d9152ea75e
This provides a basic prototype for boot control. Some documentation is in boot/bootctl/README.rst
94 lines
2.3 KiB
ReStructuredText
94 lines
2.3 KiB
ReStructuredText
bootctl - Boot Schema
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=====================
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Introduction
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------------
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This is a very basic prototype which aims to show some of the concepts behind
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the 'boot schema' idea and how they can be implemented in practice.
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Please see the FO215 document for details on the schema.
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Features
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--------
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Very, very few features are supported:
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- basic menu
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- finding OSes for the menu (only extlinux.conf and EFI are supported)
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- measurement of images using a TPM
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Running on QEMU
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---------------
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To run this, first create an image with Ubuntu 2024.04. This script can help
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but you will need to edit some variables at the top (imagedir and mnt) or pass
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these vars into the script.
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This runs the installer:
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./scripts/build-qemu.sh -a x86 -r -k -d root.img -R 24.04
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Go through the full install and then reboot.
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Then run without the OS image:
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./scripts/build-qemu.sh -a x86 -r -k -d root.img
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Now you can install the u-boot-tools package so that an extlinux.conf file is
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created on the disk.
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When you reboot you should see a bootmenu with a few options.
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If you know U-Boot well you can probably run on sandbox
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Where is the schema?
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--------------------
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For now the schema is in `include/bootctl.dtsi` and is in devicetree format.
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We will likely use YAML for this, although it may be useful to then compile the
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YAML into devicetree in some cases.
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Where is the boot logic?
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------------------------
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See `boot/bootctl/bootctl.c` for the top-level program. It really just gets the
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logic driver and polls it until it either boots or gives up.
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The real logic is in `boot/bootctl/logic.c`. The `logic_start()` function sets
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things up, then `logic_poll()` actually manages finding things to boot and
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sending them to the UI.
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The data between `logic.c` and `ui.c` is a bit messy and can likely be tidied
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up.
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Source map
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----------
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boot/bootctl
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Directory containing the source for use with U-Boot
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cmd/
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Provides a very simple 'bootctl' command to start things up
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include/bootctl
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Include files for bootctl
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test/boot/bootctl
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A few very simple tests to give a flavour of how tests might work
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What about all the other patches related to expo? Please just ignore these. My
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original prototype was terribly ugly so I spent some time trying to clean it
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up.
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Comments
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--------
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Please send any and all comments and suggestions to me.
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--
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Simon Glass
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26-Mar-25
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