[U-Boot] [PATCH 1/4] lib: fdtdec: Fill initial ram top with DDR start value from dt

[Simon Glass]

Hi,


On 7 June 2018 at 06:18, Michal Simek <michal.simek at xilinx.com> wrote:
> Hi,
>
> On 5.6.2018 09:20, Siva Durga Prasad Paladugu wrote:
>> Fill initial ram top with DDR base addr value from DT as not filling
>> it here always assumes it as zero while calculating relocation
>> offset and hence lead to failures in somecases. This will assumed
>> as zero if CONFIG_SYS_SDRAM_BASE is not defined.
>>
>> Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu at xilinx.com>
>> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
>> ---
>>  lib/fdtdec.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/lib/fdtdec.c b/lib/fdtdec.c
>> index f4e8dbf..34ef9b8 100644
>> --- a/lib/fdtdec.c
>> +++ b/lib/fdtdec.c
>> @@ -1172,6 +1172,7 @@ int fdtdec_setup_memory_size(void)
>>       }
>>
>>       gd->ram_size = (phys_size_t)(res.end - res.start + 1);
>> +     gd->ram_top = (unsigned long)res.start;
>>       debug("%s: Initial DRAM size %llx\n", __func__,
>>             (unsigned long long)gd->ram_size);
>>
>>
>
> I am curious about ram_top meaning. It is used more as ram_base.
>
> I expect we can workaround it by board_get_usable_ram_top() where we
> decode it exactly the same as patched fdtdec_setup_memory_size() but I
> don't think it is better solution than this one.
>
> Simon/Tom: any comment?

I wonder why it is not set to res.end in this patch?

Comments from global_data.h:

unsigned long ram_top; /* Top address of RAM used by U-Boot */
phys_size_t ram_size; /* RAM size */

Regards,
Simon