Dear Albert Aribaud, Am 03.07.2011 um 08:56 schrieb Albert ARIBAUD:
> Hi Aneesh, > > Le 03/07/2011 06:47, Aneesh V a écrit : >> Hi Albert, >> >> On Saturday 02 July 2011 01:21 AM, Albert ARIBAUD wrote: >>> Hi Aneesh, >>> <snip> >> I was thinking of doing that in start.S itself. I haven't looked at >> all the details though. >> >> BTW, please note that I am not trying to support disjoint BSS in >> regular u-boot. I think it becomes complex with relocation + it doesn't >> seem to be worth when all SDRAM is at our disposal. >> >> So: >> 1. #ifdef CONFIG_PRELOADER part in start.s will just pass __bss_start >> and __bss_end to the clear_bss function(assumes no relocation). >> 2. #else part of above will assume that bss follows text and data(or at >> least that __bss_start > _start), so add relocation offset to >> __bss_start and __bss_end, and pass them to the clear_bss() >> >> Does that sound ok? > > (note clear_bss is not a function in arch/arm/cpu/armv7/start.S, it is only a > label) > > So, considering what is already in arch/arm/cpu/armv7/start.S, you would just > add a conditional variant to the BSS clearing code for the preloader case? > > If so, and considering that you'll pass an offset of 0, why would you need > that variant for? With offset=0, the code already does what you want, does it > not? we are looking forward to have relocate_code(), clear_bss(), a.s.o. implemented in c in future (as I understood the discussion around christmas about relocation). Wouldn't it be nice to implement now a SPL version of clear_bss(int start, int size) in c and skip the relocate_code() stuff in start.S completely? As I see the normal way to boot is: -> some start vector -> lowlevel_init -> board_init_f -> relocate_code -> board_init_r for SPL we do not need the steps after board_init_f. board_init_f for SPL should implement the generic way to load data from predefined (compile time) source to predefined target address and branch it. Therefore a simple memset() in board_init_f could be sufficient to clear the bss. regards Andreas Bießmann _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot