30.