1 =======================
2 ARM Linux 2.6 and upper
3 =======================
4
5 Please check <ftp://ftp.arm.linux.org.uk/p
6 updates.
7
8 Compilation of kernel
9 ---------------------
10
11 In order to compile ARM Linux, you will need
12 generating ARM ELF code with GNU extensions.
13 a good compiler. Fortunately, you needn't g
14 an error if your compiler is a recognized of
15
16 To build ARM Linux natively, you shouldn't h
17 in the top level Makefile. However, if you
18 tools installed as default, then you should
19 line as detailed below.
20
21 If you wish to cross-compile, then alter the
22 level make file::
23
24 ARCH = <whatever>
25
26 with::
27
28 ARCH = arm
29
30 and::
31
32 CROSS_COMPILE=
33
34 to::
35
36 CROSS_COMPILE=<your-path-to-your-compiler-
37
38 eg.::
39
40 CROSS_COMPILE=arm-linux-
41
42 Do a 'make config', followed by 'make Image'
43 (arch/arm/boot/Image). A compressed image c
44 'make zImage' instead of 'make Image'.
45
46
47 Bug reports etc
48 ---------------
49
50 Please send patches to the patch system. Fo
51 http://www.arm.linux.org.uk/developer/patche
52 explanation as to what the patch does and wh
53
54 Bug reports should be sent to linux-arm-kern
55 or submitted through the web form at
56 http://www.arm.linux.org.uk/developer/
57
58 When sending bug reports, please ensure that
59 information, eg. the kernel messages that we
60 the problem, what you were doing, etc.
61
62
63 Include files
64 -------------
65
66 Several new include directories have been cr
67 which are there to reduce the clutter in the
68 directories, and their purpose is listed bel
69
70 ============= ==============================
71 `arch-*` machine/platform specific head
72 `hardware` driver-internal ARM specific d
73 `mach` descriptions of generic ARM to
74 `proc-*` processor dependent header fil
75 categories)
76 ============= ==============================
77
78
79 Machine/Platform support
80 ------------------------
81
82 The ARM tree contains support for a lot of d
83 continue supporting these differences, it ha
84 machine-specific parts by directory. For th
85 used to select which directories and files g
86 $(MACHINE) to refer to the category)
87
88 To this end, we now have arch/arm/mach-$(MAC
89 designed to house the non-driver files for a
90 memory management, architecture definitions
91 machines, there should be a corresponding ar
92 directory.
93
94
95 Modules
96 -------
97
98 Although modularisation is supported (and re
99 each module on an ARM2/ARM250/ARM3 machine w
100 memory up to the next 32k boundary due to th
101 Therefore, is modularisation on these machin
102
103 However, ARM6 and up machines allow modules
104 as such Acorn RiscPCs and other architecture
105 make good use of modularisation.
106
107
108 ADFS Image files
109 ----------------
110
111 You can access image files on your ADFS part
112 partition, and then using the loopback devic
113 losetup installed.
114
115 Please note that the PCEmulator DOS partitio
116 the start, and as such, you will have to giv
117
118
119 Request to developers
120 ---------------------
121
122 When writing device drivers which include a
123 include it in with the C file, and not the a
124 allows the driver to be compiled as a loadab
125 half the code to be compiled into the kernel
126
127 In general, try to avoid using assembler unl
128 makes drivers far less easy to port to other
129
130
131 ST506 hard drives
132 -----------------
133
134 The ST506 hard drive controllers seem to be
135 slowly). At the moment they will only work
136 A4x0's motherboard, but for it to work off a
137 someone with a podule to add the addresses f
138 HDC base to the source.
139
140 As of 31/3/96 it works with two drives (you
141 `*configure` harddrive set to 2). I've got a
142 big external 5.25" FH 64MB drive (who could
143
144 I've just got 240K/s off it (a dd with bs=12
145 RiscOS gets; but it's a heck of a lot better
146 last week :-)
147
148 Known bug: Drive data errors can cause a han
149 the controller has fixed the error using ECC
150 in that case...hmm).
151
152
153 1772 Floppy
154 -----------
155 This also seems to work OK, but hasn't been
156 hasn't got any code for disc change detectio
157 could be a bit of a problem! Suggestions on
158 are welcome.
159
160
161 `CONFIG_MACH_` and `CONFIG_ARCH_`
162 ---------------------------------
163 A change was made in 2003 to the macro names
164 Historically, `CONFIG_ARCH_` was used for th
165 e.g. SA1100, as well as implementations of t
166 e.g. Assabet. It was decided to change the
167 to read `CONFIG_MACH_` for clarity. Moreove
168 not been made because it would complicate pa
169
170 Previous registrations may be found online.
171
172 <http://www.arm.linux.org.uk/developer/mac
173
174 Kernel entry (head.S)
175 ---------------------
176 The initial entry into the kernel is via hea
177 independent code. The machine is selected b
178 entry, which must be kept unique.
179
180 Due to the large number of machines which th
181 for, we have a method to manage this which e
182 duplicating large amounts of code.
183
184 We group machine (or platform) support code
185 class typically based around one or more sys
186 acts as a natural container around the actua
187 classes are given directories - arch/arm/mac
188 the source files and include/mach/ to suppor
189
190 For example, the SA1100 class is based upon
191 devices, and contains the code to support th
192 board devices are used, or the device is set
193 machine specific "personality."
194
195 For platforms that support device tree (DT),
196 controlled at runtime by passing the device
197 compile-time, support for the machine type m
198 a single multiplatform kernel build to be us
199
200 For platforms that do not use device tree, t
201 controlled by the machine type ID, which act
202 compile-time code selection method. You can
203 web site at:
204
205 <http://www.arm.linux.org.uk/developer/mac
206
207 Note: Please do not register a machine type
208 platform is DT-only, you do not need a regis
209
210 ---
211
212 Russell King (15/03/2004)
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