[U-Boot] [PATCH 1/6] x86: Support machines with >4GB of RAM

[Bin Meng]

Hi Simon,

On Thu, Feb 26, 2015 at 8:55 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 25 February 2015 at 00:10, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Hi Simon,
>>
>> On Wed, Feb 11, 2015 at 9:59 AM, Simon Glass <sjg at chromium.org> wrote:
>>> Some systems have more than 4GB of RAM. U-Boot can only place things below
>>> 4GB so any memory above that should not be used. Ignore any such memory so
>>> that the memory size will not exceed the maximum.
>>>
>>> This prevents gd->ram_size exceeding 4GB which causes problems for PCI
>>> devices which use DMA.
>>>
>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>> ---
>>>
>>>  arch/x86/cpu/coreboot/sdram.c | 6 ++++--
>>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/x86/cpu/coreboot/sdram.c b/arch/x86/cpu/coreboot/sdram.c
>>> index e98a230..9c3ab81 100644
>>> --- a/arch/x86/cpu/coreboot/sdram.c
>>> +++ b/arch/x86/cpu/coreboot/sdram.c
>>> @@ -90,7 +90,8 @@ int dram_init(void)
>>>                 struct memrange *memrange = &lib_sysinfo.memrange[i];
>>>                 unsigned long long end = memrange->base + memrange->size;
>>>
>>> -               if (memrange->type == CB_MEM_RAM && end > ram_size)
>>> +               if (memrange->type == CB_MEM_RAM && end > ram_size &&
>>> +                   memrange->base < (1ULL << 32))
>>
>> Can we safely assume no single entry in memrange[] lies across the 4GB boundary?
>
> From what I have seen, yes. There always seems to be a hole in memory
> from about 3.3GB to 4GB.

OK, then

Reviewed-by: Bin Meng <bmeng.cn at gmail.com>

>>
>>>                         ram_size = end;
>>>         }
>>>         gd->ram_size = ram_size;
>>> @@ -108,7 +109,8 @@ void dram_init_banksize(void)
>>>                 for (i = 0, j = 0; i < lib_sysinfo.n_memranges; i++) {
>>>                         struct memrange *memrange = &lib_sysinfo.memrange[i];
>>>
>>> -                       if (memrange->type == CB_MEM_RAM) {
>>> +                       if (memrange->type == CB_MEM_RAM &&
>>> +                           memrange->base < (1ULL << 32)) {
>>>                                 gd->bd->bi_dram[j].start = memrange->base;
>>>                                 gd->bd->bi_dram[j].size = memrange->size;
>>>                                 j++;
>>> --

Regards,
Bin