Dear Matthias Kaehlcke, In message <20091208151358.gd31...@darwin> you wrote: > > i am starting to look at this issue and it seems i need some more guidance: > > before relocating U-Boot to RAM for ARM920T processors a jump to the > label *lowlevel_init* is performed, where RAM timings are supposed to > be set up. in the patch i sent these operations are performed in > assembly and you asked me to rewrite them in C. > > i'm relativly new to low-level setup, so i apologize if the following > question sounds plain stupid to you: is C really available at this > point? if my interpretation of the code in cpu/arm920t/start.S is > correct, C code starts at start_armboot, after relocation of > U-Boot. and after that point i'd think it's to late to change RAM > timings as U-Boot is running from RAM.
After relocation we have a full-blown, "normal" C runtime environment. Before that, you can use C as well, if you mind the restrictions (like data and bss not being available/writable yet, no real stack, etc.). > could you please give some advice to clear my confusion and maybe > provide a pointer to a board/cpu which handles low-level setup in > the intended way? If you check theinit code in cpu/arm920t/start.S you will notice that one of the really early things it does is calling coloured_LED_init() and red_LED_on(). Note that these functions are implemented in C. What can be done here, should also be possible in your case. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de Commitment, n.: Commitment can be illustrated by a breakfast of ham and eggs. The chicken was involved, the pig was committed. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot