[U-Boot] [RFC PATCH 0/4] arm: zynq: implement FPGA load from SPL

[Michal Simek]

Hi,

On 20.7.2018 01:37, Luis Araneda wrote:
> Hi Michal,
> 
> On Thu, Jul 19, 2018 at 2:23 AM Michal Simek <michal.simek at xilinx.com> wrote:
>> On 18.7.2018 20:02, Luis Araneda wrote:
>>> [...]
>>> I didn't send them because just changing the defconfig isn't enough,
>>
>> It should be enough. It is configuration option and just enabling that
>> feature. You should still be able to use just u-boot.img in legacy or
>> fit format without any issue.
> 
> Ok. Should I send a patch only for the Zybo or all zynq boards? Also,
> for than one board, should I create one patch per board or only one
> big patch for all of them?

We need that functionality first but then enable it for all boards is
fine for me and via one patch.

> 
>> I think it will be good if you can look at my patch and also compare
>> boot up time when you setup compression to gzip. I expect some changes
>> in connection to this code.
>>
>>         if (IS_ENABLED(CONFIG_SPL_OS_BOOT)      &&
>>             IS_ENABLED(CONFIG_SPL_GZIP)         &&
>>             image_comp == IH_COMP_GZIP          &&
>>             type == IH_TYPE_KERNEL) {
>>
>> And I would expect that copying smaller fit with unziping bitstream will
>> be faster then what you have now. Especially on boards which bigger fpga.
> 
> I made some modifications to make gzip work, and another one dirty
> (non-upstremeable) to make external data work.
> Additionally, I added time reporting on three places. The
> modifications are attached.
> 
> I tested several bitstreams, with different compression levels:
>> gzip -c -n <comp_level> <bin_file> > <out_file>
> 
> The results, for a fit image with embedded data, are:
> file           size (bytes) time1 time2 time3
> uncompressed   2,434,112     567   597   623
> compressed -1    446,028     208  1165  1190
> compressed -4    407,764     205  1063  1088
> compressed -5    398,346     203  1094  1119
> compressed -9    376,821     200  1141  1166
> 
> The time for a fit image with external data (-E option for mkimage) is
> ~100 time units (ms?) less, and time1 remains constant at ~12 time
> units.

Can you please be more specific what time1/time2 and time3 means?

> 
> At least on my setup (Zybo Z7-20), gzip just increase the boot time.

It could be because of bitstream size is quite small for this chip.

Thanks,
Michal