u-boot/doc/README.generic-board

1 # SPDX-License-Identifier: GPL-2.0+
7 ----------
9 U-Boot traditionally had a board.c file for each architecture. This introduced
11 initialisation slightly differently. To address this, a new 'generic board
19 -----------------
21 The main change is that the arch/<arch>/lib/board.c file is removed in
22 favour of common/board_f.c (for pre-relocation init) and common/board_r.c
23 (for post-relocation init).
26 fields which are common to all architectures. Architecture-specific fields
31 ------------------
33 The full text of the original generic board series is reproduced below.
35 --8<-------------
37 This series creates a generic board.c implementation which contains
38 the essential functions of the major arch/xxx/lib/board.c files.
42 1. There is a lot of repeated code in the board.c files. Any change to
52 in other board.c files.
56 a new architecture fully functional and running with U-Boot.
60 the code that is common should be located in common/board.c rather than
61 arch/xxx/lib/board.c.
68 http://lists.denx.de/pipermail/u-boot/2012-January/114499.html
71 happens as one big chunk and is still completely arch-specific. See the
74 http://lists.denx.de/pipermail/u-boot/2011-December/112928.html
78 http://lists.denx.de/pipermail/u-boot/2012-January/114467.html
81 of simply enabling generic board support for an architecture. It is then up
82 to each board to opt in by defining CONFIG_SYS_GENERIC_BOARD in the board
84 before. This allows both sets of code to co-exist until we are comfortable
87 ARM is a relatively large board.c file and one which I can test, therefore
92 largest and most feature-full board, so hopefully we have all bases
100 way to put architecture-specific fields into a separate header file, but
101 for now I have judged that to be counter-productive.
108 to pre-relocation init functions. I think this makes sense, but it can
113 unification of the board init code. So I hope we can address issues with
117 I have run-tested ARM on Tegra Seaboard only. To try it out, define
118 CONFIG_SYS_GENERIC_BOARD in your board file and rebuild. Most likely on
120 something first :-)
124 the board config, which I have sent patches for. The main issue is
131 ------------->8--