From mboxrd@z Thu Jan  1 00:00:00 1970
From: York Sun <yorksun@freescale.com>
Date: Tue, 11 Feb 2014 12:03:17 -0800
Subject: [U-Boot] [PATCH] driver/mxc_i2c: Move static data structure to
 global_data
In-Reply-To: <20140211195918.69BCE38032B@gemini.denx.de>
References: <1392069772-24742-1-git-send-email-yorksun@freescale.com>
	<52F98C18.7020402@freescale.com>
	<52FA7915.8000307@boundarydevices.com>
	<52FA7DFD.5060406@freescale.com>
	<20140211195918.69BCE38032B@gemini.denx.de>
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On 02/11/2014 11:59 AM, Wolfgang Denk wrote:
> Dear York Sun,
> 
> In message <52FA7DFD.5060406@freescale.com> you wrote:
>>
>> Thanks for the insight. I am not using SPL either. I need this driver to run
>> before u-boot relocates to DDR. Everything is in flash. I need to find a
>> writable location for the variable srdata. I can put this section in linker script
>>
>>        .data.sram :
>>        {
>>                drivers/i2c/built-in.o (.data)
>>        } > sram
> }
> 
> Please do not invent totally new ways to have writable data before
> relocation.  Use the existing machanisms.  While running from flash,
> we have but what little memory we can find in on-chip memory or SRAM
> or data chace; we use this for the stack and global data (which should
> be kept as small as possible, to allow for a as much stack as possible).
> 
> So ideally keep this data on the stack, and if there is no way around
> it, in the global data structure.
> 

Agreed. I tried to use global data at first, which upsets Tom. Tom suggested to
use linker script. I guess he was under the impression I was using SPL. Let me
try harder to use stack.

York