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 sjg@chromium.org ---
(no changes since v3)
Changes in v3: - Drop extra newline and quote
Changes in v2: - Mention in the DISTRO_DEFAULTS option that it is script-based - Expand and rewrite the commit message - Use the word 'Mark' instead of 'Make' to improve the English
boot/Kconfig | 6 +++++- doc/develop/bootstd.rst | 23 +++++++++++++++++++++++ 2 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/boot/Kconfig b/boot/Kconfig index 4ebcf3109113..7ef44a26fb92 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -784,7 +784,7 @@ config SYS_BOOT_RAMDISK_HIGH endmenu # Boot images
config DISTRO_DEFAULTS - bool "Select defaults suitable for booting general purpose Linux distributions" + bool "(deprecated) Script-based booting of Linux distributions" select BOOT_DEFAULTS select AUTO_COMPLETE select CMDLINE_EDITING @@ -792,6 +792,10 @@ config DISTRO_DEFAULTS select HUSH_PARSER select SYS_LONGHELP help + Note: These scripts have been replaced by Standard Boot. Do not use + them on new boards. See 'Migrating from distro_boot' at + doc/develop/bootstd.rst + Select this to enable various options and commands which are suitable for building u-boot for booting general purpose Linux distributions.
diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst index e8b90752f083..6172dc906bde 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...