[U-Boot] ARM CONFIG_OF_CONTROL status

[Michal Simek]

2012/6/29 Stephan Linz <linz at li-pro.net>:
> Am Freitag, den 29.06.2012, 10:18 +0200 schrieb Michal Simek:
>> On 06/29/2012 04:32 AM, Simon Glass wrote:
>> > Hi,
>> >
>> > --snip--
>>
>> I have sent support for Microblaze. Currently without dts because I want to clear this part a little bit.
>
> Hi Michal,
>
> looks good, I've been waiting a long time on the FDT support in U-Boot
> for Microblaze -- great -- PS: see my comment on patch 5 ...
>
>>
>> Tegra is using ./arch/arm/dts/tegra20.dtsi and board/nvidia/dts/tegra2-seaboard.dts
>> and they are composed together in dts/Makefile by calling preprocessor.
>> Microblaze will be totally different case because every Microblaze hw design is different.
>
> Yes, that's right. We will never be in the position to define a skeleton
> or a basic platform configuration.
>
>> We can use two main buses (little and big endian) and cpu is also configurable.
>> Based on this for Microblaze is the best solution directly to use dts.
>> (DTS for Microblaze is also generated directly from design tool).
>
> ... directly in the context of a board, not arch/cpu, right?

yes.

>
>>
>>
>> Anyway - here is the bug message I am getting if I use full dts in board/<name>/dts/microblaze.dts
>> and empty arch/microblaze/dts/microblaze.dtsi
>>
>> <stdin>:34:3: error: invalid preprocessing directive #address
>> <stdin>:35:3: error: invalid preprocessing directive #size
>> <stdin>:52:4: error: invalid preprocessing directive #address
>> <stdin>:53:4: error: invalid preprocessing directive #cpus
>> <stdin>:54:4: error: invalid preprocessing directive #size
>> <stdin>:155:4: error: invalid preprocessing directive #address
>> <stdin>:156:4: error: invalid preprocessing directive #size
>> <stdin>:160:5: error: invalid preprocessing directive #gpio
>> <stdin>:192:5: error: invalid preprocessing directive #gpio
>> <stdin>:209:5: error: invalid preprocessing directive #gpio
>> <stdin>:241:5: error: invalid preprocessing directive #gpio
>> <stdin>:267:5: error: invalid preprocessing directive #address
>> <stdin>:268:5: error: invalid preprocessing directive #size
>> <stdin>:394:5: error: invalid preprocessing directive #interrupt
>>
>> This is error for opposite case - empty microblaze.dts and full microblaze.dtsi.
>
> That are CPP errors, because the auto generated xilinx.dts is full of
> CPP pragma like syntax (#something) that are wrong (invalid).

I know what it is.

>
>>
>> make[1]: Entering directory `/mnt/projects/u-boot/dts'
>> rc=$( cat /mnt/projects/u-boot/board/petalogix/dts/microblaze.dts | microblaze-unknown-linux-gnu-gcc -E
>> -P -DARCH_CPU_DTS=\"/mnt/projects/u-boot/arch/microblaze/dts/microblaze.dtsi\" - | { { dtc -R 4 -p 0x1000
>> -O dtb -o dt.dtb - 2>&1 ; echo $? >&3 ; } | grep -v '^DTC: dts->dtb  on file' ; } 3>&1 ) ; \
>>       exit $rc
>> /bin/sh: line 1: exit: too many arguments
>> make[1]: *** [dt.dtb] Error 1
>> make[1]: Leaving directory `/mnt/projects/u-boot/dts'
>>
>>
>> I have just tried to fix it by introducing new CONFIG option for skipping that preprocessor
>> part.
>
> Instead of disable / skipp the CPP step you can hide the auto generated
> xilinx.dts with a second include stage, for example:
>
> board/microblaze/dts/microblaze.dts looks like:
>
> /include/ ARCH_CPU_DTS
> /include/ BOARD_DTS
>
>
> Right, only two lines.   The arch/microblaze/dts/microblaze.dtsi remains
> empty as you have said above. Just new is BOARD_DTS -- with the attached
> patch for dts/Makefile you can copy the auto generated xilinx.dts into
> the specific board directory and the CPP step substitute the right place
> to board/microblaze/microblaze-generic/dts/microblaze.dts
>
> I think there are no side effects with other ports like the tegra2.
>
> If you want you can omit the ARCH_CPU_DTS inclusion. The architectural
> microblaze.dtsi file is empty and (!!) have to be empty, because the DTC
> will break with an error on multiple "/dts-v1/;" lines!
>
> Here is the patch:
>
> diff --git a/dts/Makefile b/dts/Makefile
> index 914e479..b1f47a1 100644
> --- a/dts/Makefile
> +++ b/dts/Makefile
> @@ -36,7 +36,8 @@ $(error Your architecture does not have device tree
> support enabled. \
> Please define CONFIG_ARCH_DEVICE_TREE))
>
> # We preprocess the device tree file provide a useful define
> -DTS_CPPFLAGS := -DARCH_CPU_DTS=
> \"$(SRCTREE)/arch/$(ARCH)/dts/$(CONFIG_ARCH_DEVICE_TREE).dtsi\"
> +DTS_CPPFLAGS := -DARCH_CPU_DTS=
> \"$(SRCTREE)/arch/$(ARCH)/dts/$(CONFIG_ARCH_DEVICE_TREE).dtsi\" \
> +               -DBOARD_DTS=
> \"$(SRCTREE)/board/$(VENDOR)/$(BOARD)/dts/$(DEVICE_TREE).dts\"
>
> all:   $(obj).depend $(LIB)

Not sure if using another dts file will be the best approach.