doc: guide for optimizing zephyr

doc/guides/index.rst

@@ -25,3 +25,4 @@ User and Developer Guides
    test/index
    tracing/index
    west/index
+   optimizations/index

doc/guides/optimizations/footprint.rst

@@ -0,0 +1,62 @@
+.. _footprint:
+
+Optimizing for Footprint
+########################
+
+Stack Sizes
+***********
+
+Stack sizes of various system threads are specified generously to allow for
+usage in different scenarios on as many supported platforms as possible. You
+should start the optimization process by reviewing all stack sizes and adjusting
+them for your application:
+
+:option:`CONFIG_ISR_STACK_SIZE`
+  Set to 2048 by default
+
+:option:`CONFIG_MAIN_STACK_SIZE`
+  Set to 1024 by default
+
+:option:`CONFIG_IDLE_STACK_SIZE`
+  Set to 320 by default
+
+:option:`CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE`
+  Set to 1024 by default
+
+:option:`CONFIG_OFFLOAD_WORKQUEUE_STACK_SIZE`
+  Set to 1024 by default
+
+:option:`CONFIG_PRIVILEGED_STACK_SIZE`
+  Set to 1024 by default, depends on userspace feature.
+
+
+Unused Peripherals
+******************
+
+Some peripherals are enabled by default. You can disable unused
+peripherals in your project configuration, for example::
+
+
+        CONFIG_GPIO=n
+        CONFIG_SPI=n
+
+Various Debug/Informational Options
+***********************************
+
+The following options are enabled by default to provide more information about
+the running application and to provide means for debugging and error handling:
+
+:option:`CONFIG_BOOT_BANNER`
+  This option can be disabled to save a few bytes.
+
+:option:`CONFIG_DEBUG`
+  This option can be disabled for production builds
+
+
+MPU/MMU Support
+***************
+
+Depending on your application and platform needs, you can disable MPU/MMU
+support to gain some memory and improve performance.  Consider the consequences
+of this configuration choice though, because you'll lose advanced stack
+checking and support.

doc/guides/optimizations/index.rst

@@ -0,0 +1,11 @@
+.. _optimizations:
+
+Optimizations
+##############
+
+Guides on how to optimize Zephyr for performance, power and footprint.
+
+.. toctree::
+   :maxdepth: 1
+
+   footprint.rst