On 06/19/2012 03:16 PM, Jesper K. Pedersen wrote: > On Sun, 17 Jun 2012 16:43:02 +0200 > "Jesper K. Pedersen"<li...@famped.dk> wrote: > >> I am at my wits end getting the twothreads example working on my >> Olimex P256 board (AT91SAM7S256 based). >> >> Calling the cyg_mutex_init does not return. Also I notice that the >> call to the printf line before the call to cyg_mutex_init prints >> extremely slow on my terminal. >> >> I have set the default console up to tty0 going to ser0. This part >> works fine with my other software running on the board (normal >> expected transmission speed). >> >> Are there any "gotcha'" involving threading on the AT91 series >> microcontrollers? >> > Problem was solved. > > For some reason if you put any output function (printf's) in the > cyg_user_start the threading will hang. > > Removing all output will allow for threading and the example works as > expected. > > I wonder if this is intended or if its a bug in the A91SAM7 eCos. > > Best regards > JesperKP > I have lots of diag_printf's in my cyg_user_start() running on an AT91 ARM7 and a ARM9. Maybe because you use printf? Be carefull: Code running in initialization context runs with interrupts disabled and the scheduler locked. Only after cyg_user_start, the scheduler starts and resumes all threads. Maybe (if I remember well; search the list for the diff between both printfs) printf uses interrupts (to know when the hardware has sent a byte), and diag_printf doesn't.
You must also realize that printf's can take a lot of CPU. And no, it is certainly not intended or a bug in the ecos CVS code (although I don't know the twothreads test): it is your bug ;-) . Success, Jürgen -- Jürgen Lambrecht R&D Associate Tel: +32 (0)51 303045 Fax: +32 (0)51 310670 http://www.televic-rail.com Televic Rail NV - Leo Bekaertlaan 1 - 8870 Izegem - Belgium Company number 0825.539.581 - RPR Kortrijk -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
