1 =============================================
2 Kernel initialisation parameters on ARM Linux
3 =============================================
4
5 The following document describes the kernel in
6 structure, otherwise known as 'struct param_st
7 for most ARM Linux architectures.
8
9 This structure is used to pass initialisation
10 kernel loader to the Linux kernel proper, and
11 through the kernel initialisation process. As
12 should not be referenced outside of arch/arm/k
13
14 There are a lot of parameters listed in there,
15 below:
16
17 page_size
18 This parameter must be set to the page size
19 will be checked by the kernel.
20
21 nr_pages
22 This is the total number of pages of memory
23 the memory is banked, then this should cont
24 of pages in the system.
25
26 If the system contains separate VRAM, this
27 include this information.
28
29 ramdisk_size
30 This is now obsolete, and should not be use
31
32 flags
33 Various kernel flags, including:
34
35 ===== ========================
36 bit 0 1 = mount root read only
37 bit 1 unused
38 bit 2 0 = load ramdisk
39 bit 3 0 = prompt for ramdisk
40 ===== ========================
41
42 rootdev
43 major/minor number pair of device to mount
44
45 video_num_cols / video_num_rows
46 These two together describe the character s
47 or VGA console character size. They should
48 purpose.
49
50 It's generally a good idea to set these to
51 the equivalent character size of your fbcon
52 all the bootup messages to be displayed cor
53
54 video_x / video_y
55 This describes the character position of cu
56 is otherwise unused. (should not be used fo
57 should not be used for other purposes).
58
59 memc_control_reg
60 MEMC chip control register for Acorn Archim
61 based machines. May be used differently by
62
63 sounddefault
64 Default sound setting on Acorn machines. M
65 different architectures.
66
67 adfsdrives
68 Number of ADFS/MFM disks. May be used diff
69 architectures.
70
71 bytes_per_char_h / bytes_per_char_v
72 These are now obsolete, and should not be u
73
74 pages_in_bank[4]
75 Number of pages in each bank of the systems
76 This is intended to be used on systems wher
77 is non-contiguous from the processors point
78
79 pages_in_vram
80 Number of pages in VRAM (used on Acorn Risc
81 be used by loaders if the size of the video
82 from the hardware.
83
84 initrd_start / initrd_size
85 This describes the kernel virtual start add
86 initial ramdisk.
87
88 rd_start
89 Start address in sectors of the ramdisk ima
90
91 system_rev
92 system revision number.
93
94 system_serial_low / system_serial_high
95 system 64-bit serial number
96
97 mem_fclk_21285
98 The speed of the external oscillator to the
99 which control's the speed of the memory bus
100 Depending upon the speed of the cpu its val
101 0-66 MHz. If no params are passed or a valu
102 then a value of 50 Mhz is the default on 21
103
104 paths[8][128]
105 These are now obsolete, and should not be u
106
107 commandline
108 Kernel command line parameters. Details ca
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