On Mon, Sep 12, 2022 at 11:22:53AM +0200, Wolfgang Denk wrote: > Dear Ovidiu, > > In message <[email protected]> you wrote: > > The XTRN_DECLARE_GLOBAL_DATA_PTR declarations in ppc code are permanently > > commented out, so there are no users for this macro: > > #if 1 > > #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r2") > > #else > > #define XTRN_DECLARE_GLOBAL_DATA_PTR extern > > #define DECLARE_GLOBAL_DATA_PTR XTRN_DECLARE_GLOBAL_DATA_PTR \ > > gd_t *gd > > #endif > > > > Remove all references. > > Actually the commented out code contained some information, and I > feel it would be a pity if that got lost: > > > -#if 1 > > #define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r2") > > -#else /* We could use plain global data, but the resulting code is bigger > > */ > > -#define XTRN_DECLARE_GLOBAL_DATA_PTR extern > > -#define DECLARE_GLOBAL_DATA_PTR XTRN_DECLARE_GLOBAL_DATA_PTR \ > > - gd_t *gd > > -#endif > > Maybe we can keep the information that using global data for the GD > pointer would be possible too (and simpler, as it does not require > the reservation of a specific register for it), but that the > implementation uses a register nevertheless because this results in > smaller code? > > Maybe add such a comment instead ? >
This is slightly mentioned in doc/develop/global_data.rst currently, but a follow-up to expand on this would be good. -- Tom
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