[U-Boot] [PATCH] arm: vf610: move device tree after kernel image

[Stefan Agner]

Hi Tom,

On 2015-10-14 05:39, Tom Rini wrote:
> On Tue, Oct 13, 2015 at 11:11:45PM -0700, Stefan Agner wrote:
> 
>> Since the device tree relocation is disabled (fdt_high set to
>> 0xffffffff), U-Boot keeps the device tree at its load address
>> 0x81000000. The kernel uncompresses itself to 0x80008000 by
>> default, hence this limits the maximum (uncompressed) kernel
>> size to somewhat below 16MiB, otherwise the device tree gets
>> overwritten by the kernel data...
>>
>> Move the device tree load address to 0x84000000 to avoid that
>> the device tree being overwritten by the kernel.
>>
>> Signed-off-by: Stefan Agner <stefan at agner.ch>
>> ---
>>  include/configs/vf610twr.h | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/include/configs/vf610twr.h b/include/configs/vf610twr.h
>> index 324ba8f..1d15f35 100644
>> --- a/include/configs/vf610twr.h
>> +++ b/include/configs/vf610twr.h
>> @@ -129,7 +129,7 @@
>>  	"fdt_high=0xffffffff\0" \
>>  	"initrd_high=0xffffffff\0" \
>>  	"fdt_file=vf610-twr.dtb\0" \
>> -	"fdt_addr=0x81000000\0" \
>> +	"fdt_addr=0x84000000\0" \
>>  	"boot_fdt=try\0" \
>>  	"ip_dyn=yes\0" \
>>  	"mmcdev=" __stringify(CONFIG_SYS_MMC_ENV_DEV) "\0" \
> 
> OK, this is all wrong :(  Please take a look at
> include/configs/ti_armv7_common.h and DEFAULT_LINUX_BOOT_ENV (and the
> giant comment block explaining the values).

This default environment is quite old, and according to the log it came
from Timesys/Freescales initial BSP.

The end of the DDR is commonly used for the second Cortex-M4 core. Hence
I guess fdt_high=0xffffffff has been set to avoid that U-Boot relocates
the device tree into the DDR area used by the M4. Note that this board
only has 128MiB of RAM,

I see that the comments in ti_armv7_common.h is mostly about moving
stuff into the upper 128MiB, which we don't have. So, with these two
things in mind, what do you want me to do differently?

--
Stefan