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howtos:slackware_admin:set_up_syslinux_as_boot_loader_on_uefi_based_hardware [2016/08/17 10:20 (UTC)] tonberry typo |
howtos:slackware_admin:set_up_syslinux_as_boot_loader_on_uefi_based_hardware [2016/08/18 23:46 (UTC)] tonberry typos |
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===== Why UEFI ===== | ===== Why UEFI ===== |
It is not as though there is some choice; machines nowadays //are// UEFI. One can, however, chose to set UEFI to so called "CSM" or sometimes "Legacy" mode. In this mode, UEFI acts as BIOS, i.e. reads the first sector (MBR) of a hard drive and loads and executes non-UEFI boot loader such as LILO from there. As opposed to UEFI in, say, UEFI mode, when it reads, loads and executes UEFI-aware boot loader from //EFI boot partition//. | It is not as though there is some choice; machines nowadays //are// UEFI. One can, however, choose to set UEFI to so called "CSM" or sometimes "Legacy" mode. In this mode, UEFI acts as BIOS, i.e. reads the first sector (MBR) of a hard drive and loads and executes non-UEFI boot loader such as LILO from there. As opposed to UEFI in, say, UEFI mode, when it reads, loads and executes UEFI-aware boot loader from //EFI boot partition//. |
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Frankly, there are no compelling reasons not to use CSM (note that it is possible to use [[http://docs.slackware.com/howtos:slackware_admin:installing_with_gpt_without_uefi | GPT partitions without UEFI]]). On the contrary, there are reasons to avoid UEFI booting, because: | Frankly, there are no compelling reasons not to use CSM (note that it is possible to use [[http://docs.slackware.com/howtos:slackware_admin:installing_with_gpt_without_uefi | GPT partitions without UEFI]]). On the contrary, there are reasons to avoid UEFI booting, because: |
But before you begin: | But before you begin: |
* back up your data, if you have anything of value on any of drives in the machine | * back up your data, if you have anything of value on any of drives in the machine |
* boot to UEFI setup ("BIOS") and verify that boot method is set to "UEFI" not "CMS" or "Legacy" | * boot to UEFI setup ("BIOS") and verify that boot method is set to "UEFI", not "CMS" or "Legacy" |
* and also that Secure Boot is turned off (installation is probably feasible with secure boot on too, but at cost of needless hassle) | * and also that Secure Boot is turned off |
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==== Create EFI Boot Partition ==== | ==== Create EFI Boot Partition ==== |
</code> | </code> |
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That is pretty much it for EFI boot partition. You can do whatever you like with /dev/sda2 (RAID, LUKS, LVM, any filesystem) and install Slackware there, but leave EFI partition alone, that partition needs to be unencrypted and FAT32 formatted. | That is pretty much it for EFI boot partition. You can do whatever you like with /dev/sda3 (RAID, LUKS, LVM, any filesystem) and install Slackware there, but leave EFI partition alone, that partition needs to be unencrypted and FAT32 formatted. |
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* ''LINUX vmlinuz-huge-4.4.14'' tells the boot loader to boot kernel vmlinuz-4.4.14 from the same directory (i.e. EFI\SYSLINUX\vmlinuz-4.4.14) | * ''LINUX vmlinuz-huge-4.4.14'' tells the boot loader to boot kernel vmlinuz-4.4.14 from the same directory (i.e. EFI\SYSLINUX\vmlinuz-4.4.14) |
* ''APPEND /dev/vgroot/V_ROOT 4'' is kernel command line telling the kernel to mount /dev/vgroot/V_ROOT as / (root). Obviously that is a logical volume in this case, but it could be e.g. plain /dev/sda2. The second argument, '4', will be in fact passed by kernel to init, which will start to runlevel 4 instead of default 3 (as per /etc/inittab), i.e. will start to graphical multi-user mode with X window system. | * ''APPEND /dev/vgroot/V_ROOT 4'' is kernel command line telling the kernel to mount /dev/vgroot/V_ROOT as / (root). Obviously that is a logical volume in this case, but it could be e.g. plain /dev/sda2. The second argument, '4', will be in fact passed by kernel to init, which will start to runlevel 4 instead of default 3 (as per /etc/inittab), i.e. will start to graphical multi-user mode with X window system. |
* ''INITRD initrd.gz-4.4.14'' is an initrd image that is mounted as temporary / before the final / is mounted. Typically, an initrd is needed if kernel has to load some additional modules to access the root devite, or has to perform some actions to make it accessible (think of RAID, LUKS, LVM). If you do not need initrd, simply delete this line. | * ''INITRD initrd.gz-4.4.14'' is an initrd image that is mounted as temporary / before the final / is mounted. Typically, an initrd is needed if kernel has to load some additional modules to access the root device, or has to perform some actions to make it accessible (think of RAID, LUKS, LVM). If you do not need initrd, simply delete this line. |
* The second menu entry is largely the same, except that there is no '4' in ''APPEND /dev/vgroot/V_ROOT''. Simply put, this is non-graphical safe mode. If X window system fails to start for whatever reason, you may end up with not only black screen, but also blocked keyboard and mouse and therefore unable to fix the cause. So it is a good idea to have this option prepared beforehand (another method to use otherwise unusable machine with broken X is to SSH-in, though it is a less reliable method). | * The second menu entry is largely the same, except that there is no '4' in ''APPEND /dev/vgroot/V_ROOT''. Simply put, this is non-graphical safe mode. If X window system fails to start for whatever reason, you may end up with not only black screen, but also blocked keyboard and mouse and therefore unable to fix the cause. So it is a good idea to have this option prepared beforehand (another method to use otherwise unusable machine with broken X is to SSH-in, though it is a less reliable method). |
<file /boot/efi/EFI/SYSLINUX/syslinux.cfg> | <file - /boot/efi/EFI/SYSLINUX/syslinux.cfg> |
UI menu.c32 | UI menu.c32 |
PROMPT 0 | PROMPT 0 |