Re: [PATCH] MIPS: ingenic: Add support for appended devicetree

[Paul Cercueil]

Hi Jonas,

On Thu, 21 Feb 2019 at 21:39, Jonas Gorski <jonas.gorski@xxxxxxxxx> 
wrote:
> On Thu, 21 Feb 2019 at 21:39, Paul Cercueil <paul@xxxxxxxxxxxxxxx> 
> wrote:
> >  Add support for booting the kernel from an externally-appended
> >  devicetree, if no devicetree was built-in.
> >
> >  Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> >  ---
> >   arch/mips/Kconfig        |  2 +-
> >   arch/mips/jz4740/setup.c | 14 +++++++++++---
> >   2 files changed, 12 insertions(+), 4 deletions(-)
> >
> >  diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> >  index a84c24d894aa..8b7ea9062198 100644
> >  --- a/arch/mips/Kconfig
> >  +++ b/arch/mips/Kconfig
> >  @@ -391,7 +391,7 @@ config MACH_INGENIC
> >          select GPIOLIB
> >          select COMMON_CLK
> >          select GENERIC_IRQ_CHIP
> >  -       select BUILTIN_DTB
> >  +       select BUILTIN_DTB if MIPS_NO_APPENDED_DTB
> >          select USE_OF
> >          select LIBFDT
> >
> >  diff --git a/arch/mips/jz4740/setup.c b/arch/mips/jz4740/setup.c
> >  index afb40f8bce96..5c00064937c4 100644
> >  --- a/arch/mips/jz4740/setup.c
> >  +++ b/arch/mips/jz4740/setup.c
> >  @@ -31,6 +31,7 @@
> >
> >   #define JZ4740_EMC_SDRAM_CTRL 0x80
> >
> >  +extern const char __appended_dtb;
>
> Does this build/link with MIPS_NO_APPENDED_DTB? I would assume it
> won't be able to resolve the symbol in that case.

Oops. You're right.

> You can also just use fw_passed_dtb from asm/bootinfo.h, which will be
> populated automatically from fw_args (if UHI) or __appended_dtb (if
> present and valid)[1], without having to care where it came from.

Thanks, I will.

Regards,
-Paul