1 | <?xml version="1.0" encoding="ISO-8859-1"?> |
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2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" |
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3 | "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [ |
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4 | <!ENTITY % general-entities SYSTEM "../../general.ent"> |
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5 | %general-entities; |
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6 | ]> |
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7 | |
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8 | <sect1 id="ch-bootable-yaboot" arch="ppc"> |
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9 | <?dbhtml filename="yaboot.html"?> |
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10 | |
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11 | <title>Making the LFS System Bootable</title> |
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12 | |
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13 | <indexterm zone="ch-bootable-yaboot"> |
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14 | <primary sortas="a-Yaboot">Yaboot</primary> |
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15 | <secondary>configuring</secondary></indexterm> |
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16 | |
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17 | <para os="a">Your shiny new LFS system is almost complete. One of the last |
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18 | things to do is to ensure that the system can be properly booted. The |
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19 | instructions below apply only to NewWorld Macintoshes.</para> |
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20 | |
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21 | <para os="b">Boot loading can be a complex area, so a few cautionary words |
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22 | are in order. Be familiar with the current boot loader and any other |
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23 | operating systems present on the hard drive(s) that need to be bootable. |
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24 | Make sure that an emergency CD is ready to <quote>rescue</quote> the |
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25 | computer if it becomes un-bootable. It is also a good idea to enable booting |
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26 | from Open Firmware in case things go really wrong.</para> |
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27 | |
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28 | <para os="c">Earlier, we compiled and installed the yaboot boot loader software |
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29 | in preparation for this step. The procedure involves writing the bootloader |
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30 | to a bootstrap partition and blessing it so that Open Firmware will boot from |
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31 | it. This is all handled by <command>ybin</command> the yaboot installer.</para> |
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32 | |
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33 | <para os="d">Ybin assembles all the information it needs by reading yaboot.conf, |
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34 | then writes the bootstrap. When booted, the bootstrap provides an initial menu to |
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35 | choose between linux, boot from CD, and e.g. osx (depending on what was in yaboot.conf). |
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36 | If you boot to 'linux', yaboot kicks in and lets you select which kernel to use.</para> |
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37 | |
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38 | <para os="e">Images (kernels) are specified, together with any necessary path, |
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39 | in yaboot.conf - the details are incorporated into the bootloader, but no attempt |
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40 | is made to access or validate the paths until they are selected. There are many |
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41 | possible options that can be specified in yaboot.conf, see the man page for the |
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42 | details. Most people will be able to specify device=hd: (for a single hard disk), |
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43 | but if you have multiple disks, or if you wish to be pedantic, you can specify the |
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44 | full OF path to the device, obtained by running <command>ofpath /dev/hdX</command> |
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45 | .</para> |
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46 | |
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47 | <para os="f">Note that the man page mentions which filesystems yaboot can |
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48 | navigate to find the images - the only linux filesystem type mentioned is ext2. |
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49 | You can use ext3 because that can be read like ext2, but if you wish to use |
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50 | reiserfs or any other filesystem you may need to create a separate boot partition |
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51 | formatted as ext2.</para> |
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52 | |
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53 | <para os="h">Using the above information, determine the appropriate designators |
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54 | for the bootstrap partition and the root partition. For the following example, |
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55 | it is assumed that the bootstrap partition is <filename class="partition">hda2 |
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56 | </filename> and the root partition is <filename class="partition">hda7</filename> |
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57 | . We will also assume that you wish to be able to boot an OSX installation on |
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58 | <filename class="partition">hda4</filename>. Change these items as necessary |
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59 | for your machine.</para> |
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60 | |
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61 | <para os="i">If your machine has a SATA disk, specify the partitions using |
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62 | <filename class="devicefile">/dev/sda7</filename> and so forth in the usual |
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63 | way. At least some of the distros specify a full OF path to the 'device' and |
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64 | to the image(s), such as |
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65 | <filename class="devicefile">device=/ht@0,f2000000/pci@3/k2-sata-root@c/k2-sata@0/disk@0: |
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66 | </filename> for the disk, and |
