[U-Boot] [PATCH 3/3] rockchip: fix incorrect detection of ram size

[klaus.goger at theobroma-systems.com]

> On 06.05.2018, at 22:03, Marty E. Plummer <hanetzer at startmail.com> wrote:
> 
> On Sun, May 06, 2018 at 02:08:25PM -0500, Marty E. Plummer wrote:
>>> On Sun, May 06, 2018 at 08:39:23PM +0200, klaus.goger at theobroma-systems.com wrote:
>>>> On 06.05.2018, at 16:25, Marty E. Plummer <hanetzer at startmail.com> wrote:
>>>> +		 * we use the 0x00000000~0xfeffffff space
>>>> +		 * since 0xff000000~0xffffffff is soc register space
>>>> +		 * so we reserve it 
>>>> +		 */
>>> 
>>> That's not true for all Rockchip SoCs. On the RK3399 for example the upper limit 
>>> is 0xf8000000. Even on the RK3288 DRAM address range is actually
>>> 0x00000000-0xfe00000
>>> 
>>>> +		size_mb = min(size_mb, 0xff000000/SZ_1M);
>>>> 	}
>>> 
>>> Should be 0xfe000000 (4G-32MB) for RK3288.
>>> But there is already a define for that, SDRAM_MAX_SIZE is defined in
>>> rkxxx_common.h. Using that one would help to avoid possible breakage
>>> of other Rockchip SoCs.
>>> 
>> Oh, does that get #defined properly for each SoC? if so, I'll sub that
>> in for better compat.
> In fact, could you or someone else help me to understand the #include
> chain here? I'm not certain as to what that is available in each header
> mentioned can be used in this file to get max compat across the rockchip
> lineup, and I don't want to break someone elses board/etc with something
> that 'works for me’.

You can get a full list of included headers by adding the -H file to the gcc command line.
make V=1 will help you to see how it’s called on your system.

In that particular case the relevant include chain is:
. include/common.h
.. include/config.h
... include/configs/popmetal_rk3288.h
.... include/configs/rk3288_common.h

So the correct rk3xxx_common.h will be selected by config.h and SDRAM_MAX_SIZE
is defined in all of them.