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author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2022-07-20 07:50:41 +0200 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2022-08-09 09:39:13 +0200 |
commit | 291dd36e4adec5ad2d873123c1eca2b990d67b7b (patch) | |
tree | 9209d21402eb9b33dba60c1d28b0b1994fabbd01 /Documentation/devicetree | |
parent | 2fc6302090cd77c368cf784adf91dc2beb71764c (diff) | |
download | barebox-291dd36e4adec5ad2d873123c1eca2b990d67b7b.tar.gz barebox-291dd36e4adec5ad2d873123c1eca2b990d67b7b.tar.xz |
bootsource: allow DT aliases and bootrom numbering to differ
So far, we had no explicit mapping table between bootsource_instance
and device id numbering in barebox and mostly depended on DT aliases
reflecting the numbering of the bootrom. Add a new bootsource_set()
that optionally consults a mapping table in the DT to arrive at the
correct numbers.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20220720055042.3510276-3-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r-- | Documentation/devicetree/bindings/barebox/aliases.rst | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/barebox/aliases.rst b/Documentation/devicetree/bindings/barebox/aliases.rst new file mode 100644 index 0000000000..527cc85ef6 --- /dev/null +++ b/Documentation/devicetree/bindings/barebox/aliases.rst @@ -0,0 +1,36 @@ +barebox DT aliases +================== + +barebox can use the properties in the ``/aliases`` node to arrive +at deterministic names for devices, e.g.:: + +.. code-block:: none + / { + aliases { + mmc0 = &sdhci; + wdog0 = &iwdg; + }; + }; + +will assign the MMC device created from probing the node at ``&sdhci`` +the name ``/dev/mmc0``. Similarly, the watchdog device created from +probing the node at ``&iwdg`` will be named ``wdog0``. + +By default, barebox will assume the aliases in the DT to align with +the bootsource communicated by the firmware. If this is not the case, +a device tree override is possible via an +``/aliases/barebox,bootsource-${bootsource}${bootsource_instance}`` +property: + +.. code-block:: none + + &{/aliases} { + mmc0 = &sdmmc0; + mmc1 = &sdhci; + barebox,bootsource-mmc0 = &sdhci; + barebox,bootsource-mmc1 = &sdmmc0; + }; + +This will ensure that when booting from MMC, ``/dev/mmc${bootsource_instance}`` +will point at the correct boot device, despite bootrom and board DT alias +order being different. |