[U-Boot] u-boot FIT image support

[Simon Glass]

Hi York,

On 7 August 2015 at 17:12, York Sun <yorksun at freescale.com> wrote:
>
>
> On 08/07/2015 03:47 PM, Simon Glass wrote:
>> Hi York,
>>
>> On 7 August 2015 at 14:48, York Sun <yorksun at freescale.com> wrote:
>>>
>>> Simon,
>>>
>>> I was doing an experiment to put the load address and entry address of Linux to
>>> higher than 32-bit address. I found it is broken to process more than 32-bit
>>> addresses. When I attempted to fix it, I was troubled by those code used for
>>> both host and target, like common/image-fit.c. For example, to process 64-bit
>>> address, the function
>>>
>>> int fit_image_get_load(const void *fit, int noffset, ulong *load)
>>>
>>> should be converted to
>>>
>>> int fit_image_get_load(const void *fit, int noffset, uint64_t *load)
>>>
>>> ulong is 64-bit for 64-bit target such as ARMv8, but it can be 32-bit on host.
>>> If I use uint64_t, all related code in bootm and others need to change. Before I
>>> go too far, I'd like to check if anyone has tried to enable this in FIT image.
>>>
>>> #address-cells = <2>;
>>>
>>> I can try to use uint64_t in place of ulong for all related code if that's
>>> right. That will be a lot of change.
>>
>> Perhaps I misunderstand something, but I think ulong should be OK on
>> the host. I just needs to hold a machine address. On a 32-bit host
>> this cannot be 64-bit. Can you explain the problem a bit more?
>>
>> I have not need #address-cells in a FIT.
>>
>> It would be better to use ulong for addresses in U-Boot I think. It is
>> safe and efficient on both 32- and 64-bit machines.
>>
>
> Simon,
>
> Considering this situation, building FIT image on an ubuntu 12.04 32-bit host,
> for ARMv8 target. I believe ulong is OK on 64-bit target. But it is not for the
> host mkimage. To proper deal with address cell = 2, the function
> fit_image_get_load() and fit_image_get_entry() need to make 64-bit address from
> FIT image. mkimage runs on 32-bit host doesn't take ulong as 64-bit, does it? So
> I can generate a FIT image with the address cell and load/entry address I need,
> but I cannot display it correctly with mkimage. I think I can use the image on
> 64-bit target after fixing some parsing code as I mentioned.
>
> The background for this experiment is I am trying to shift DDR to a continuous
> space. For ARMv8, DDR can have three regions, with only 2GB under 32-bit address
> space.

We really don't want to end up with everything being 64-bit just
because the tools need to work correctly. I wonder if phys_addr_t
might help here? We could define that to be 64-bit for the host,
perhaps?

Regards,
Simon