[U-Boot] [PATCH v2 2/3] spl: add relocation support【请注意，邮件由sjg at google.com代发】

[Andy Yan]

Hi Simon:

On 2019/5/23 上午3:39, Simon Glass wrote:
> Hi Andy,
>
> On Tue, 21 May 2019 at 19:43, Andy Yan <andyshrk at gmail.com> wrote:
>> Hi Andre:
>>
>> Andre Przywara <andre.przywara at arm.com> 于2019年5月20日周一 下午11:59写道：
>>
>>> On Mon, 20 May 2019 14:34:01 +0800
>>> Andy Yan <andy.yan at rock-chips.com> wrote:
>>>
>>> Hi,
>>>
>>>> On 2019/5/19 上午12:26, Simon Glass wrote:
>>>>> Hi Andy,
>>>>>
>>>>> Instead of this could you:
>>>>>
>>>>> - move ATF?
>>>> All rockchip based arm64 ATF run from the start 64KB of dram as this
>>>> will give convenient for kernel manage the memory.
>>> This is just BL31 of ATF, right?
>>> ATF recently gained PIE support for BL31 [1], so by just enabling this in
>>> platform.mk you will get a relocatable BL31 image, with a very minimal
>>> runtime linker. Worked out of the box on Allwinner for me, but YMMV.
>>> So you could load newer ATF builds everywhere.
>>>
>>>
>> This is not the root case, actually we want put ATF as close as possible to
>> the start of dram, this give linux kernel convenient to manage the memory.
> But instead of 64KB you could put it at 32KB or 128KB. It's still in
> the first 1MB. Linux won't care, right?
>
>>
>>
>>> Does that help you?
>>>
>>>> On the other hand, change the ATF load address will break the
>>>> compatibility of the exiting firmware.
>>> I am not sure what you mean with "compatibility of existing firmware"?
>>> Surely you combine all the firmware components (SPL/TPL/ATF/U-Boot proper)
>>> into one image? And there would be no real mix and match, with older
>>> pre-compiled builds? So by changing the ATF base address and the load
>>> address in TPL at the same time you won't have issues?
>>>
>> I mean older pre-compiled builds published by rockchip rkbin [1], many
>> projects and popular boards directly use this , for example Armbian. How to
>> change the base address of the pre-build binary?
>>   [1] https://github.com/rockchip-linux/rkbin
> Perhaps I am misunderstanding your intent here, but mainline U-Boot
> should not be bound to the design decisions of old closed-source
> binaries.

Indeed rockchip have submit the ATF support for rockchip platforms to 
ATF mainline. But the situation is: we see many people like  directly 
use the pre-build binary from rkbin, they are used on many popular 
boards and projects. Armbian is one of the example for this[0] , it use 
mainline u-boot, but use atf from rkbin for  some boards.

So we are really care about the compatibility.

[0]https://github.com/armbian/build/blob/master/config/sources/rockchip64.conf 
<https://github.com/armbian/build/blob/master/config/sources/rockchip64.conf>

> [...]
>
> Regards,
> Simon
>
>
>