[U-Boot] [PATCH v8 22/30] efi: sandbox: Tidy up copy_fdt() to work with sandbox

[Alexander Graf]

On 06/18/2018 04:08 PM, Simon Glass wrote:
> At present this function takes a pointer as its argument, then passes this
> to efi_allocate_pages(), which actually takes an address. It uses casts,
> which are not supported on sandbox.

I think this is the big API misunderstanding that caused our 
disagreements: efi_allocate_pages(uint64_t *memory) gets a uint64_t 
*address as input parameter, but uses the same field to actually return 
a void * pointer. This is the function that really converts between 
virtual and physical address space.

This is the explicit wording of the spec[1] page 168:

   The AllocatePages() function allocates the requested number of pages 
and returns a pointer to the base address of the page range in the 
location referenced by Memory.

So yes, we have to cast. There is no other way around it without 
completely creating a trainwreck of the API.


Alex

[1] 
http://www.uefi.org/sites/default/files/resources/UEFI%20Spec%202_7_A%20Sept%206.pdf