[U-Boot] [PATCH 2/3] common: Implement support for linker-generated arrays

[Marek Vasut <marex@denx.de>]

Dear Joe Hershberger,

[...]

> > +#define ll_entry_declare(_type, _name, _section_u, _section_d)         \
> > +       _type _u_boot_list_##_section_u##_##_name __attribute__((       \
> > +                       unused, aligned(4),                             \
> > +                       section(".u_boot_list."#_section_d"."#_name))); \
> > +       _type _u_boot_list_##_section_u##_##_name
> 
> Why repeat the "_type _u_boot_list_##_section_u##_##_name" instead of
> just leaving the semicolon off after the __attribute__()?

Good idea. Do you like my documentation fairytail btw ? :p

> > +
> > +/**
> > + * ll_entry_start() - Point to first entry of linker-generated array
> > + * _type:      Data type of the entry
> > + * _section_u: Subsection of u_boot_list in which this entry is placed
> > + *             (with underscores instead of dots)
> > + *
> > + * This function returns (_type *) pointer to the very first entry of a
> > + * linker-generated array placed into subsection of .u_boot_list section
> > + * specified by _section_u argument.
> > + *
> > + * Example of usage:
> > + *
> > + * struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub);
> > + */
> > +#define ll_entry_start(_type, _section_u)                              \
> > +       ({                                                              \
> > +               extern _type _u_boot_list_##_section_u##__start;        \
> > +               _type *_ll_result = &_u_boot_list_##_section_u##__start;\
> > +               _ll_result;                                             \
> > +       })
> 
> Tricky.  I didn't realize this gcc extension existed.

All this is a horrible pile of tricks

[...]