[U-Boot] [PATCH 4/4] microblaze: generic: enable FDT support

Michal Simek monstr at monstr.eu
Wed Jun 23 08:27:22 CEST 2010


Stephan Linz wrote:
> Am Dienstag, 22. Juni 2010 09:25:56 schrieb Michal Simek:
>> Stephan Linz wrote:
>>> Signed-off-by: Stephan Linz <linz at li-pro.net>
>>> ---
>>>  include/configs/microblaze-generic.h |    8 ++++++++
>>>  1 files changed, 8 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/include/configs/microblaze-generic.h
>>> b/include/configs/microblaze-generic.h index 28cee47..89e6dbb 100644
>>> --- a/include/configs/microblaze-generic.h
>>> +++ b/include/configs/microblaze-generic.h
>>> @@ -305,4 +305,12 @@
>>>  #define CONFIG_SYS_PROMPT_HUSH_PS2 "> "
>>>  #endif
>>>
>>> +/* pass open firmware flat tree */
>>> +#define CONFIG_FIT		1
>>> +#define CONFIG_OF_LIBFDT	1
>>> +
>> that's ok.
>>
>>> +/* Initial Memory map for Linux */
>>> +#define CONFIG_SYS_BOOTMAPSZ	(8 << 20)
>> Why is this value setup to 0x800000?
> 
> First of all the flat device tree handling depends on CONFIG_SYS_BOOTMAPSZ. So 
> I have to define a valid value. As far as I understand the initial memory map 
> for Linux there have to be space for the kernel (text+data), fdt_blob and 
> kernel parameters (at least). I'm unsure with an embedded init ramdisk as 
> produced by simpleImage. The simpleImage can quickly grow up over 6MB with 
> embedded initrd.
> 
> So I borrowed this configuration (8MB) from most other configurations (mainly 
> PowerPC).

ok. Microblaze handles FDT blob in different way. Kernel just need to 
know where it is and then is copied to another place.
We don't have any limits like 8MB or so that's why I prefer to setup 
~0UL value or something like that.

Can you please test it?

Thanks,
Michal

-- 
Michal Simek, Ing. (M.Eng)
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/
Microblaze U-BOOT custodian


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