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To: Valentine Barshak <vbarshak@ru.mvista.com>
From: Wolfgang Denk <wd@denx.de>
Subject: Re: Strange behavior with I2C on Sequoia board
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Date: Thu, 21 Aug 2008 20:45:56 +0200
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Dear Valentine Barshak,

In message <48AD5FD1.1090809@ru.mvista.com> you wrote:
> 
> U-boot thinks that all memory above the first 8MB is out of reach for 
> the kernel and puts kernel bootargs and boardinfo structure below 8MB as 
> close as possible to this limit. Including the i2c driver into the 
> kernel increases the kernel image size. So when u-boot unpacks the 
> kernel to 0x400000 (Load Address: 00400000) it overwrites the kernel 
> parameters. So when the kernel actually starts, it reads zeros instead 
> of boardinfo (and mac addresses)
> 
> The 8MB limit is set for all AMCC boards in include/configs/amcc-common.h:
> #define CFG_BOOTMAPSZ		(8 << 20) /* Initial Memory map for Linux */

See also the initrd_high environment variable to adjust the limits
without need for recompiling U-Boot.

Best regards,

Wolfgang Denk

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