ChibiOS Free Embedded RTOS

mbed seems to be Arduino for the smart ones. The Web IDE is feature-rich (it even includes Mercurial!), and as you said, the library is also quite rich. There are some irritating limitations on that platform, though. For instance, you can't use your own compiler. Yes, you have no need to, but if you ...

Aha, I see. So I'll wait for it. Thank you again for your kind replies.

Is chrtclib ported to 3.0 yet? I get compiler errors at it.

Okay, I see. Thank you very much for the explanation.

Yes, they are at the same priority. But why is it working when I add the sleep function?

Well, AFAICS, it's definitely not a stack overflow. The thread for 2.x just locks everything by doing nothing in a cycle, when the thread for 3.x does something and doesn't lock anything. That's how I see it from my point of view. Also, how could that be a stack overflow if when I added a sleep ...

Also, are there any problems if I don't want to use LTO? What exactly will not be fine if I don't use it?

I have a not-so-obvious comment regarding threads in ChibiOS/RT 3.x.
In 2.x, a thread like this will work just fine:

static WORKING_AREA(waBtnThread, 128);
static msg_t BtnThread(void *arg) {
(void) arg;
chRegSetThreadName("btn");
while (TRUE) {
while (!palReadPad(GPIOB, GPIOB_BTN1)) {
// Here ...

Got the same problem with segfault, I use Launchpad's arm-none-eabi-gcc:
[03:27:45] che@quad:~/mcu/chibios-stm32f103/ChibiOS-RT/demos/STM32/RT-STM32F103-OLIMEX_STM32_P103$ make
Linking build/ch.elf
main.c: In function 'main':
main.c:41:5: internal compiler error: Segmentation fault
int main(void ...

What's the most common and convenient way of using two or more SPI devices on a single SPI bus? The point is that I can use the same MISO/MOSI/SCK pins, and the only thing that really differs is the CS (ChibSelect) pin.
I see only one: reconfigure SPI (spiStart) with the appropriate ChipSelect pin ...