fwup.conf

# Firmware configuration file for the Raspberry Pi 3

require-fwup-version="0.15.0"  # For the trim() call

#
# 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, "rpi3")
define(NERVES_FW_ARCHITECTURE, "arm")
define(NERVES_FW_AUTHOR, "The Nerves Team")

define(NERVES_FW_DEVPATH, "/dev/mmcblk0")
define(NERVES_FW_APPLICATION_PART0_DEVPATH, "/dev/mmcblk0p3") # Linux part number is 1-based
define(NERVES_FW_APPLICATION_PART0_FSTYPE, "ext4")
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 an MBR and the
# following 3 partitions:
#
# +----------------------------+
# | MBR                        |
# +----------------------------+
# | Firmware configuration data|
# | (formatted as uboot env)   |
# +----------------------------+
# | p0*: Boot A (FAT32)        |
# | zImage, bootcode.bin,      |
# | config.txt, etc.           |
# +----------------------------+
# | p0*: Boot B (FAT32)        |
# +----------------------------+
# | p1*: Rootfs A (squashfs)   |
# +----------------------------+
# | p1*: Rootfs B (squashfs)   |
# +----------------------------+
# | p2: Application (ext4)     |
# +----------------------------+
#
# The p0/p1 partition points to whichever of configurations A or B that is
# active.
#
# The image is sized to be less than 1 GB so that it fits on nearly any SDCard
# around. If you have a larger SDCard and need more space, feel free to bump
# the partition sizes below.

# The Raspberry Pi is incredibly picky on the partition sizes and in ways that
# I don't understand. Test changes one at a time to make sure that they boot.
# (Sizes are in 512 byte blocks)
define(UBOOT_ENV_OFFSET, 16)
define(UBOOT_ENV_COUNT, 16)  # 8 KB

define(BOOT_A_PART_OFFSET, 63)
define(BOOT_A_PART_COUNT, 38630)
define-eval(BOOT_B_PART_OFFSET, "${BOOT_A_PART_OFFSET} + ${BOOT_A_PART_COUNT}")
define(BOOT_B_PART_COUNT, ${BOOT_A_PART_COUNT})

# Let the rootfs have room to grow up to 128 MiB and align it to the nearest 1
# MB boundary
define(ROOTFS_A_PART_OFFSET, 77324)
define(ROOTFS_A_PART_COUNT, 289044)
define-eval(ROOTFS_B_PART_OFFSET, "${ROOTFS_A_PART_OFFSET} + ${ROOTFS_A_PART_COUNT}")
define(ROOTFS_B_PART_COUNT, ${ROOTFS_A_PART_COUNT})

# Application partition. This partition can occupy all of the remaining space.
# Size it to fit the destination.
define-eval(APP_PART_OFFSET, "${ROOTFS_B_PART_OFFSET} + ${ROOTFS_B_PART_COUNT}")
define(APP_PART_COUNT, 1048576)

# 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}

# File resources are listed in the order that they are included in the .fw file
# This is important, since this is the order that they're written on a firmware
# update due to the event driven nature of the update system.
file-resource bootcode.bin {
    host-path = "${NERVES_SYSTEM}/images/rpi-firmware/bootcode.bin"
}
file-resource fixup.dat {
    host-path = "${NERVES_SYSTEM}/images/rpi-firmware/fixup.dat"
}
file-resource start.elf {
    host-path = "${NERVES_SYSTEM}/images/rpi-firmware/start.elf"
}
file-resource config.txt {
    host-path = "${NERVES_SYSTEM}/images/config.txt"
}
file-resource cmdline.txt {
    host-path = "${NERVES_SYSTEM}/images/cmdline.txt"
}
file-resource zImage {
    host-path = "${NERVES_SYSTEM}/images/zImage"
}
file-resource bcm2710-rpi-3-b.dtb {
    host-path = "${NERVES_SYSTEM}/images/bcm2710-rpi-3-b.dtb"
}
file-resource bcm2710-rpi-cm3.dtb {
    host-path = "${NERVES_SYSTEM}/images/bcm2710-rpi-cm3.dtb"
}
file-resource w1-gpio-pullup.dtbo {
    host-path = "${NERVES_SYSTEM}/images/rpi-firmware/overlays/w1-gpio-pullup.dtbo"
}

