From 3b58de4d0b6bde8f8dab0fa0c0dc417e57b6c804 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Thu, 14 Sep 2023 10:55:55 -0600 Subject: Mark DISTRO_DEFAULTS as deprecated Standard boot has been in place for a while now. Quite a few problems have been found and fixed. It seems like a good time to mark the script-based approach as deprecated and encourage people to use standard boot. Update the DISTRO_DEFAULTS Kconfig to encourage people to move to standard boot, which is able to boot Linux distributions automatically. Add a short migration guide to make this easier. Signed-off-by: Simon Glass Reviewed-by: Tom Rini --- doc/develop/bootstd.rst | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'doc/develop/bootstd.rst') diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst index e8b90752f08..6172dc906bd 100644 --- a/doc/develop/bootstd.rst +++ b/doc/develop/bootstd.rst @@ -464,6 +464,28 @@ ready File was loaded and is ready for use. In this state the bootflow is ======= ======================================================================= +Migrating from distro_boot +-------------------------- + +To migrate from distro_boot: + +#. Update your board header files to remove the BOOTENV and BOOT_TARGET_xxx + defines. Standard boot finds available boot devices automatically. + +#. Remove the "boot_targets" variable unless you need it. Standard boot uses a + default order from fastest to slowest, which generally matches the order used + by boards. + +#. Make sure that CONFIG_BOOTSTD_DEFAULTS is enabled by your board, so it can + boot common Linux distributions. + +An example patch is at migrate_patch_. + +If you are using custom boot scripts for your board, consider creating your +own bootmeth to hold the logic. There are various examples at +`boot/bootmeth_...`. + + Theory of operation ------------------- @@ -775,3 +797,4 @@ Other ideas: .. _BootLoaderSpec: http://www.freedesktop.org/wiki/Specifications/BootLoaderSpec/ .. _distro_boot: https://github.com/u-boot/u-boot/blob/master/boot/distro.c .. _bootflow_h: https://github.com/u-boot/u-boot/blob/master/include/bootflow.h +.. _migrate_patch: https://patchwork.ozlabs.org/project/uboot/patch/20230727215433.578830-2-sjg@chromium.org/ -- cgit v1.2.3