[U-Boot] SUNXI: A64: Increase SPL size

[Jagan Teki]

Hi Andre,

On Thu, Nov 9, 2017 at 5:48 PM, Andre Przywara <andre.przywara at arm.com> wrote:
> Hi,
>
> On 09/11/17 12:11, Maxime Ripard wrote:
>> On Thu, Nov 09, 2017 at 01:29:21AM +0530, Jagan Teki wrote:
>>> Hi,
>>>
>>> I'm trying to increase SPL size to 64K(with SRAM A2), so-that SPL can
>>> able to fit new features like falcon. I knew the limit about 32K but
>>> page[1] stating that we can use approximately 192 KiB of contiguous
>>> SRAM.
>>>
>>> eGON.BT0 has limit of reading 32KB, Can't we use > 32KB SPL here?
>>> because I've tried with 64K SPL size with existing SPL code and was
>>> able to boot, but with increasing SPL by enabling falcon seems like
>>> BROM unable read eGON.BT0 which eventually booting failed. Any inputs?
>>
>> I've been able to use the falcon mode without this change on an A33,
>> what's so different about the A64?
>
> That the SPL is bigger in AArch64 and enabling SPL_OS_BOOT will probably
> exceed 32KB (we are quite close already)
>
> Jagan: you could try this branch of mine [1], this enables a 32-bit SPL,
> which is smaller than the AArch64 version.
> You might be able to include Falcon there, but I am afraid you have to
> work out how to boot a 64-bit kernel from there and how to enable SMP.
>
> Hence my question about the pain you want to endure and if those 500ms
> are really worth it.
>
> Cheers,
> Andre
>
> [1] https://github.com/apritzel/u-boot/commits/a64-fel32-wip

Looking at the "32-bit SPL" patch [2], commit message "so a 32-bit SPL
can be combined with a 64-bit U-Boot" Does this means we need to build
U-Boot proper for 64-bit compiler with pine64_plus_defconfig and SPL
for 32-bit compiler with sun50i_spl32_defconfig? because I've tried of
sun50i_spl32 with 32-bit compiler ended with build issue.

Build log:
----------
  MKIMAGE u-boot.img
  BINMAN  u-boot-sunxi-with-spl.bin
binman: Device tree 'u-boot.dtb' does not have a 'binman' node
Makefile:1157: recipe for target 'u-boot-sunxi-with-spl.bin' failed
make: *** [u-boot-sunxi-with-spl.bin] Error 1

Look like it is not taking CONFIG_SPL_FIT_GENERATOR script.

[2] https://github.com/apritzel/u-boot/commit/5f1fe133aabfd0c3c5867c453cb405d9624e52ce

thanks!
-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.