u-boot/doc/README.generic-board

5 # SPDX-License-Identifier:	GPL-2.0+
9 ----------
11 U-Boot traditionally had a board.c file for each architecture. This introduced
13 initialisation slightly differently. To address this, a new 'generic board
21 -----------------
23 The main change is that the arch/<arch>/lib/board.c file is removed in
24 favour of common/board_f.c (for pre-relocation init) and common/board_r.c
25 (for post-relocation init).
28 fields which are common to all architectures. Architecture-specific fields
33 ------------------
35 The full text of the original generic board series is reproduced below.
37 --8<-------------
39 This series creates a generic board.c implementation which contains
40 the essential functions of the major arch/xxx/lib/board.c files.
44 1. There is a lot of repeated code in the board.c files. Any change to
54 in other board.c files.
57 sometimes in subtle different ways. This places an unfair burden on getting
58 a new architecture fully functional and running with U-Boot.
62 the code that is common should be located in common/board.c rather than
63 arch/xxx/lib/board.c.
70 http://lists.denx.de/pipermail/u-boot/2012-January/114499.html
72 This series removes the dependency on generic relocation. So relocation
73 happens as one big chunk and is still completely arch-specific. See the
76 http://lists.denx.de/pipermail/u-boot/2011-December/112928.html
80 http://lists.denx.de/pipermail/u-boot/2012-January/114467.html
83 of simply enabling generic board support for an architecture. It is then up
84 to each board to opt in by defining CONFIG_SYS_GENERIC_BOARD in the board
86 before. This allows both sets of code to co-exist until we are comfortable
89 ARM is a relatively large board.c file and one which I can test, therefore
90 I think it is a good target for this series. On the other hand, x86 is
94 largest and most feature-full board, so hopefully we have all bases
102 way to put architecture-specific fields into a separate header file, but
103 for now I have judged that to be counter-productive.
109 There was dicussion on the list about passing gd_t around as a parameter
110 to pre-relocation init functions. I think this makes sense, but it can
113 While this series needs to stand on its own (as with the link script
115 unification of the board init code. So I hope we can address issues with
116 this in mind, rather than focusing too narrowly on particular ARM, x86 or
119 I have run-tested ARM on Tegra Seaboard only. To try it out, define
120 CONFIG_SYS_GENERIC_BOARD in your board file and rebuild. Most likely on
122 something first :-)
124 I have run this though MAKEALL with CONFIG_SYS_GENERIC_BOARD on for all
126 the board config, which I have sent patches for. The main issue is
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