My primary use case for this flag is to fix booting with UEFI firmware
which can have problems when mixed with KVM, adding kexec into the mix
doesn't help matters either. The current version of OVMF can boot from
virtio drives just fine so that is now enabled and KVM is disabled.
So the -s option can also mean sloooooooow but boots!
The new grub install script must be called after the image is unmounted
and the old bootloaders script doesn't need to touch grub at all. For
now we will continue to use the existing syslinux configs but
interpreted by grub. Beyond the grub menu flashing by during boot
everything should still be functionally equivalent.
This script replaces the standard grub-install tool to give us some more
control over what is going and ensure grub-install's auto-detection
magic doesn't make any incorrect choices. Also this script sets up a
loopback device and mounts the EFI partition in just the right way for
grub-bios-setup's auto-detection magic to work correctly.
I've chosen not to adapt disk_util to use partitioned loop devices to
make grub happy because ensuring loop devices get cleaned up properly
for the general case gets tricky and less robust.
The passing ROOT= as an environment variable to board wrapper scripts
doesn't work, the script unconditionally overrides it. This means so far
our packages.txt files have listed the contents of /build/amd64-usr
instead of the image. Fix this by calling equery directly instead.
Not currently used, this configuration which sets up grub to re-use the
syslinux configuration only works with recent git versions, not any
releases. Compatibility is also limited because the serial configuration
in syslinux must be duplicated in the grub config.
We don't need to do anything like manually install the MBR boot code
for grub but we do need to continue to expose the ESP partition as a
hybrid partition to support pvgrub.
Calling cgpt create when resizing zeros the MBR boot code. This worked
with the syslinux setup because the boot code was re-written. When not
using syslinux it is easier to just preserve the existing MBR instead.
Unlike SYSLINUX, GRUB2 does not recommend embedding itself in a FAT
filesystem. Instead GRUB2 prefers embedding in the space between the MBR
and first partition or using a dedicated partition that is safe from
tampering by fs utilities. In our case the space after the MBR is where
the GPT lives so we need to use the extra partition scheme instead.
The 64MB "BOOT-B" partition has never been used so we can replace it
with a 2MB partition which is more than enough for GRUB.
We have long since stopped installing anything to the /boot directory of
the root filesystem. Mount the ESP partition to /boot for consistancy
with the discoverable partition spec.
Normally GCC is installed in a way that allows installing multiple
versions and switching between them. Our production images do not need
this and additionally the only things from the GCC package that are
needed are the shared libraries. To ensure these libraries are *always*
locatable regardless of the presence of /etc/ld.so.conf and
/etc/ld.so.cache we can install those libraries to plain old /usr/lib.
The GCC packages don't have a built in way to do this but we can get
away with extracting the libraries directly from the binary package.
This is actually similar to what ChromeOS did with a few exceptions:
- We use a native GCC build instead of the cross toolchain
- The archive is properly extracted from the package instead of feeding
the package directly to tar and ignoring the resulting warnings.
As an added benefit switching from a blacklist to a whitelist ensures
that extra cruft does not slip through the cracks, saving 5-10MB.
Create profile as a real directory instead of a symlink to the board
root's configuration. Normally the board root does not modify this but
it is useful for build_image to use it to modify package.provided.
Normally Gentoo expects moving between major GCC releases to be a manual
step. In our case we want this to always be automatic, otherwise the GCC
version won't be switched at all.
Apparently expanding an empty string before a variable assignment forces
that assignment to be interpreted as a command instead. Instead of an
empty string use env as our sudo alternative when running as root.
Needed for portage 2.2. Sync URIs are included but not very useful yet
because portage only can do `git pull` but not `git clone`. An extra
helper script will be required to do the initial clone it seems.
Binary packages may be useful for re-installing a package with a
different INSTALL_MASK. Can be used to install debug symbols.
Instead of gluing in a special PROD_INSTALL_MASK for all images use
profiles to configure the differences between the base build root,
production images, and developer images. This offers much more
flexibility and is needed for providing a full dev environment in
developer images.
Using parallel_emerge has been disabled by default for all commands
except build_image for quite a while now, build_image kept it just
because it was still a bit faster than normal emerge. Keeping
parallel_emerge complicates future changes to build_image so it needs to
drop it entirely. Since that means nothing uses it by default we might
as well just rip out support for it entirely.
VHD was just for testing, raw is more useful for published images.
coreos-install will now be able to install working xen instances:
coreos-install -d /dev/xvda -o xen -c cloud-config.yml
Missed this in 7231b95a, the update zip should still be built when the
usr partition is extracted for generating updates but build_image itself
is not generating and signing the update.
The current generate_update function is now less useful, the important
part that we need is just the partition image now. Also by defaulting to
extracting the partition the old cors_generate_update which is still in
use by devserver can be removed entirely, devserver will just expect the
extracted partition image instead.
