Files
snapd/boot/debug.go
2021-10-01 15:31:17 +02:00

139 lines
3.5 KiB
Go

// -*- Mode: Go; indent-tabs-mode: t -*-
/*
* Copyright (C) 2019 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
package boot
import (
"fmt"
"io"
"strings"
"github.com/snapcore/snapd/bootloader"
"github.com/snapcore/snapd/dirs"
"github.com/snapcore/snapd/osutil"
)
// DebugDumpBootVars writes a dump of the snapd bootvars to the given writer
func DebugDumpBootVars(w io.Writer, dir string, uc20 bool) error {
opts := &bootloader.Options{
NoSlashBoot: dir != "" && dir != "/",
}
switch dir {
// is it any of the well-known UC20 boot partition mount locations?
case InitramfsUbuntuBootDir:
opts.Role = bootloader.RoleRunMode
uc20 = true
case InitramfsUbuntuSeedDir:
opts.Role = bootloader.RoleRecovery
uc20 = true
}
if !opts.NoSlashBoot && !uc20 {
// this may still be a UC20 system
if osutil.FileExists(dirs.SnapModeenvFile) {
uc20 = true
}
}
allKeys := []string{
"snap_mode",
"snap_core",
"snap_try_core",
"snap_kernel",
"snap_try_kernel",
}
if uc20 {
if !opts.NoSlashBoot {
// no root directory set, default to run mode
opts.Role = bootloader.RoleRunMode
}
// keys relevant to all uc20 bootloader implementations
allKeys = []string{
"snapd_recovery_mode",
"snapd_recovery_system",
"snapd_recovery_kernel",
"snap_kernel",
"snap_try_kernel",
"kernel_status",
"recovery_system_status",
"try_recovery_system",
"snapd_good_recovery_systems",
"snapd_extra_cmdline_args",
"snapd_full_cmdline_args",
}
}
bloader, err := bootloader.Find(dir, opts)
if err != nil {
return err
}
bootVars, err := bloader.GetBootVars(allKeys...)
if err != nil {
return err
}
for _, k := range allKeys {
fmt.Fprintf(w, "%s=%s\n", k, bootVars[k])
}
return nil
}
// DebugSetBootVars is a debug helper that takes a list of <var>=<value> entries
// and sets them for the configured bootloader.
func DebugSetBootVars(dir string, recoveryBootloader bool, varEqVal []string) error {
opts := &bootloader.Options{
NoSlashBoot: dir != "" && dir != "/",
}
if opts.NoSlashBoot || osutil.FileExists(dirs.SnapModeenvFile) {
// implied UC20 bootloader
opts.Role = bootloader.RoleRunMode
}
// try some well known UC20 root dirs
switch dir {
case InitramfsUbuntuBootDir:
if recoveryBootloader {
return fmt.Errorf("cannot use run bootloader root-dir with a recovery flag")
}
opts.Role = bootloader.RoleRunMode
case InitramfsUbuntuSeedDir:
opts.Role = bootloader.RoleRecovery
}
if recoveryBootloader {
// UC20 recovery bootloader
opts.Role = bootloader.RoleRecovery
if !opts.NoSlashBoot {
// no root dir was provided, use the default one for a
// recovery bootloader
dir = InitramfsUbuntuSeedDir
}
}
bloader, err := bootloader.Find(dir, opts)
if err != nil {
return err
}
toSet := map[string]string{}
for _, req := range varEqVal {
split := strings.SplitN(req, "=", 2)
if len(split) != 2 {
return fmt.Errorf("incorrect setting %q", varEqVal)
}
toSet[split[0]] = split[1]
}
return bloader.SetBootVars(toSet)
}