[PATCH 2/6] Add shared update_fdt() function for ARM/ARM64

[Mark Salter]

On Thu, 2013-10-03 at 15:27 +0100, Matt Fleming wrote:
> On Thu, 03 Oct, at 09:43:24AM, Mark Salter wrote:
> > On Thu, 2013-10-03 at 10:52 +0100, Matt Fleming wrote:
> > > > +#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
> > > > +static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
> > > > +                            void *fdt, int new_fdt_size, char *cmdline_ptr,
> > > > +                            u64 initrd_addr, u64 initrd_size,
> > > > +                            efi_memory_desc_t *memory_map,
> > > > +                            unsigned long map_size, unsigned long desc_size,
> > > > +                            u32 desc_ver)
> > > 
> > > Hmm... does this function really belong in efi-stub-helper.c? That file
> > > should be for architecture independent functionality only.
> > > 
> > 
> > It isn't really arm-specific although arm is the only user right now.
> > We're using the FDT to pass EFI boot info that is passed in the boot
> > params block on x86. So potentially other architectures could use the
> > same code.
> 
> It's not EFI-specific either, apart from the fdt property names.

Not EFI-specific in the sense that it uses the EFI services, but it is
EFI-specific in its function.

> 
> > How about making it someting like:
> > 
> > #ifdef ARCH_NEEDS_EFI_FDT
> > static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt,
> > ...
> > #endif
> > 
> > so the architecture can decide whether to include it or not.
> 
> Is one implementation of this function going to fit all architectures?
> Can we be sure of that ahead of time?
> 
> I'd prefer this to be kept in arch/ for now, and possibly moved into
> efi-stub-helper.c at a later date if indeed it turns out to be generally
> useful.

Fair enough. I don't have a strong opinion about it either way. Just a
natural instinct to share the code if possible, but it is easy enough
to change later if others want to use it.

--Mark