Subject: [PATCH] arm: rpi: Device tree modifications for U-Boot

From: [email-masked] (Stephen Warren)
Date: Tue, 11 Aug 2015 11:29:55 -0600

On 08/11/2015 11:05 AM, Lucas Stach wrote:
> Hi Simon,
>
> why did you send this to the Tegra ML?

At my request, so that the DT changes could be reviewed by the kernel DT 
reviewers and added to the copy of the DT files in the kernel source 
tree if approved.

My assertion is that DT content should be independent of SW stack. Or 
put another way, all SW stacks should use the same DT content. As such, 
if these properties are needed by U-Boot, and contained in the copy of 
the DT files in the U-Boot source tree, they should also be present in 
the copy of the DT files in the kernel source tree, so the two do not 
become out of sync.

> Am Dienstag, den 11.08.2015, 08:25 -0600 schrieb Simon Glass:
>> This updates the device tree from the kernel version to something suitable
>> for U-Boot:
>>
>> - Add stdout-path alias for console
>> - Mark the /soc node to be available pre-relocation so that the early
>> serial console works (we need the 'ranges' property to be available)

>> diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi
>> index 301c73f..bd6bff6 100644
>> --- a/arch/arm/boot/dts/bcm2835.dtsi
>> +++ b/arch/arm/boot/dts/bcm2835.dtsi
>> @@ -8,6 +8,7 @@
>>
>>   	chosen {
>>   		bootargs = "earlyprintk console=ttyAMA0";
>> +		stdout-path = &uart;
>>   	};
>>
>>   	soc {
>> @@ -16,6 +17,7 @@
>>   		#size-cells = <1>;
>>   		ranges = <0x7e000000 0x20000000 0x02000000>;
>>   		dma-ranges = <0x40000000 0x00000000 0x20000000>;
>> +		u-boot,dm-pre-reloc;
>
> Why do you need this and why should upstream carry your favourite
> bootloaders configuration? This is in no way hardware description.