byebyebios(1)

1BYEBYEBIOS(1)               Virtualization Support               BYEBYEBIOS(1)
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NAME

6       byebyebios - x86 boot sector injector
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SYNOPSIS

9       byebyebios [OPTION]... RAW-DISK-IMAGE
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11       byebyebios [OPTION]... BLOCK-DEVICE
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DESCRIPTION

14       The byebyebios tool is to be used when an operating system installation
15       for the x86 architecture is only intended to boot via UEFI firmware.
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17       When pointed to either a raw disk image file, or a block  device,  con‐
18       taining  the installation, it will inject a dummy x86 boot sector. If a
19       user subsequently attempts to boot via legacy BIOS firmware, instead of
20       UEFI,  a  message  will be printed (on both the primary serial port and
21       VGA display) indicating that UEFI is required.
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OPTIONS

24          • --boot-stub FILE-PATH
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26            Override the default file path identifying  the  precompiled  boot
27            stub binary that will be injected
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29          • --message FILE-PATH
30
31            Override the default message text that is printed when the instal‐
32            lation is booted under legacy BIOS firmware.
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34            The message file must fit within the remaining free space  of  the
35            boot  sector.  The dummy MBR and boot signature take 66 bytes, the
36            boot stub 21 bytes, and the  message  <NUL>  terminator  a  single
37            byte. This leaves 424 bytes for the text message.
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39            Note, the message file must use <CR><LF> line terminators.
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41          • --force
42
43            Normally  byebyebios  will  validate that the disk image specified
44            contains a valid GPT header signature before installing the  dummy
45            boot  sector.  This is a safety net against accidental overwriting
46            data in a file/device that is not a bootable OS image, should  the
47            wrong path be given.
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49            This  option  cause instalation of the boot sector even if the GPT
50            signature is not found. Be careful with use  of  this  option,  as
51            data  loss  will likely result if this tool is pointed to an inap‐
52            propriate file with the GPT check disabled.
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EXAMPLES

55   Injection post install
56       Create a disk image using virt-install(1) and inject a boot sector  af‐
57       ter installation is complete:
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59          $ virt-install \
60              --virt-type kvm \
61              --arch x86_64 \
62              --boot uefi \
63              --name demo \
64              --disk bus=virtio,format=raw,size=4 \
65              ...other args...
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67          $ byebyebios /var/lib/libvirt/images/demo.img
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69   Injection during install
70       Inject  a  boot sector as part of the installation process from an ana‐
71       conda(1) kickstart file (or equivalent):
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73          $ cat demo.ks
74          ...snip...
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76          ignoredisk --only-use=vda
77          clearpart --none --initlabel
78          part /boot/efi --fstype="efi" --ondisk=vda --size=1007 --fsoptions="umask=0077,shortname=winnt"
79          part / --fstype="ext4" --ondisk=vda --size=3087
80
81          ..snip...
82
83          %post
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85          byebyebios /dev/vda
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87          %end
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89   Customized warning message
90       To customize the warning  message  provide  a  custom  text  file  with
91       <CR><LF> line terminators:
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93          $ echo "Bye Bye BIOS" | figlet -f bubble | unix2dos > msg.txt
94          $ byebyebios --message msg.txt /var/lib/libvirt/images/demo.img
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BUGS

97       Please report all bugs you discover to the upstream repository:
98          https://gitlab.com/berrange/byebyebios
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100       Alternatively,  you may report bugs to your software distributor / ven‐
101       dor.
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AUTHORS

104       Daniel P. Berrangé
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COPYRIGHT

107       Copyright (C) 2023 Red Hat
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LICENSE

110       byebyebios is distributed under the terms of the MIT No Attribution li‐
111       cense.
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