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67 | <filename class="partition">image=/ht@0,f2000000/pci@3/k2-sata-root@c/k2-sata@0/disk@0:9,/boot/lfskernel-&linux-version; |
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68 | </filename> which definitely works.</para> |
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69 | |
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70 | <para os="k">Create a <quote>yaboot.conf</quote> file defining yaboot's boot |
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71 | menu:</para> |
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72 | |
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73 | <screen os="l" role="nodump"><userinput>cat > /etc/yaboot.conf << "EOF" |
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74 | <literal># Begin /etc/yaboot.conf |
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75 | |
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76 | # By default, yaboot will boot the first menu entry. |
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77 | |
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78 | # Allow 10 seconds before booting the default. |
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79 | # this will also apply to the first-stage os selector |
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80 | timeout=100 |
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81 | |
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82 | # These variables are global |
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83 | # first, where to put the bootstrap partition |
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84 | boot=/dev/hda2 |
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85 | |
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86 | # Which disk to use |
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87 | device=hd: |
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88 | |
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89 | # Default partition for the kernel images |
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90 | partition=7 |
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91 | |
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92 | # default root partition |
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93 | root=/dev/hda7 |
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94 | |
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95 | # where ybin is to find yaboot and ofboot |
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96 | install=/usr/lib/yaboot/yaboot |
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97 | magicboot=/usr/lib/yaboot/ofboot |
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98 | |
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99 | # allow the initial menu to offer CD as an option |
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100 | enablecdboot |
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101 | |
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102 | # allow the initial menu to offer booting from Open Firmware |
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103 | enableofboot |
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104 | |
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105 | # allow the initial menu to boot from mac osx |
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106 | macosx=/dev/hda4 |
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107 | |
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108 | # white on black is boring! |
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109 | # note the spellings : 'fgcolor' but 'light' |
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110 | # in this context, light means 'without high intensity' |
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111 | fgcolor=light-green |
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112 | |
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113 | # The first entry is for LFS. |
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114 | # For all images, the pathname is relative to the filesystem |
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115 | # on which they are situated and can include at most one |
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116 | # directory |
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117 | image=/boot/lfskernel-&linux-version; |
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118 | label=&version; |
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119 | read-only</literal> |
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120 | EOF</userinput></screen> |
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121 | |
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122 | |
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123 | <para os="n">Add an entry for the host distribution, if you have one. It might |
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124 | look something like this if the kernel and initrd are in the host's '/' |
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125 | directory on <filename class="partition">hda6</filename>:</para> |
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126 | |
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127 | <screen os="o" role="nodump"><userinput>cat >> /etc/yaboot.conf << "EOF" |
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128 | <literal>title Debian |
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129 | image=/pci@f4000000/ata-6d/disk@0:6,/vmlinux |
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130 | label=Debian |
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131 | initrd=/pci@f4000000/ata-6d/disk@0:6,/initrd.gz |
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132 | initrd-size=10000 |
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133 | append="root=/dev/hda7" |
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134 | read-only</literal> |
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135 | EOF</userinput></screen> |
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136 | |
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137 | <warning os="r"> |
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138 | <para>The following command will overwrite the current boot loader. |
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139 | Do not run the command if this is not desired.</para> |
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140 | </warning> |
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141 | |
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142 | <screen os="s" role="nodump"><userinput>ybin</userinput></screen> |
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143 | |
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144 | <para os="t">Alternatively, if the bootstrap partition has not already been |
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145 | initialized, perhaps because you are using a Live CD, you will need to use |
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146 | a different command to install the bootloader for the first time:</para> |
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147 | |
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148 | <screen os="u" role="nodump"><userinput>mkofboot</userinput></screen> |
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149 | |
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150 | </sect1> |
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