file-resource rootfs.img {
    host-path = ${ROOTFS}

    # Error out if the rootfs size exceeds the partition size
    assert-size-lte = ${ROOTFS_A_PART_COUNT}
}

mbr mbr-a {
    partition 0 {
        block-offset = ${BOOT_A_PART_OFFSET}
        block-count = ${BOOT_A_PART_COUNT}
        type = 0xc # FAT32
        boot = true
    }
    partition 1 {
        block-offset = ${ROOTFS_A_PART_OFFSET}
        block-count = ${ROOTFS_A_PART_COUNT}
        type = 0x83 # Linux
    }
    partition 2 {
        block-offset = ${APP_PART_OFFSET}
        block-count = ${APP_PART_COUNT}
        type = 0x83 # Linux
    }
    # partition 3 is unused
}

mbr mbr-b {
    partition 0 {
        block-offset = ${BOOT_B_PART_OFFSET}
        block-count = ${BOOT_B_PART_COUNT}
        type = 0xc # FAT32
        boot = true
    }
    partition 1 {
        block-offset = ${ROOTFS_B_PART_OFFSET}
        block-count = ${ROOTFS_B_PART_COUNT}
        type = 0x83 # Linux
    }
    partition 2 {
        block-offset = ${APP_PART_OFFSET}
        block-count = ${APP_PART_COUNT}
        type = 0x83 # Linux
    }
    # partition 3 is unused
}

# 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}
}

# This firmware task writes everything to the destination media
task complete {
    # Only match if not mounted
    require-unmounted-destination = true

    on-init {
        mbr_write(mbr-a)

        uboot_clearenv(uboot-env)
        uboot_setenv(uboot-env, "nerves_fw_active", "a")
        uboot_setenv(uboot-env, "nerves_fw_devpath", ${NERVES_FW_DEVPATH})
        uboot_setenv(uboot-env, "a.nerves_fw_application_part0_devpath", ${NERVES_FW_APPLICATION_PART0_DEVPATH})
        uboot_setenv(uboot-env, "a.nerves_fw_application_part0_fstype", ${NERVES_FW_APPLICATION_PART0_FSTYPE})
        uboot_setenv(uboot-env, "a.nerves_fw_application_part0_target", ${NERVES_FW_APPLICATION_PART0_TARGET})
        uboot_setenv(uboot-env, "a.nerves_fw_product", ${NERVES_FW_PRODUCT})
        uboot_setenv(uboot-env, "a.nerves_fw_description", ${NERVES_FW_DESCRIPTION})
        uboot_setenv(uboot-env, "a.nerves_fw_version", ${NERVES_FW_VERSION})
        uboot_setenv(uboot-env, "a.nerves_fw_platform", ${NERVES_FW_PLATFORM})
        uboot_setenv(uboot-env, "a.nerves_fw_architecture", ${NERVES_FW_ARCHITECTURE})
        uboot_setenv(uboot-env, "a.nerves_fw_author", ${NERVES_FW_AUTHOR})
        uboot_setenv(uboot-env, "a.nerves_fw_vcs_identifier", ${NERVES_FW_VCS_IDENTIFIER})
        uboot_setenv(uboot-env, "a.nerves_fw_misc", ${NERVES_FW_MISC})

        fat_mkfs(${BOOT_A_PART_OFFSET}, ${BOOT_A_PART_COUNT})
        fat_setlabel(${BOOT_A_PART_OFFSET}, "BOOT-A")
        fat_mkdir(${BOOT_A_PART_OFFSET}, "overlays")
    }

    on-resource config.txt { fat_write(${BOOT_A_PART_OFFSET}, "config.txt") }
    on-resource cmdline.txt { fat_write(${BOOT_A_PART_OFFSET}, "cmdline.txt") }
    on-resource bootcode.bin { fat_write(${BOOT_A_PART_OFFSET}, "bootcode.bin") }
    on-resource start.elf { fat_write(${BOOT_A_PART_OFFSET}, "start.elf") }
    on-resource fixup.dat { fat_write(${BOOT_A_PART_OFFSET}, "fixup.dat") }
    on-resource zImage { fat_write(${BOOT_A_PART_OFFSET}, "zImage") }
    on-resource bcm2710-rpi-3-b.dtb { fat_write(${BOOT_A_PART_OFFSET}, "bcm2710-rpi-3-b.dtb") }
    on-resource bcm2710-rpi-cm3.dtb { fat_write(${BOOT_A_PART_OFFSET}, "bcm2710-rpi-cm3.dtb") }
    on-resource w1-gpio-pullup.dtbo { fat_write(${BOOT_A_PART_OFFSET}, "overlays/w1-gpio-pullup.dtbo") }

    on-resource rootfs.img {
        # write to the first rootfs partition
        raw_write(${ROOTFS_A_PART_OFFSET})
    }

    on-finish {
        # Clear out any old data in the B partition that might be mistaken for
        # a file system. This is mostly to avoid confusion in humans when
        # reprogramming SDCards with unknown contents.
        raw_memset(${BOOT_B_PART_OFFSET}, 256, 0xff)
        raw_memset(${ROOTFS_B_PART_OFFSET}, 256, 0xff)

