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diff --git a/docs/gnulinux/grub_config.html b/docs/gnulinux/grub_config.html new file mode 100644 index 0000000..2891ebc --- /dev/null +++ b/docs/gnulinux/grub_config.html @@ -0,0 +1,160 @@ +<!DOCTYPE html> +<html> +<head> + <meta charset="utf-8"> + <meta name="viewport" content="width=device-width, initial-scale=1"> + + <style type="text/css"> + @import url('../css/main.css'); + </style> + + <title>Writing a GRUB configuration file</title> +</head> + +<body> + <div class="section"> + <h1 id="pagetop">Writing a GRUB configuration file</h1> + + <p> + <a href="index.html">Back to index</a> + </p> + </div> + + <div class="section"> + + <h1>Table of Contents</h1> + + <li> + <a href="#example_modifications">Example modifications for <i>grubtest.cfg</i></a> + <ul> + <li><a href="#example_modifications_trisquel">Trisquel GNU/Linux-libre</a></li> + <li><a href="#example_modifications_parabola">Parabola GNU/Linux-libre</a></li> + </ul> + </li> + + </div> + + <div class="section"> + <h2 id="example_modifications">Example modifications for <i>grubtest.cfg</i></h2> + + <p> + These are some common examples of ways in which the grubtest.cfg file can be modified. + </p> + + + <div class="subsection"> + <h3 id="example_modifications_trisquel">Trisquel GNU/Linux-libre</h3> + + <p> + As an example, on my test system in /boot/grub/grub.cfg (on the HDD/SSD) I see for the main menu entry: + </p> + <ul> + <li><b>linux /boot/vmlinuz-3.15.1-gnu.nonpae root=UUID=3a008e14-4871-497b-95e5-fb180f277951 ro crashkernel=384M-2G:64M,2G-:128M quiet splash $vt_handoff</b></li> + <li><b>initrd /boot/initrd.img-3.15.1-gnu.nonpae</b></li> + </ul> + + <p> + <b>ro</b>, <b>quiet</b>, <b>splash</b>, <b>crashkernel=384M-2G:64M,2G-:128M</b> and + <b>$vt_handoff</b> can be safely ignored. + </p> + + <p> + I use this to get my partition layout:<br/> + $ <b>lsblk</b> + </p> + + <p> + In my case, I have no /boot partition, instead /boot is on the same partition as / on sda1. + Yours might be different. In GRUB terms, sda means ahci0. 1 means msdos1, or gpt1, depending + on whether I am using MBR or GPT partitioning. Thus, /dev/sda1 is GRUB is (ahci0,msdos1) or + (ahci0,gpt1). In my case, I use MBR partitioning so it's (ahci0,msdos1). + 'msdos' is a GRUB name simply because this partitioning type is traditionally used by MS-DOS. + It doesn't mean that you have a proprietary OS. + </p> + + <p> + Trisquel doesn't keep the filenames of kernels consistent, instead it keeps old kernels and + new kernel updates are provided with the version in the filename. This can make GRUB payload + a bit tricky. Fortunately, there are symlinks /vmlinuz and /initrd.img + so if your /boot and / are on the same partition, you can set GRUB to boot from that. + These are also updated automatically when installing kernel updates from your distributions + apt-get repositories. + <b> + Note: when using <a href="http://jxself.org/linux-libre">jxself kernel releases</a>, + these are not updated at all and you have to update them manually. + </b> + </p> + + <p> + For the GRUB payload grubtest.cfg (in the 'Load Operating System' menu entry), we therefore have (in this example):<br/> + <b>set root='ahci0,msdos1'</b><br/> + <b>linux /vmlinuz root=UUID=3a008e14-4871-497b-95e5-fb180f277951</b><br/> + <b>initrd /initrd.img</b> + </p> + + <p> + Optionally, you can convert the UUID to its real device name, for example /dev/sda1 in this case. + sdX naming isn't very reliable, though, which is why UUID is used for most distributions. + </p> + + <p> + Alternatively, if your /boot is on a separate partition then you cannot rely on the /vmlinuz and /initrd.img symlinks. + Instead, go into /boot and create your own symlinks (update them manually when you install a new kernel update).<br/> + $ <b>sudo -s</b><br/> + # <b>cd /boot/</b><br/> + # <b>rm -Rf vmlinuz initrd.img</b><br/> + # <b>ln -s <u>kernel</u> ksym</b><br/> + # <b>ln -s <u>initrd</u> isym</b><br/> + # <b>exit</b> + </p> + + <p> + Replace the underlined <b>kernel</b> and <b>initrd</b> filenames above with the actual filenames, of course. + </p> + + <p> + Then your grubtest.cfg menu entry (for payload) becomes like that, for example if / was on sda2 and /boot was on sda1:<br/> + <b>set root='ahci0,msdos1'</b><br/> + <b>linux /ksym root=/dev/sda2</b><br/> + <b>initrd /isym</b> + </p> + + <p> + There are lots of possible variations so please try to adapt. + </p> + + </div> + + <div class="subsection"> + <h3 id="example_modifications_parabola">Parabola GNU/Linux-libre</h3> + + <p> + You can basically adapt the above. Note however that Parabola does not keep old kernels still installed, and the file names + are always consistent, so you don't need to boot from symlinks, you can just use the real thing directly. + </p> + </div> + + <p> + <a href="#pagetop">Back to top of page.</a> + </p> + + </div> + + <div class="section"> + + <p> + Copyright © 2014, 2015 Francis Rowe <info@gluglug.org.uk><br/> + This document is released under the Creative Commons Attribution-ShareAlike 4.0 International Public License and all future versions. + A copy of the license can be found at <a href="../cc-by-sa-4.txt">../cc-by-sa-4.txt</a>. + </p> + + <p> + This document is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See <a href="../cc-by-sa-4.txt">../cc-by-sa-4.txt</a> for more information. + </p> + + </div> + +</body> +</html> |