[U-Boot] [PATCH] spl: fpga: Implement fpga bistream loading with fpga_load

[Marek Vasut]

On 07/18/2018 04:00 PM, Michal Simek wrote:
> On 18.7.2018 14:54, Marek Vasut wrote:
>> On 07/18/2018 02:51 PM, Michal Simek wrote:
>>> There shouldn't be a need to call private spl_load_fpga_image()
>>> because the whole sequence should be already handled by fpga_load().
>>> The patch let spl_load_fit_image() to load data to right location based
>>> on "load" property in FIT and then call fpga_load().
>>
>> NAK
>>
>> This breaks Arria10, sorry. The private loading function is needed on
>> Arria10 as the whole bitstream is not available in RAM and needs to be
>> loaded piece by piece, see [1]
>>
>> [1]
>> http://git.denx.de/?p=u-boot/u-boot-socfpga.git;a=blobdiff;f=arch/arm/mach-socfpga/spl.c;h=82adb5dfb8de62e3d928f6f4405705f3f32a780c;hp=7ee988a2d59831ec6bff927b2a5fdad7f57da055;hb=21f835ebf2b40fc8a3e8b818c5c5ba2555dd7c65;hpb=bd198801cb95b5a8460c95a762cc4a9a44ca85ef
> 
> We are discussing this over IRC and it is clear that current solution
> for altera A10 is one ugly hack which is just going over current flow.
> Load address from ITS is ignored, the same for hashes.

The load address must be ignored because it's used to load fitImage
piece by piece. There is nowhere to load the whole FPGA bitstream.

> With small changes compression could be also possible to use without big
> problem which should very beneficial to speedup load from slower memories.
> 
> What we are missing is do fit image reading by chunks to feed fpga.
> 
> Currently spl_load_fpga_image() is dummy function which none is calling
> that's why the first solution could be to simply revert this patch
> because there is no functionality behind.

See the link above, I am just holding back on pushing this mainline
because it's gonna be superseded by the firmware loader once it's
finished. Until then, this is needed for A10.

> The second solution is to check if load address is not 0 and call
> fpga_load only for that. In this case there is a need to check size for SPL.

0 is a valid load address, so no.

-- 
Best regards,
Marek Vasut