[U-Boot] [PATCH v2] common/image.c: align usage of fdt_high with initrd_high

[Shawn Guo]

Please hold on this patch.  I found some problem with it.

Regards,
Shawn

On Sat, Jan 07, 2012 at 10:39:53PM +0800, Shawn Guo wrote:
> The commit message of a28afca (Add uboot "fdt_high" enviroment variable)
> states that fdt_high behaves similarly to the existing initrd_high.
> But fdt_high actually has an outstanding difference from initrd_high.
> The former specifies the start address, while the later specifies the
> end address.
> 
> As fdt_high and initrd_high will likely be used together, it'd be nice
> to have them behave same.  The patch changes the behavior of fdt_high
> to have it aligned with initrd_high.
> 
> The document of fdt_high in README is updated with an example to
> demonstrate the usage of this environment variable.
> 
> Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
> ---
> Changes since v1:
>  * Update document of fdt_high with an example to demonstrate the usage
> 
>  README         |    8 ++++++++
>  common/image.c |    6 ++----
>  2 files changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/README b/README
> index ff72e47..1c3713c 100644
> --- a/README
> +++ b/README
> @@ -3619,6 +3619,14 @@ List of environment variables (most likely not complete):
>  
>    fdt_high	- if set this restricts the maximum address that the
>  		  flattened device tree will be copied into upon boot.
> +		  For example, if you have a system with 1 GB memory
> +		  at physical address 0x10000000, while Linux kernel
> +		  only recognizes the first 704 MB as low memory, you
> +		  may need to set fdt_high as 0x3C000000 to have the
> +		  device tree blob be copied to the maximum address
> +		  of the 704 MB low memory, so that Linux kernel can
> +		  access it during the boot procedure.
> +
>  		  If this is set to the special value 0xFFFFFFFF then
>  		  the fdt will not be copied at all on boot.  For this
>  		  to work it must reside in writable memory, have
> diff --git a/common/image.c b/common/image.c
> index 77ca6e4..12ceacf 100644
> --- a/common/image.c
> +++ b/common/image.c
> @@ -1294,10 +1294,8 @@ int boot_relocate_fdt(struct lmb *lmb, char **of_flat_tree, ulong *of_size)
>  		if (desired_addr) {
>  			of_start =
>  			    (void *)(ulong) lmb_alloc_base(lmb, of_len, 0x1000,
> -							   ((ulong)
> -							    desired_addr)
> -							   + of_len);
> -			if (desired_addr && of_start != desired_addr) {
> +							   (ulong)desired_addr);
> +			if (of_start == 0) {
>  				puts("Failed using fdt_high value for Device Tree");
>  				goto error;
>  			}
> -- 
> 1.7.4.1
>