bootloader

type BootFile struct {
	// Path is the path to the file in the filesystem or, if Snap
	// is set, the relative path inside the snap file.
	Path string
	// Snap contains the path to the snap file if a snap file is used.
	Snap string
	// Role is set to the role of the bootloader this boot file
	// originates from.
	Role Role
}

type Bootloader interface {
	// Return the value of the specified bootloader variable.
	GetBootVars(names ...string) (map[string]string, error)

	// Set the value of the specified bootloader variable.
	SetBootVars(values map[string]string) error

	// Name returns the bootloader name.
	Name() string

	// ConfigFile returns the name of the config file.
	ConfigFile() string

	// InstallBootConfig will try to install the boot config in the
	// given gadgetDir to rootdir. If no boot config for this bootloader
	// is found ok is false.
	InstallBootConfig(gadgetDir string, opts *Options) (ok bool, err error)

	// ExtractKernelAssets extracts kernel assets from the given kernel snap.
	ExtractKernelAssets(s snap.PlaceInfo, snapf snap.Container) error

	// RemoveKernelAssets removes the assets for the given kernel snap.
	RemoveKernelAssets(s snap.PlaceInfo) error
}

type ExtractedRecoveryKernelImageBootloader interface {
	Bootloader
	ExtractRecoveryKernelAssets(recoverySystemDir string, s snap.PlaceInfo, snapf snap.Container) error
}

type ExtractedRunKernelImageBootloader interface {
	Bootloader

	// EnableKernel enables the specified kernel on ubuntu-boot to be used
	// during normal boots. The specified kernel should already have been
	// extracted. This is usually implemented with a "kernel.efi" symlink
	// pointing to the extracted kernel image.
	EnableKernel(snap.PlaceInfo) error

	// EnableTryKernel enables the specified kernel on ubuntu-boot to be
	// tried by the bootloader on a reboot, to be used in conjunction with
	// setting "kernel_status" to "try". The specified kernel should already
	// have been extracted. This is usually implemented with a
	// "try-kernel.efi" symlink pointing to the extracted kernel image.
	EnableTryKernel(snap.PlaceInfo) error

	// Kernel returns the current enabled kernel on the bootloader, not
	// necessarily the kernel that was used to boot the current session, but the
	// kernel that is enabled to boot on "normal" boots.
	// If error is not nil, the first argument shall be non-nil.
	Kernel() (snap.PlaceInfo, error)

	// TryKernel returns the current enabled try-kernel on the bootloader, if
	// there is no such enabled try-kernel, then ErrNoTryKernelRef is returned.
	// If error is not nil, the first argument shall be non-nil.
	TryKernel() (snap.PlaceInfo, error)

	// DisableTryKernel disables the current enabled try-kernel on the
	// bootloader, if it exists. It does not need to return an error if the
	// enabled try-kernel does not exist or is in an inconsistent state before
	// disabling it, errors should only be returned when the implementation
	// fails to disable the try-kernel.
	DisableTryKernel() error
}

type ManagedAssetsBootloader interface {
	Bootloader

	// IsCurrentlyManaged returns true when the on disk boot assets are managed.
	IsCurrentlyManaged() (bool, error)
	// ManagedAssets returns a list of boot assets managed by the bootloader
	// in the boot filesystem.
	ManagedAssets() []string
	// UpdateBootConfig updates the boot config assets used by the bootloader.
	UpdateBootConfig(*Options) error
	// CommandLine returns the kernel command line composed of mode and
	// system arguments, built-in bootloader specific static arguments
	// corresponding to the on-disk boot asset edition, followed by any
	// extra arguments. The command line may be different when using a
	// recovery bootloader.
	CommandLine(modeArg, systemArg, extraArgs string) (string, error)
	// CandidateCommandLine is similar to CommandLine, but uses the current
	// edition of managed built-in boot assets as reference.
	CandidateCommandLine(modeArg, systemArg, extraArgs string) (string, error)
}

type Options struct {
	// PrepareImageTime indicates whether the booloader is being
	// used at prepare-image time, that means not on a runtime
	// system.
	PrepareImageTime bool

	// Role specifies to use the bootloader for the given role.
	Role Role

	// NoSlashBoot indicates to use the native layout of the
	// bootloader partition and not the /boot mount.
	// It applies only for RoleRunMode.
	// It is implied and ignored for RoleRecovery.
	// It is an error to set it for RoleSole.
	NoSlashBoot bool
}

type RecoveryAwareBootloader interface {
	Bootloader
	SetRecoverySystemEnv(recoverySystemDir string, values map[string]string) error
	GetRecoverySystemEnv(recoverySystemDir string, key string) (string, error)
}

type Role string

type TrustedAssetsBootloader interface {
	// TrustedAssets returns the list of relative paths to assets inside
	// the bootloader's rootdir that are measured in the boot process in the
	// order of loading during the boot.
	TrustedAssets() ([]string, error)

	// RecoveryBootChain returns the load chain for recovery modes.
	// It should be called on a RoleRecovery bootloader.
	RecoveryBootChain(kernelPath string) ([]BootFile, error)

	// BootChain returns the load chain for run mode.
	// It should be called on a RoleRecovery bootloader passing the
	// RoleRunMode bootloader.
	BootChain(runBl Bootloader, kernelPath string) ([]BootFile, error)
}