[PATCH 4/4] ARM: zImage: allow supplementing appended DTB with traditional ATAG data

[Shawn Guo]

On Tue, Jun 21, 2011 at 01:09:15AM -0400, Nicolas Pitre wrote:
> From: Nicolas Pitre <nicolas.pitre at linaro.org>
> 
> Some old bootloaders can't be updated to a device tree capable one,
> yet they provide ATAGs with memory configuration, the ramdisk address,
> the kernel cmdline string, etc.  To allow a device tree enabled
> kernel to be used with such bootloaders, it is necessary to convert those
> ATAGs into FDT properties and fold them into the DTB appended to zImage.
> 
> Currently the following ATAGs are converted:
> 
> 	ATAG_CMDLINE
> 	ATAG_MEM (up to 8 memory regions)
> 	ATAG_INITRD2
> 
> If the corresponding information already exists in the appended DTB, it
> is replaced, otherwise the required node is created to hold it.
> 
> The code looks for ATAGs at the location pointed by the value of r2 upon
> entry into the zImage code.  If no ATAGs are found there, an attempt at
> finding ATAGs at the typical 0x100 offset from start of RAM is made.
> Otherwise the DTB is left unchanged.
> 
> Thisstarted from an older patch from John Bonesio <bones at secretlab.ca>,
> with contributions from David Brown <davidb at codeaurora.org>.
> 
> Signed-off-by: Nicolas Pitre <nicolas.pitre at linaro.org>
> ---

With this patch applied, I saw nothing coming from kernel on imx51
babbage serial port.

-- 
Regards,
Shawn