On 04/30/2014 04:44 PM, Scott Wood wrote: > On Wed, 2014-04-30 at 16:40 -0700, York Sun wrote: >> On 04/30/2014 03:57 PM, Scott Wood wrote: >>> On Wed, 2014-04-30 at 15:56 -0700, York Sun wrote: >>>> On 04/30/2014 03:51 PM, Scott Wood wrote: >>>>> On Wed, 2014-04-30 at 15:48 -0700, York Sun wrote: >>>>>> On 04/30/2014 03:45 PM, Scott Wood wrote: >>>>>>> On Wed, 2014-04-30 at 14:31 -0700, York Sun wrote: >>>>>>>> For powerpc SoCs (including mpc85xx, mpc86xx), global data is used for >>>>>>>> initializing LAWs, before calling function baord_inti_f(). This data >>>>>>>> should not be cleared later. >>>>>>>> >>>>>>>> Signed-off-by: York Sun <[email protected]> >>>>>>>> --- >>>>>>>> Change log >>>>>>>> v2: Instead of adding back gd init for all PPC, preserve gd for >>>>>>>> mpc85xx and mpc86xx. >>>>>>>> >>>>>>>> Note, need other maintainers to fix 83xx, 5xxx, 512x as I don't have >>>>>>>> boards to verify. >>>>>>>> >>>>>>>> common/board_f.c | 6 +++++- >>>>>>>> 1 file changed, 5 insertions(+), 1 deletion(-) >>>>>>>> >>>>>>>> diff --git a/common/board_f.c b/common/board_f.c >>>>>>>> index cbdf06f..eebb377 100644 >>>>>>>> --- a/common/board_f.c >>>>>>>> +++ b/common/board_f.c >>>>>>>> @@ -970,7 +970,11 @@ static init_fnc_t init_sequence_f[] = { >>>>>>>> >>>>>>>> void board_init_f(ulong boot_flags) >>>>>>>> { >>>>>>>> -#ifndef CONFIG_X86 >>>>>>>> + /* >>>>>>>> + * For MPC85xx, global data is initialized in >>>>>>>> cpu_init_early_f() and >>>>>>>> + * used for init_law(). gd should not be cleared in this >>>>>>>> function. >>>>>>>> + */ >>>>>>>> +#if !defined(CONFIG_X86) && !defined(CONFIG_MPC85xx) && >>>>>>>> !defined(CONFIG_MPC86xx) >>>>>>>> gd_t data; >>>>>>>> >>>>>>>> gd = &data; >>>>>>> >>>>>>> It would be better to introduce a CONFIG_SYS_EARLY_GD (or similar) >>>>>>> rather than growing a list here. >>>>>> >>>>>> That's do-able. >>>>>> >>>>>>> >>>>>>> Is there any reason why the set of targets for which zero_global_data() >>>>>>> is skipped is different from the set of targets where the gd >>>>>>> instantiation and assignment is skipped? >>>>>> >>>>>> I would think the list should be identical. But without proper testing, >>>>>> I am >>>>>> reluctant to copy the list. As you have suggested, start from 85xx first. >>>>>> Non-mpc85xx can be dealt with when they get converted. >>>>> >>>>> None of those other PPC targets currently use the generic board. They >>>>> will be tested when they are converted. >>>>> >>>> >>>> Are you suggesting to copy the list, instead of only putting those tested? >>> >>> I'm saying to use CONFIG_SYS_EARLY_GD for both things. >>> >>>> It may save other maintainer some effort of debugging. But I can't be >>>> sure they will all work. >>> >>> What good reason could there be for wanting to skip clearing of a gd >>> that was just allocated on the stack? >>> >> >> Relocating is OK. But clearing is not. At least the used LAWs variable is >> needed. There may be other variables as well. All data in gd is copied to new >> location. > > Where do you get relocating from (at this stage of boot -- of course it > will get relocated when U-Boot gets relocated)? Either gd was > initialized early, in which case we want to keep using it and not clear > it, or it wasn't, in which case we want to allocate gd on the stack and > clear it.
Exactly. gd is used before board_init_f() for many cases. > > BTW, I see x86 also skips "gd = new_gd" in board_init_r(), so I wonder > what is going on with gd on x86, and whether it makes sense to lump it > in with CONFIG_SYS_EARLY_GD. > Maybe x86 maintainers can chime in? If we define such macro, it should probably sit right above board_init_f() so it can be seen easily. There is no other place it is needed, yet. York _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
