[U-Boot] [RESEND PATCH v2 1/6] image: Use ram_top, not bi_memsize, in getenv_bootm_size

[Daniel Schwierzeck]

Am 04.05.2017 um 18:49 schrieb Simon Glass:
> Hi Daniel,
> 
> On 30 April 2017 at 13:22, Daniel Schwierzeck
> <daniel.schwierzeck at gmail.com> wrote:
>> From: Paul Burton <paul.burton at imgtec.com>
>>
>> When determining the region of memory to allow for use by bootm, using
>> bi_memstart & adding bi_memsize can cause problems if that leads to an
>> integer overflow. For example on some MIPS systems bi_memstart would be
>> 0xffffffff80000000 (ie. the start of the MIPS ckseg0 region) and if the
>> system has 2GB of memory then the addition would wrap around to 0.
>>
>> The maximum amount of memory to be used by U-Boot is already accounted
>> for by the ram_top field of struct global_data, so make use of that for
>> the calculation instead.
>>
>> Signed-off-by: Paul Burton <paul.burton at imgtec.com>
>> Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
>>
>> ---
>>
>> Changes in v2:
>> - also patch ARM specific code to get a consistent behaviour
>>
>>  common/image.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/common/image.c b/common/image.c
>> index 0f88984f2d..160c4c6fbc 100644
>> --- a/common/image.c
>> +++ b/common/image.c
>> @@ -494,11 +494,10 @@ phys_size_t getenv_bootm_size(void)
>>
>>  #if defined(CONFIG_ARM) && defined(CONFIG_NR_DRAM_BANKS)
>>         start = gd->bd->bi_dram[0].start;
>> -       size = gd->bd->bi_dram[0].size;
>>  #else
>>         start = gd->bd->bi_memstart;
>> -       size = gd->bd->bi_memsize;
>>  #endif
>> +       size = gd->ram_top - start;
>>
> 
> I'm a little nervous about this change. For ARM we might have
> discontinuous DRAM segments. Can you not set bd->bi_memsize insead?
> 
>>         s = getenv("bootm_low");
>>         if (s)

after reviewing again I think this patch is wrong. Maybe we have to fix
the MIPS specific problem instead, where CONFIG_SYS_SDRAM_BASE is used
as a virtual address instead of a physical one. Actually this causes the
wrap around. Thus I withdraw this patch.

-- 
- Daniel

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