        # Invalidate the application data partition so that it is guaranteed to
        # trigger the corrupt filesystem detection code on first boot and get
        # formatted. If this isn't done and an old SDCard is reused, the
        # application data could be in a weird state.
        raw_memset(${APP_PART_OFFSET}, 256, 0xff)
    }
}

task upgrade.a {
    # This task upgrades the A partition
    require-partition-offset(1, ${ROOTFS_B_PART_OFFSET})

    # Verify 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-init {
        info("Upgrading partition A")

        # Clear some firmware information just in case this update gets
        # interrupted midway. If this partition was bootable, it's not going to
        # be soon.
        uboot_unsetenv(uboot-env, "a.nerves_fw_version")
        uboot_unsetenv(uboot-env, "a.nerves_fw_platform")
        uboot_unsetenv(uboot-env, "a.nerves_fw_architecture")

        # Reset the previous contents of the A boot partition
        fat_mkfs(${BOOT_A_PART_OFFSET}, ${BOOT_A_PART_COUNT})
        fat_setlabel(${BOOT_A_PART_OFFSET}, "BOOT-A")
        fat_mkdir(${BOOT_A_PART_OFFSET}, "overlays")

        # Indicate that the entire partition can be cleared
        trim(${ROOTFS_A_PART_OFFSET}, ${ROOTFS_A_PART_COUNT})
    }

    # Write the new boot partition files and rootfs. The MBR still points
    # to the B partition, so an error or power failure during this part
    # won't hurt anything.
    on-resource config.txt { fat_write(${BOOT_A_PART_OFFSET}, "config.txt") }
    on-resource cmdline.txt { fat_write(${BOOT_A_PART_OFFSET}, "cmdline.txt") }
    on-resource bootcode.bin { fat_write(${BOOT_A_PART_OFFSET}, "bootcode.bin") }
    on-resource start.elf { fat_write(${BOOT_A_PART_OFFSET}, "start.elf") }
    on-resource fixup.dat { fat_write(${BOOT_A_PART_OFFSET}, "fixup.dat") }
    on-resource zImage { fat_write(${BOOT_A_PART_OFFSET}, "zImage") }
    on-resource bcm2710-rpi-3-b.dtb { fat_write(${BOOT_A_PART_OFFSET}, "bcm2710-rpi-3-b.dtb") }
    on-resource bcm2710-rpi-cm3.dtb { fat_write(${BOOT_A_PART_OFFSET}, "bcm2710-rpi-cm3.dtb") }
    on-resource w1-gpio-pullup.dtbo { fat_write(${BOOT_A_PART_OFFSET}, "overlays/w1-gpio-pullup.dtbo") }
    on-resource rootfs.img { raw_write(${ROOTFS_A_PART_OFFSET}) }

    on-finish {
        # Update firmware metadata
        uboot_setenv(uboot-env, "a.nerves_fw_application_part0_devpath", ${NERVES_FW_APPLICATION_PART0_DEVPATH})
        uboot_setenv(uboot-env, "a.nerves_fw_application_part0_fstype", ${NERVES_FW_APPLICATION_PART0_FSTYPE})
        uboot_setenv(uboot-env, "a.nerves_fw_application_part0_target", ${NERVES_FW_APPLICATION_PART0_TARGET})
        uboot_setenv(uboot-env, "a.nerves_fw_product", ${NERVES_FW_PRODUCT})
        uboot_setenv(uboot-env, "a.nerves_fw_description", ${NERVES_FW_DESCRIPTION})
        uboot_setenv(uboot-env, "a.nerves_fw_version", ${NERVES_FW_VERSION})
        uboot_setenv(uboot-env, "a.nerves_fw_platform", ${NERVES_FW_PLATFORM})
        uboot_setenv(uboot-env, "a.nerves_fw_architecture", ${NERVES_FW_ARCHITECTURE})
        uboot_setenv(uboot-env, "a.nerves_fw_author", ${NERVES_FW_AUTHOR})
        uboot_setenv(uboot-env, "a.nerves_fw_vcs_identifier", ${NERVES_FW_VCS_IDENTIFIER})
        uboot_setenv(uboot-env, "a.nerves_fw_misc", ${NERVES_FW_MISC})

	# Switch over to boot the new firmware
        uboot_setenv(uboot-env, "nerves_fw_active", "a")
        mbr_write(mbr-a)
    }

    on-error {
    }
}

task upgrade.b {
    # This task upgrades the B partition
    require-partition-offset(1, ${ROOTFS_A_PART_OFFSET})

    # Verify 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-init {
        info("Upgrading partition B")

        # Clear some firmware information just in case this update gets
        # interrupted midway.
        uboot_unsetenv(uboot-env, "b.nerves_fw_version")
        uboot_unsetenv(uboot-env, "b.nerves_fw_platform")
        uboot_unsetenv(uboot-env, "b.nerves_fw_architecture")

        # Reset the previous contents of the B boot partition
        fat_mkfs(${BOOT_B_PART_OFFSET}, ${BOOT_B_PART_COUNT})
        fat_setlabel(${BOOT_B_PART_OFFSET}, "BOOT-B")
        fat_mkdir(${BOOT_B_PART_OFFSET}, "overlays")

        trim(${ROOTFS_B_PART_OFFSET}, ${ROOTFS_B_PART_COUNT})
    }

    # Write the new boot partition files and rootfs. The MBR still points
    # to the A partition, so an error or power failure during this part
    # won't hurt anything.
    on-resource config.txt { fat_write(${BOOT_B_PART_OFFSET}, "config.txt") }
    on-resource cmdline.txt { fat_write(${BOOT_B_PART_OFFSET}, "cmdline.txt") }
    on-resource bootcode.bin { fat_write(${BOOT_B_PART_OFFSET}, "bootcode.bin") }
    on-resource start.elf { fat_write(${BOOT_B_PART_OFFSET}, "start.elf") }
    on-resource fixup.dat { fat_write(${BOOT_B_PART_OFFSET}, "fixup.dat") }
    on-resource zImage { fat_write(${BOOT_B_PART_OFFSET}, "zImage") }
    on-resource bcm2710-rpi-3-b.dtb { fat_write(${BOOT_B_PART_OFFSET}, "bcm2710-rpi-3-b.dtb") }
    on-resource bcm2710-rpi-cm3.dtb { fat_write(${BOOT_B_PART_OFFSET}, "bcm2710-rpi-cm3.dtb") }
    on-resource w1-gpio-pullup.dtbo { fat_write(${BOOT_B_PART_OFFSET}, "overlays/w1-gpio-pullup.dtbo") }
    on-resource rootfs.img { raw_write(${ROOTFS_B_PART_OFFSET}) }

    on-finish {
        # Update firmware metadata
        uboot_setenv(uboot-env, "b.nerves_fw_application_part0_devpath", ${NERVES_FW_APPLICATION_PART0_DEVPATH})
        uboot_setenv(uboot-env, "b.nerves_fw_application_part0_fstype", ${NERVES_FW_APPLICATION_PART0_FSTYPE})
        uboot_setenv(uboot-env, "b.nerves_fw_application_part0_target", ${NERVES_FW_APPLICATION_PART0_TARGET})
        uboot_setenv(uboot-env, "b.nerves_fw_product", ${NERVES_FW_PRODUCT})
        uboot_setenv(uboot-env, "b.nerves_fw_description", ${NERVES_FW_DESCRIPTION})
        uboot_setenv(uboot-env, "b.nerves_fw_version", ${NERVES_FW_VERSION})
        uboot_setenv(uboot-env, "b.nerves_fw_platform", ${NERVES_FW_PLATFORM})
        uboot_setenv(uboot-env, "b.nerves_fw_architecture", ${NERVES_FW_ARCHITECTURE})
        uboot_setenv(uboot-env, "b.nerves_fw_author", ${NERVES_FW_AUTHOR})
        uboot_setenv(uboot-env, "b.nerves_fw_vcs_identifier", ${NERVES_FW_VCS_IDENTIFIER})
        uboot_setenv(uboot-env, "b.nerves_fw_misc", ${NERVES_FW_MISC})

	# Switch over to boot the new firmware
        uboot_setenv(uboot-env, "nerves_fw_active", "b")
        mbr_write(mbr-b)
    }

    on-error {
    }
}

task upgrade.unexpected {
    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 {
        error("Please check the media being upgraded. It doesn't look like either the A or B partitions are active.")
    }
}

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