doc: develop: Describe system configuration

Start by describing in general the best practices for how to implement
configuration of some aspect of U-Boot.  This generally means finding
the right choices for when something should be static or dynamically
configured and enabled.  Then further document when to use CONFIG or CFG
namespaces for static configuration.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
This commit is contained in:
Tom Rini
2022-07-29 12:07:38 -04:00
committed by Heinrich Schuchardt
parent 4e5e374bf9
commit 53d2ab9b5a
3 changed files with 133 additions and 21 deletions

21
README
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@@ -166,27 +166,6 @@ Directory Hierarchy:
Software Configuration:
=======================
Configuration is usually done using C preprocessor defines; the
rationale behind that is to avoid dead code whenever possible.
There are two classes of configuration variables:
* Configuration _OPTIONS_:
These are selectable by the user and have names beginning with
"CONFIG_".
* Configuration _SETTINGS_:
These depend on the hardware etc. and should not be meddled with if
you don't know what you're doing; they have names beginning with
"CONFIG_SYS_".
Previously, all configuration was done by hand, which involved creating
symbolic links and editing configuration files manually. More recently,
U-Boot has added the Kbuild infrastructure used by the Linux kernel,
allowing you to use the "make menuconfig" command to configure your
build.
Selection of Processor Architecture and Board Type:
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