Provide some developer documentation on the priority feature for global
bootmeths.
Series-changes: 2
- Add a bit more detail suggested by Heinrich
Series-to: concept
Series-cc: heinrich
Cover-letter:
boot: Support priority for global bootmeths
At present global bootmeths always run first, before all other
bootmeths. Optimisations in the code take advantage of this, putting
them at the end, so they can be used once and then forgotten.
In some cases it is useful to run global bootmeths later in the boot.
For example, the EFI-bootmgr bootmeth may itself scan devices and the
network, so running it first can hold up the boot significantly for
boards not actually relying on EFI-bootmgr to boot.
This series introduces a new field in global bootmeths which indicates
the priority, using the same scheme as is used with bootdev hunters.
Thus it is possible to insert the EFI-bootmgr bootmeth just before the
hunter for network bootdevs is invoked.
Despite the simplicity of the concept and the relatively small series,
this is a fairly significant enhancement. It is also quite tricky to
implement, largely due to the way the original code was written, with
global bootmeths being a small, size-optimised add-on to the original
bootstd implementation.
For now we only allow each global bootmeth to run at most once, but this
implementation is written in a way that we could relax that if needed.
Then the bootmeth itself could decide whether to run at any particular
point in the bootflow iteration.
Size growth is about 390 bytes on Thumb2 (e.g. firefly-rk3288) if
CONFIG_BOOTMETH_GLOBAL is enabled, which it normally is. With that
disabled (which saves about 4K on the same platform), there is no
growth.
END
Signed-off-by: Simon Glass <sjg@chromium.org>
Series-links: 1:41
Series-version: 2
This existing function does not have any context associated with it.
Rename it so that fs_read() can be used for the new FS uclass.
Signed-off-by: Simon Glass <sjg@chromium.org>
Any 'bootable' flag in a DOS partition causes boostd to only scan
bootable partitions for that media. This can mean that extlinux.conf
files on the root disk are missed.
Put this logic behind a flag and update the documentation.
For now, the flag is enabled, to preserve existing behaviour. Future
work may provide a command (or some other mechanism) to control this.
Signed-off-by: Simon Glass <sjg@chromium.org>
This makes a start on dealing with images loaded outside the context of
bootstd. For now, it just records these images. They can be listed using
the 'bootstd images' command.
Often, very little is known about these images, but future work could
perhaps use the filename or contents to detect the type.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add a new 'bootstd images' command, which lists the images which have
been loaded.
Update some existing tests to use it. Provide some documentation about
images in general and this command in particular.
Use a more realistic kernel command-line to make the test easier to
follow.
Signed-off-by: Simon Glass <sjg@chromium.org>
We have previously added logic to allow a "fallback" option to be
specified in the extlinux configuration. Provide a command that allows
us to set this as the preferred default option when booting.
Combined with the bootcount functionality, this allows the "altbootcmd"
to provide a means of falling back to a previously known good state
after a failed update. For example, if "bootcmd" is set to:
bootflow scan -lb
We would set "altbootcmd" to:
bootmeth set extlinux fallback 1; bootflow scan -lb
Causing the boot process to boot from the fallback option.
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
Add documentation for the sandbox bootmeth.
Fix up the compatible string to drop the 'extlinux' part, which is not
relevant to this bootmeth.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Add documentation for the qfw bootmeth.
Fix up the compatible string to drop the 'extlinux' part, which is not
relevant to this bootmeth.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
