I just set up a GCC toolchain for my STM32 E407 board in Ubuntu 12.04 (32bit). Here is how I did it: http://nyatekniken.blogspot.se/2012/09/building-gcc-tool-chain-for-stm32f4.html (http://nyatekniken.blogspot.se/2012/09/building-gcc-tool-chain-for-stm32f4.html)
Hi,
Those interested in a Windows toolchain can download ChibiStudio here: http://sourceforge.net/projects/chibios/files/ChibiStudio/
The toolchain includes everything required and many demos for most Olimex's STM32 boards, just unzip it under C:/ and it is ready.
Giovanni