Re: [PATCH] dt-bindings: u-boot: Add a few more options bindings

On Fri, Nov 19, 2021 at 6:04 PM Simon Glass sjg@chromium.org wrote:

This adds three new options with varying degree of interest / precedent.

Send these to devicetree-spec list so it's not in the flood of devicetree-discuss.

This being sent to the mailing list since it might attract more review. A PR will be sent when this has had some review. That is why the file path is set up for https://github.com/devicetree-org/dt-schema rather than the Linux kernel.

Signed-off-by: Simon Glass sjg@chromium.org

schemas/options/u-boot.yaml | 51 +++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+)

diff --git a/schemas/options/u-boot.yaml b/schemas/options/u-boot.yaml index 71dfda7..b8bdec1 100644 --- a/schemas/options/u-boot.yaml +++ b/schemas/options/u-boot.yaml @@ -71,6 +71,37 @@ properties: 2: use simplified command line (e.g. avoid hush) 3... reserved

• load-environment:
• $ref: /schemas/types.yaml#/definitions/uint32
• default: 1
• maximum: 1
• description: |

•  This allows control over whether U-Boot loads its environment after
  

•  relocation. This normally happens automatically, but can pose a security
  

•  risk, so disabling it in certain situations is useful.
  

•  Note: This could be a boolean. It is defined as an integer since that
  

•  allows changing the value without resizing the devicetree. I'm not sure
  

•  how ugly that is, but IMO the fact that 'false' boolean values are
  

•  represented by being missing is a bit of a pain. One must either add or
  

But they do save space. ;)

•  delete the property.
  

•  Values:
  

•  0: don't load the environment
  

•  1: do load the environment
  

• no-apm-final:
• $ref: /schemas/types.yaml#/definitions/flag
• description: |

•  For devices running on coreboot, this tells U-Boot not to lock down the
  

•  Intel Management Engine (ME) registers. This allows U-Boot to access the
  

•  hardware more fully for platforms that need it.
  

•  Absence of this property indicates that the ME registers should be locked
  

•  down as part of U-Boot's start-up sequence and before the command line is
  

•  available.
  

Perhaps prefix with 'intel' given it is Intel specific.

• silent-console: $ref: /schemas/types.yaml#/definitions/uint32 default: 0

@@ -88,6 +119,23 @@ properties: enabled) 2: console output is suppressed and not recorded

• spl-payload-offset:
• $ref: /schemas/types.yaml#/definitions/uint32
• default: 0
• description: |

•  If present (and SPL is controlled by the devicetree), this allows the
  

•  offset of the SPL payload (typically U-Boot) to be specified. The offset
  

•  is in bytes from the start of the media (typically SPI flash).
  

•  Note: This is quite widely used in U-Boot, but since v2018.01 it is
  

•  possible to use Binman instead, to provide this offset (and various
  

•  others) to SPL, or even to U-Boot proper. So far I have not tried sending
  

•  the Binman bindings upstream, but perhaps that should be done instead.
  

At this point, you are the upstream for binman...

•  See here for details:
  

•  https://u-boot.readthedocs.io/en/latest/develop/package/binman.html#image-description-format
  

required:

• compatible

@@ -101,6 +149,9 @@ examples: bootcmd = "vboot go auto"; bootdelay-sec = <(-1)>; bootsecure = <1>;

•    load-environment = <0>;
  

•    no-apm-final;
     silent-console = <1>;
  

•    spl-payload-offset = <0x40000>;   /* 256K */
   };
  

  };

-- 2.34.0.rc2.393.gf8c9666880-goog