Lines Matching +full:board +full:- +full:specific
1 .. SPDX-License-Identifier: GPL-2.0
4 Adding a new board to LinuxSH
7 Paul Mundt <lethal@linux-sh.org>
18 of the board-specific code (with the exception of stboards) ended up
19 in arch/sh/kernel/ directly, with board-specific headers ending up in
20 include/asm-sh/. For the new kernel, things are broken out by board type,
24 Board-specific code::
27 |-- arch
28 | `-- sh
29 | `-- boards
30 | |-- adx
31 | | `-- board-specific files
32 | |-- bigsur
33 | | `-- board-specific files
37 `-- include
38 `-- asm-sh
39 |-- adx
40 | `-- board-specific headers
41 |-- bigsur
42 | `-- board-specific headers
49 `-- arch
50 `-- sh
51 `-- cchips
52 `-- hd6446x
53 `-- hd64461
54 `-- cchip-specific files
57 board-specific headers. Thus, include/asm-sh/hd64461 is home to all of the
58 hd64461-specific headers.
63 |-- arch
64 | `-- sh
65 | |-- kernel
66 | | `-- cpu
67 | | |-- sh2
68 | | | `-- SH-2 generic files
69 | | |-- sh3
70 | | | `-- SH-3 generic files
71 | | `-- sh4
72 | | `-- SH-4 generic files
73 | `-- mm
74 | `-- This is also broken out per CPU family, so each family can
77 `-- include
78 `-- asm-sh
79 |-- cpu-sh2
80 | `-- SH-2 specific headers
81 |-- cpu-sh3
82 | `-- SH-3 specific headers
83 `-- cpu-sh4
84 `-- SH-4 specific headers
87 need to be dealt with by the CPU family specific code.
89 2. Adding a New Board
92 The first thing to determine is whether the board you are adding will be
94 share the same board-specific code with minor differences.
97 board in arch/sh/boards/ and adding rules to hook your board in with the
98 build system (more on this in the next section). However, for board families
99 it makes more sense to have a common top-level arch/sh/boards/ directory
100 and then populate that with sub-directories for each member of the family.
104 should also add a directory in include/asm-sh for headers localized to this
105 board (if there are going to be more than one). In order to interoperate
107 as the arch/sh/boards/ directory name, though if your board is again part of
108 a family, the build system has ways of dealing with this (via incdir-y
112 There are a few things that each board is required to have, both in the
113 arch/sh/boards and the include/asm-sh/ hierarchy. In order to better
114 explain this, we use some examples for adding an imaginary board. For
116 get_system_type() and platform_setup(). For our imaginary board, this
120 * arch/sh/boards/vapor/setup.c - Setup code for imaginary board
135 * this board.
138 /* Start-up imaginary PCI ... */
145 Our new imaginary board will also have to tie into the machvec in order for it
150 - I/O functions to IO memory (inb etc) and PCI/main memory (readb etc).
151 - I/O mapping functions (ioport_map, ioport_unmap, etc).
152 - a 'heartbeat' function.
153 - PCI and IRQ initialization routines.
154 - Consistent allocators (for boards that need special allocators,
155 particularly for allocating out of some board-specific SRAM for DMA
159 consult include/asm-sh/machvec.h for the current state of the machvec.
169 If the board-specific definitions are quite minimalistic, as is the case for
170 the vast majority of boards, simply having a single board-specific header is
173 - add a new file include/asm-sh/vapor.h which contains prototypes for
174 any machine specific IO functions prefixed with the machine name, for
184 somewhere in the board-specific header. Any boards being ported that still
187 - Add machine vector definitions to the board's setup.c. At a bare minimum,
195 - finally add a file arch/sh/boards/vapor/io.c, which contains definitions of
196 the machine specific io functions (if there are enough to warrant it).
202 board-specific code is in place, it's time to look at how to get the
217 machdir-y entry in order to be built. This entry needs to be the name of
218 the board directory as it appears in arch/sh/boards, even if it is in a
219 sub-directory (in which case, all parent directories below arch/sh/boards/
220 need to be listed). For our new board, this entry can look like::
222 machdir-$(CONFIG_SH_VAPOR) += vapor
226 Next, the build system assumes that your include/asm-sh directory will also
229 implicitly appended to incdir-y. The existing code manages this for the
233 This is done by adding an entry to the end of the arch/sh/tools/mach-types
236 implicit checks for your board if you need this somewhere throughout the
241 return -ENODEV;
244 lowercase, regardless of the fact that the mach-types entries are all
248 Now all that's left to do is providing a defconfig for your new board. This
249 way, other people who end up with this board can simply use this config
253 Also, as soon as you have copied over a sample .config for your new board
259 Architecture specific targets (sh):
272 $ make ARCH=sh CROSS_COMPILE=sh4-linux- vapor_defconfig vmlinux
274 which will in turn copy the defconfig for this board, run it through
277 board.