diff options
Diffstat (limited to 'man/systemd-boot.xml')
| -rw-r--r-- | man/systemd-boot.xml | 39 |
1 files changed, 17 insertions, 22 deletions
diff --git a/man/systemd-boot.xml b/man/systemd-boot.xml index 2e2a675ec2..6d99520036 100644 --- a/man/systemd-boot.xml +++ b/man/systemd-boot.xml @@ -436,28 +436,6 @@ </varlistentry> <varlistentry> - <term><varname>LoaderRandomSeed</varname></term> - - <listitem><para>A binary random seed <command>systemd-boot</command> may optionally pass to the - OS. This is a volatile EFI variable that is hashed at boot from the combination of a random seed - stored in the ESP (in <filename>/loader/random-seed</filename>) and a "system token" persistently - stored in the EFI variable <varname>LoaderSystemToken</varname> (see below). During early OS boot the - system manager reads this variable and passes it to the OS kernel's random pool, crediting the full - entropy it contains. This is an efficient way to ensure the system starts up with a fully initialized - kernel random pool — as early as the initrd phase. <command>systemd-boot</command> reads - the random seed from the ESP, combines it with the "system token", and both derives a new random seed - to update in-place the seed stored in the ESP, and the random seed to pass to the OS from it via - SHA256 hashing in counter mode. This ensures that different physical systems that boot the same - "golden" OS image — i.e. containing the same random seed file in the ESP — will still pass a - different random seed to the OS. It is made sure the random seed stored in the ESP is fully - overwritten before the OS is booted, to ensure different random seed data is used between subsequent - boots.</para> - - <para>See <ulink url="https://systemd.io/RANDOM_SEEDS">Random Seeds</ulink> for - further information.</para></listitem> - </varlistentry> - - <varlistentry> <term><varname>LoaderSystemToken</varname></term> <listitem><para>A binary random data field, that is used for generating the random seed to pass to @@ -526,6 +504,23 @@ </refsect1> <refsect1> + <title>Using systemd-boot in virtual machines.</title> + + <para>When using qemu with OVMF (UEFI Firmware for virtual machines) the <option>-kernel</option> switch + works not only for linux kernels, but for any EFI binary, including sd-boot and unified linux + kernels. Example command line for loading sd-boot on x64:</para> + + <para> + <command>qemu-system-x86_64 <replaceable>[ ... ]</replaceable> + -kernel /usr/lib/systemd/boot/efi/systemd-bootx64.efi</command> + </para> + + <para>systemd-boot will detect that it was started directly instead of being loaded from ESP and will + search for the ESP in that case, taking into account boot order information from the hypervisor (if + available).</para> + </refsect1> + + <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |