fwup-revert.conf

# Revert firmware for onlogic_cl210
#
# To use:
#   1. Run `fwup -c -f fwup-revert.conf -o revert.fw` and copy revert.fw to
#      the device. This is done automatically as part of the Nerves system
#      build process. The file is stored in `/usr/share/fwup/revert.fw`.
#   2. On the device, run `fwup -t revert revert.fw -d $NERVES_FW_DEVPATH`. If
#      it succeeds, reboot. If not, then it's possible that there isn't a previous
#      firmware or the metadata about what's stored where is corrupt or out of
#      sync.
#
# It is critical that this is kept in sync with the main fwup.conf.

require-fwup-version="1.4.0"

#
# Firmware metadata
#

# All of these can be overriden using environment variables of the same name.
#
#  Run 'fwup -m' to query values in a .fw file.
#  Use 'fw_printenv' to query values on the target.
#
# These are used by Nerves libraries to introspect.
define(NERVES_FW_PRODUCT, "Nerves Firmware")
define(NERVES_FW_DESCRIPTION, "")
define(NERVES_FW_VERSION, "${NERVES_SDK_VERSION}")
define(NERVES_FW_PLATFORM, "onlogic_cl210")
define(NERVES_FW_ARCHITECTURE, "x86_64")
define(NERVES_FW_AUTHOR, "Very")

# /dev/rootdisk* paths are provided by erlinit to refer to the disk and partitions
# on whatever drive provides the rootfs.
define(NERVES_FW_DEVPATH, "/dev/rootdisk0")
define(NERVES_FW_APPLICATION_PART0_DEVPATH, "/dev/rootdisk0p4") # Linux part number is 1-based
define(NERVES_FW_APPLICATION_PART0_FSTYPE, "f2fs")
define(NERVES_FW_APPLICATION_PART0_TARGET, "/root")

# Default paths if not specified via the commandline
define(ROOTFS, "${NERVES_SYSTEM}/images/rootfs.squashfs")

# This configuration file will create an image that has the following
# partitions:
#
# +-------------------------------+
# | GPT                           |
# +-------------------------------+
# | Firmware configuration data   |
# | (formatted as uboot env)      |
# +-------------------------------+
# | p0*: Kernel/EFI A (Readonly FAT32) |
# | /EFI/NERVES/bzImage.efi       |
# | /EFI/NERVES/nerves_initramfs  |
# +-------------------------------+
# | p0*: Kernel/EFI B (Readonly FAT32) |
# +-------------------------------+
# | p1*: Rootfs A (squashfs)      |
# +-------------------------------+
# | p1*: Rootfs B (squashfs)      |
# +-------------------------------+
# | p3: Application (f2fs)        |
# +-------------------------------+

define(EFI_TYPE, "c12a7328-f81f-11d2-ba4b-00a0c93ec93b")
define(LINUX_ROOT_X86_64_TYPE, "4f68bce3-e8cd-4db1-96e7-fbcaf984b709")
define(LINUX_FILESYSTEM_DATA_TYPE, "0fc63daf-8483-4772-8e79-3d69d8477de4")

define(NERVES_SYSTEM_DISK_UUID, "c8decfc3-2f19-4b05-85fc-d86d61e0d48c")
define(NERVES_SYSTEM_EFI_PART_UUID, "b8f50e97-5fe1-4e21-9b59-9bc6cdf86008")
define(NERVES_SYSTEM_ROOTFS_PART_UUID, "2f53b205-337c-4129-8826-2b2368598d6a")
define(NERVES_SYSTEM_APP_PART_UUID, "1b238cbb-7974-4e14-b34e-b9766fb10f8b")

define(UBOOT_ENV_OFFSET, 2048)
define(UBOOT_ENV_COUNT, 256)  # 128 KB

# The EFI partition contains the bootloader configuration
# 16 MB should be plenty for now.
define(EFI_A_PART_OFFSET, 4096)
define(EFI_A_PART_COUNT, 32768)
define-eval(EFI_B_PART_OFFSET, "${EFI_A_PART_OFFSET} + ${EFI_A_PART_COUNT}")
define(EFI_B_PART_COUNT, ${EFI_A_PART_COUNT})

# Let the rootfs have room to grow up to 512 MiB
define-eval(ROOTFS_A_PART_OFFSET, "${EFI_B_PART_OFFSET} + ${EFI_B_PART_COUNT}")
define(ROOTFS_A_PART_COUNT, 1048576)
define-eval(ROOTFS_B_PART_OFFSET, "${ROOTFS_A_PART_OFFSET} + ${ROOTFS_A_PART_COUNT}")
define(ROOTFS_B_PART_COUNT, ${ROOTFS_A_PART_COUNT})

# Application data partition (4 GiB). This can be enlarged
# to fill the entire volume.
define-eval(APP_PART_OFFSET, "${ROOTFS_B_PART_OFFSET} + ${ROOTFS_B_PART_COUNT}")
define(APP_PART_COUNT, 8388608)

# Firmware archive metadata
meta-product = ${NERVES_FW_PRODUCT}
meta-description = ${NERVES_FW_DESCRIPTION}
meta-version = ${NERVES_FW_VERSION}
meta-platform = ${NERVES_FW_PLATFORM}
meta-architecture = ${NERVES_FW_ARCHITECTURE}
meta-author = ${NERVES_FW_AUTHOR}
meta-vcs-identifier = ${NERVES_FW_VCS_IDENTIFIER}
meta-misc = ${NERVES_FW_MISC}

gpt gpt-a {
    guid = ${NERVES_SYSTEM_DISK_UUID}

    partition 0 {
        block-offset = ${EFI_A_PART_OFFSET}
        block-count = ${EFI_A_PART_COUNT}
        type = ${EFI_TYPE}
        guid = ${NERVES_SYSTEM_EFI_PART_UUID}
        name = "EFI Partition"
    }
    partition 1 {
        block-offset = ${ROOTFS_A_PART_OFFSET}
        block-count = ${ROOTFS_A_PART_COUNT}
        type = ${LINUX_ROOT_X86_64_TYPE}
        guid = ${NERVES_SYSTEM_ROOTFS_PART_UUID}
        name = "RootFS A Partition"
    }
    partition 3 {
        block-offset = ${APP_PART_OFFSET}
        block-count = ${APP_PART_COUNT}
        type = ${LINUX_FILESYSTEM_DATA_TYPE}
        guid = ${NERVES_SYSTEM_APP_PART_UUID}
        name = "Application Data Partition"
        expand = true
    }
}

gpt gpt-b {
    guid = ${NERVES_SYSTEM_DISK_UUID}

    partition 0 {
        block-offset = ${EFI_B_PART_OFFSET}
        block-count = ${EFI_B_PART_COUNT}
        type = ${EFI_TYPE}
        guid = ${NERVES_SYSTEM_EFI_PART_UUID}
        name = "EFI Partition"
    }
    partition 1 {
        block-offset = ${ROOTFS_B_PART_OFFSET}
        block-count = ${ROOTFS_B_PART_COUNT}
        type = ${LINUX_ROOT_X86_64_TYPE}
        guid = ${NERVES_SYSTEM_ROOTFS_PART_UUID}
        name = "RootFS B Partition"
    }
    partition 3 {
        block-offset = ${APP_PART_OFFSET}
        block-count = ${APP_PART_COUNT}
        type = ${LINUX_FILESYSTEM_DATA_TYPE}
        guid = ${NERVES_SYSTEM_APP_PART_UUID}
        name = "Application Data Partition"
        expand = true
    }
}

# Location where installed firmware information is stored.
# While this is called "u-boot", u-boot isn't involved in this
# setup. It just provides a convenient key/value store format.
uboot-environment uboot-env {
    block-offset = ${UBOOT_ENV_OFFSET}
    block-count = ${UBOOT_ENV_COUNT}
}

task revert.a {
    # This task reverts to the A partition, so check that we're running on B
    require-uboot-variable(uboot-env, "nerves_fw_active", "b")

    # Verify that partition A has the expected platform/architecture
    require-uboot-variable(uboot-env, "a.nerves_fw_platform", "${NERVES_FW_PLATFORM}")
    require-uboot-variable(uboot-env, "a.nerves_fw_architecture", "${NERVES_FW_ARCHITECTURE}")

    on-finish {
      info("Reverting to partition A")

      uboot_setenv(uboot-env, "nerves_fw_active", "a")
      uboot_setenv(uboot-env, "nerves_fw_validated", "1")
      gpt_write(gpt-a)
    }
}

task revert.b {
    # This task reverts to the B partition, so check that we're running on A
    require-uboot-variable(uboot-env, "nerves_fw_active", "a")

    # Verify that partition B has the expected platform/architecture
    require-uboot-variable(uboot-env, "b.nerves_fw_platform", "${NERVES_FW_PLATFORM}")
    require-uboot-variable(uboot-env, "b.nerves_fw_architecture", "${NERVES_FW_ARCHITECTURE}")

    on-finish {
      info("Reverting to partition B")

      # Switch over
      uboot_setenv(uboot-env, "nerves_fw_active", "b")
      uboot_setenv(uboot-env, "nerves_fw_validated", "1")
      gpt_write(gpt-b)
    }
}

task revert.unexpected.a {
    require-uboot-variable(uboot-env, "a.nerves_fw_platform", "${NERVES_FW_PLATFORM}")
    require-uboot-variable(uboot-env, "a.nerves_fw_architecture", "${NERVES_FW_ARCHITECTURE}")
    on-init {
        # Case where A is good, and the desire is to go to B.
        error("It doesn't look like there's anything to revert to in partition B.")
    }
}
task revert.unexpected.b {
    require-uboot-variable(uboot-env, "b.nerves_fw_platform", "${NERVES_FW_PLATFORM}")
    require-uboot-variable(uboot-env, "b.nerves_fw_architecture", "${NERVES_FW_ARCHITECTURE}")
    on-init {
        # Case where B is good, and the desire is to go to A.
        error("It doesn't look like there's anything to revert to in partition A.")
    }
}

task revert.wrongplatform {
    on-init {
        error("Expecting platform=${NERVES_FW_PLATFORM} and architecture=${NERVES_FW_ARCHITECTURE}")
    }
}

# Run "fwup /usr/share/fwup/revert.fw -t status -d /dev/rootdisk0 -q -U" to check the status.
task status.aa {
    require-path-on-device("/", "/dev/rootdisk0p2")
    require-uboot-variable(uboot-env, "nerves_fw_active", "a")
    on-init { info("a") }
}
task status.ab {
    require-path-on-device("/", "/dev/rootdisk0p2")
    require-uboot-variable(uboot-env, "nerves_fw_active", "b")
    on-init { info("a->b") }
}
task status.bb {
    require-path-on-device("/", "/dev/rootdisk0p3")
    require-uboot-variable(uboot-env, "nerves_fw_active", "b")
    on-init { info("b") }
}
task status.ba {
    require-path-on-device("/", "/dev/rootdisk0p3")
    require-uboot-variable(uboot-env, "nerves_fw_active", "a")
    on-init { info("b->a") }
}
task status.fail {
    on-init { error("fail") }
}