Kernel not booting when supplying boot parameter mem

[Arshad, Farrukh]

Hi Tiejun,

Thanks for your response. Yes, I am running two kernels one on each core in SAMP configuration on P1022RDK board. Given is my memory partitioning. Core 0 is loading fine but Core 1 is not loading. CONFIG_RELOCATABLE is not set.

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Core                      	| Base Address  	|    Size                 			| Uboot parameters					| Kernel Configuration									|
-----------------------------|---------------------------|-------------------------------------|------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------|
Core 0 (MEL RT Kernel) 	| 0x0000,0000   		| 0x1000,0000 - 256 (MB)   	|bootm_low = 0x0000,0000, bootm_size = 0x1000,0000	| CONFIG_PHYSICAL_START = 0x0000,0000, CONFIG_KERNEL_START = 0xC000,0000	|
Core 1 (LTIB Kernel)      	|0x1000,0000    		| 0x0800,0000 - 128 (MB)   	|bootm_low = 0x1000,0000, bootm_size = 0x0800,0000	| CONFIG_PHYSICAL_START = 0x1000,0000, CONFIG_KERNEL_START = 0xC000,0000	|
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Regards,
Farrukh Arshad

-----Original Message-----
From: tiejun.chen [mailto:tiejun.chen at windriver.com] 
Sent: Tuesday, December 27, 2011 4:08 PM
To: Arshad, Farrukh
Cc: linuxppc-dev at lists.ozlabs.org
Subject: Re: Kernel not booting when supplying boot parameter mem

Arshad, Farrukh wrote:
> Greetings All,
> 
> I have a basic question. I have 512 MB memory. I want my kernel to use only last 128 MB of memory starting from address 0x10000000. I have configured the kernel CONFIG_PHYSICAL_START=0x10000000 and in kernel boot parameter I have set mem=128M. In this scenario my kernel is not booting and it just stuck after uncompressing it. If I do not provide mem=128M boot parameter my kernel boots fine, but in that case I can not restrict kernel to use only 128M memory. Why supplying mem=128M causing kernel to fail.
> 

Any kernel option else is configured, such as CONFIG_KERNEL_START and CONFIG_RELOCATABLE?

Or any u-boot argument is reconfigured, such as 'bootm_low', 'bootm_mapsize' and 'bootm_size'.

Tiejun