diff options
| author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
|---|---|---|
| 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-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 | |||
| @@ -0,0 +1,129 @@ | |||
| 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. | ||
