[U-Boot] [PATCH 4/9] armv8: layerscape: Rewrite memory reservation

[york sun]

Reduce CC list.

On 02/14/2017 11:56 AM, Alexander Graf wrote:
>
>
> On 14/02/2017 18:38, york sun wrote:
>> On 02/14/2017 09:00 AM, york.sun at nxp.com wrote:
>>> On 02/14/2017 07:31 AM, Alexander Graf wrote:
>>>>
>>>>
>>>> On 14/02/2017 04:45, York Sun wrote:
>>>>> For ARMv8 Layerscape SoCs, secure memory and MC memorey are reserved
>>>>> at the end of DDR. DDR is spit into two or three banks. This patch
>>>>> reverts commit aabd7ddb and simplifies the calculation of reserved
>>>>> memory, and moves the code into common SoC file. Secure memory is
>>>>> carved out first. DDR bank size is reduced. Reserved memory is then
>>>>> allocated on the top of available memory. U-Boot still has access
>>>>> to reserved memory as data transferring is needed. Device tree is
>>>>> fixed with reduced memory size to hide the reserved memory from OS.
>>>>
>>>> I haven't looked in detail, but could you please ensure that you also
>>>> reserve those regions in the efi_loader memory map?
>>>
>>> I missed efi reserved memory map. Will add in v2 patch.
>>>
>>
>> Alex,
>>
>> Is the misc_init_r() the best place to add such reservation under your
>> code dealing with DP_DDR? It is per board code. As of now, we only have
>> ls2080ardb with efi boot.
>
> Ideally I'd like to make sure efi boot works on all boards, not just
> individual ones. So if you find a more generic place that gets called
> after efi_memory_init(), that would be great.
>
> Since you add a global kconfig define for reserved memory, you can even
> do it inside efi_memory_init() directly for the top-of-ram region.
>

Alex,

I am thinking to add a weak function efi_add_known_memory() to do the 
work you have at the beginning of efi_memory_init(). Then I will add 
this function to arch/arm/cpu/armv8/fsl-layerscape/cpu.c. Since the SoC 
file has the knowledge of DP-DDR and how memory is reserved, it can be 
easily added without risking breaking anything else.

By the way, I failed to run distro boot as I set up before. I am going 
to re-download the DVD ISO file and deploy it again to my USB thumb 
drive. Any tips on running it without installation, i.e. live CD mode? I 
remember last time I did some trick to drop to the shell.

York