diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/arm/Setup |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'Documentation/arm/Setup')
-rw-r--r-- | Documentation/arm/Setup | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/Documentation/arm/Setup b/Documentation/arm/Setup new file mode 100644 index 000000000000..0abd0720d7ed --- /dev/null +++ b/Documentation/arm/Setup | |||
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1 | Kernel initialisation parameters on ARM Linux | ||
2 | --------------------------------------------- | ||
3 | |||
4 | The following document describes the kernel initialisation parameter | ||
5 | structure, otherwise known as 'struct param_struct' which is used | ||
6 | for most ARM Linux architectures. | ||
7 | |||
8 | This structure is used to pass initialisation parameters from the | ||
9 | kernel loader to the Linux kernel proper, and may be short lived | ||
10 | through the kernel initialisation process. As a general rule, it | ||
11 | should not be referenced outside of arch/arm/kernel/setup.c:setup_arch(). | ||
12 | |||
13 | There are a lot of parameters listed in there, and they are described | ||
14 | below: | ||
15 | |||
16 | page_size | ||
17 | |||
18 | This parameter must be set to the page size of the machine, and | ||
19 | will be checked by the kernel. | ||
20 | |||
21 | nr_pages | ||
22 | |||
23 | This is the total number of pages of memory in the system. If | ||
24 | the memory is banked, then this should contain the total number | ||
25 | of pages in the system. | ||
26 | |||
27 | If the system contains separate VRAM, this value should not | ||
28 | include this information. | ||
29 | |||
30 | ramdisk_size | ||
31 | |||
32 | This is now obsolete, and should not be used. | ||
33 | |||
34 | flags | ||
35 | |||
36 | Various kernel flags, including: | ||
37 | bit 0 - 1 = mount root read only | ||
38 | bit 1 - unused | ||
39 | bit 2 - 0 = load ramdisk | ||
40 | bit 3 - 0 = prompt for ramdisk | ||
41 | |||
42 | rootdev | ||
43 | |||
44 | major/minor number pair of device to mount as the root filesystem. | ||
45 | |||
46 | video_num_cols | ||
47 | video_num_rows | ||
48 | |||
49 | These two together describe the character size of the dummy console, | ||
50 | or VGA console character size. They should not be used for any other | ||
51 | purpose. | ||
52 | |||
53 | It's generally a good idea to set these to be either standard VGA, or | ||
54 | the equivalent character size of your fbcon display. This then allows | ||
55 | all the bootup messages to be displayed correctly. | ||
56 | |||
57 | video_x | ||
58 | video_y | ||
59 | |||
60 | This describes the character position of cursor on VGA console, and | ||
61 | is otherwise unused. (should not used for other console types, and | ||
62 | should not be used for other purposes). | ||
63 | |||
64 | memc_control_reg | ||
65 | |||
66 | MEMC chip control register for Acorn Archimedes and Acorn A5000 | ||
67 | based machines. May be used differently by different architectures. | ||
68 | |||
69 | sounddefault | ||
70 | |||
71 | Default sound setting on Acorn machines. May be used differently by | ||
72 | different architectures. | ||
73 | |||
74 | adfsdrives | ||
75 | |||
76 | Number of ADFS/MFM disks. May be used differently by different | ||
77 | architectures. | ||
78 | |||
79 | bytes_per_char_h | ||
80 | bytes_per_char_v | ||
81 | |||
82 | These are now obsolete, and should not be used. | ||
83 | |||
84 | pages_in_bank[4] | ||
85 | |||
86 | Number of pages in each bank of the systems memory (used for RiscPC). | ||
87 | This is intended to be used on systems where the physical memory | ||
88 | is non-contiguous from the processors point of view. | ||
89 | |||
90 | pages_in_vram | ||
91 | |||
92 | Number of pages in VRAM (used on Acorn RiscPC). This value may also | ||
93 | be used by loaders if the size of the video RAM can't be obtained | ||
94 | from the hardware. | ||
95 | |||
96 | initrd_start | ||
97 | initrd_size | ||
98 | |||
99 | This describes the kernel virtual start address and size of the | ||
100 | initial ramdisk. | ||
101 | |||
102 | rd_start | ||
103 | |||
104 | Start address in sectors of the ramdisk image on a floppy disk. | ||
105 | |||
106 | system_rev | ||
107 | |||
108 | system revision number. | ||
109 | |||
110 | system_serial_low | ||
111 | system_serial_high | ||
112 | |||
113 | system 64-bit serial number | ||
114 | |||
115 | mem_fclk_21285 | ||
116 | |||
117 | The speed of the external oscillator to the 21285 (footbridge), | ||
118 | which control's the speed of the memory bus, timer & serial port. | ||
119 | Depending upon the speed of the cpu its value can be between | ||
120 | 0-66 MHz. If no params are passed or a value of zero is passed, | ||
121 | then a value of 50 Mhz is the default on 21285 architectures. | ||
122 | |||
123 | paths[8][128] | ||
124 | |||
125 | These are now obsolete, and should not be used. | ||
126 | |||
127 | commandline | ||
128 | |||
129 | Kernel command line parameters. Details can be found elsewhere. | ||