Dear Albert ARIBAUD, On 11 January 2011 02:21, Albert ARIBAUD <albert.arib...@free.fr> wrote: > Le 10/01/2011 15:04, Minkyu Kang a écrit : > >>>> How about lcd_setmem function? >>>> panel_info is located at bss area, but lcd_setmem access this structure. >>>> Is it illegal? >>> >>> This must not be done before relocation. >> >> No, please see 360 line of arch/arm/lib/board.c >> This function is called before relocation. > > Then it cannot access panel_info, which is "not there yet" at the time > lcd_setmem() executes.
No, access for reserve the memory for LCD and we got wrong values. Did you test about it? > > You must either move the call to lcd_setmem() to after relocation, or find a > way not to depend on BSS. This problem is not belong to my code. Move after relocation? it's easy. but, how we can reserve the memory for LCD? > >> And how about init_func_i2c()? >> This function is called twice, before the relocation and after relocation. >> When we use board_i2c_init function then, there is possibility that >> use symbols in bss because of this function is called after >> relocation. > > If it is used both before and after relocation, then it has to respect the > strictest case, which is before relocation, and not access BSS. > >> If we ignore this exception, it will be a big constraint. >> >> btw, there are any side effects on my patch? >> I think.. It is just a little safety feature. > > Regardless of the patch, if your code writes to panel_info or any other BSS > variable before relocation it will trash the relocation tables that exist at > BSS location at this point. > > IOW, accessing BSS before relocation is forbidden, not just out of fancy, > but for a serious reason. This patch is not for accessing BSS before relocation, it's for prevent exceptions. Thanks Minkyu Kang -- from. prom. www.promsoft.net _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
