X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=doc%2FREADME.generic-board;h=32ddb1d19a274b3960b782b8700ff74807eb0657;hb=ac14bc41692a55d5b53f73a0a5b33de2424c2cb6;hp=bd8eae1992c71f60a2a52fcc5cb7d4388a6ac7a5;hpb=9da7e3daf31d7c0c8478a57544bfdd6245e53ff3;p=oweals%2Fu-boot.git diff --git a/doc/README.generic-board b/doc/README.generic-board index bd8eae1992..32ddb1d19a 100644 --- a/doc/README.generic-board +++ b/doc/README.generic-board @@ -1,33 +1,24 @@ +# SPDX-License-Identifier: GPL-2.0+ # # (C) Copyright 2014 Google, Inc # Simon Glass -# -# SPDX-License-Identifier: GPL-2.0+ -# - -DEPRECATION NOTICE FOR arch//lib/board.c - -For board maintainers: Please submit patches for boards you maintain before -July 2014, to make them use generic board. - -For architecture maintainers: Please submit patches to remove your -architecture-specific board.c file before October 2014. - Background ---------- -U-Boot has traditionally had a board.c file for each architecture. This has -introduced quite a lot of duplication, with each architecture tending to do +U-Boot traditionally had a board.c file for each architecture. This introduced +quite a lot of duplication, with each architecture tending to do initialisation slightly differently. To address this, a new 'generic board -init' feature was introduced a year ago in March 2013 (further motivation is +init' feature was introduced in March 2013 (further motivation is provided in the cover letter below). +All boards and architectures have moved to this as of mid 2016. + What has changed? ----------------- -The main change is that the arch//lib/board.c file is being removed in +The main change is that the arch//lib/board.c file is removed in favour of common/board_f.c (for pre-relocation init) and common/board_r.c (for post-relocation init). @@ -36,55 +27,6 @@ fields which are common to all architectures. Architecture-specific fields have been moved to separate structures. -Supported Arcthitectures ------------------------- - -If you are unlucky then your architecture may not support generic board. -The following architectures are supported now: - - arc - arm - avr32 - blackfin - m68k - microblaze - mips - nios2 - powerpc - sandbox - x86 - -If your architecture is not supported, you need to select -HAVE_GENERIC_BOARD in arch/Kconfig -and test it with a suitable board, as follows. - - -Adding Support for your Board ------------------------------ - -To enable generic board for your board, define CONFIG_SYS_GENERIC_BOARD in -your board config header file. - -Test that U-Boot still functions correctly on your board, and fix any -problems you find. Don't be surprised if there are no problems - generic -board has had a reasonable amount of testing with common boards. - - -DeadLine --------- - -Please don't take this the wrong way - there is no intent to make your life -miserable, and we have the greatest respect and admiration for U-Boot users. -However, with any migration there has to be a period where the old way is -deprecated and removed. Every patch to the deprecated code introduces a -potential breakage in the new unused code. Therefore: - -Boards or architectures not converted over to general board by the -end of 2014 may be forcibly changed over (potentially causing run-time -breakage) or removed. - - - Further Background ------------------ @@ -105,12 +47,12 @@ places. initialisation is painful since it must be independently added in 10 places. -3. As time goes by the architectures naturely diverge since there is limited -pressure to compare features or even CONFIG options against simiilar things +3. As time goes by the architectures naturally diverge since there is limited +pressure to compare features or even CONFIG options against similar things in other board.c files. 4. New architectures must implement all the features all over again, and -sometimes in subtley different ways. This places an unfair burden on getting +sometimes in subtle different ways. This places an unfair burden on getting a new architecture fully functional and running with U-Boot. 5. While it is a bit of a tricky change, I believe it is worthwhile and @@ -190,3 +132,4 @@ convenience. Simon Glass, sjg@chromium.org March 2014 +Updated after final removal, May 2016