nerves_system_rpi0

# Firmware configuration file for the Raspberry Pi

# 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                        |
# +----------------------------+
# | p0*: Boot A (FAT32)        |
# | zImage, bootcode.bin,      |
# | config.txt, etc.           |
# +----------------------------+
# | p0*: Boot B (FAT32)        |
# +----------------------------+
# | p1*: Rootfs A (squashfs)   |
# +----------------------------+
# | p1*: Rootfs B (squashfs)   |
# +----------------------------+
# | p2: Application (FAT32)    |
# +----------------------------+
#
# 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(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 metadata
meta-product = "Nerves Firmware"
meta-description = ""
meta-version = ${NERVES_SDK_VERSION}
meta-platform = "rpi"
meta-architecture = "arm"
meta-author = "Frank Hunleth"

# 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 bcm2708-rpi-0-w.dtb {
    host-path = "${NERVES_SYSTEM}/images/bcm2708-rpi-0-w.dtb"
}
file-resource bcm2708-rpi-b-plus.dtb {
    host-path = "${NERVES_SYSTEM}/images/bcm2708-rpi-b-plus.dtb"
}
file-resource w1-gpio-pullup.dtbo {
    host-path = "${NERVES_SYSTEM}/images/rpi-firmware/overlays/w1-gpio-pullup.dtbo"
}
file-resource dwc2.dtbo {
    host-path = "${NERVES_SYSTEM}/images/rpi-firmware/overlays/dwc2.dtbo"
}
file-resource pi3-miniuart-bt.dtbo {
    host-path = "${NERVES_SYSTEM}/images/rpi-firmware/overlays/pi3-miniuart-bt.dtbo"
}

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

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 = 0xc # FAT32
    }
    # 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 = 0xc # FAT32
    }
    # partition 3 is unused
}

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

    # Everything that gets written can be verified on the fly.
    # This speeds things up, since we don't care about detecting
    # errors before data gets written.
    verify-on-the-fly = true

    on-init {
        mbr_write(mbr-a)

        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 bcm2708-rpi-0-w.dtb { fat_write(${BOOT_A_PART_OFFSET}, "bcm2708-rpi-0-w.dtb") }
    on-resource bcm2708-rpi-b-plus.dtb { fat_write(${BOOT_A_PART_OFFSET}, "bcm2708-rpi-b-plus.dtb") }
    on-resource w1-gpio-pullup.dtbo { fat_write(${BOOT_A_PART_OFFSET}, "overlays/w1-gpio-pullup.dtbo") }
    on-resource dwc2.dtbo { fat_write(${BOOT_A_PART_OFFSET}, "overlays/dwc2.dtbo") }
    on-resource pi3-miniuart-bt.dtbo { fat_write(${BOOT_A_PART_OFFSET}, "overlays/pi3-miniuart-bt.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(${BOOT_B_PART_OFFSET}, 8, 0xff)
        raw_memset(${ROOTFS_B_PART_OFFSET}, 8, 0xff)

        # Initialize a big partition for application data. This is done last so
        # that the boot partition can be written to completely before the first
        # write to this partition. Not skipping back and forth between FAT
        # filesystems saves a little time when programming the Flash.
        fat_mkfs(${APP_PART_OFFSET}, ${APP_PART_COUNT})
        fat_setlabel(${APP_PART_OFFSET}, "APPDATA")
    }
}

task upgrade.a {
    # This task upgrades the A partition
    require-partition1-offset = ${ROOTFS_B_PART_OFFSET}

    on-init {
        info("Upgrading the A partition")
        # 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")
    }

    # 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 bcm2708-rpi-0-w.dtb { fat_write(${BOOT_A_PART_OFFSET}, "bcm2708-rpi-0-w.dtb") }
    on-resource bcm2708-rpi-b-plus.dtb { fat_write(${BOOT_A_PART_OFFSET}, "bcm2708-rpi-b-plus.dtb") }
    on-resource w1-gpio-pullup.dtbo { fat_write(${BOOT_A_PART_OFFSET}, "overlays/w1-gpio-pullup.dtbo") }
    on-resource dwc2.dtbo { fat_write(${BOOT_A_PART_OFFSET}, "overlays/dwc2.dtbo") }
    on-resource pi3-miniuart-bt.dtbo { fat_write(${BOOT_A_PART_OFFSET}, "overlays/pi3-miniuart-bt.dtbo") }
    on-resource rootfs.img { raw_write(${ROOTFS_A_PART_OFFSET}) }

    on-finish {
	# Switch over to boot the new firmware
        mbr_write(mbr-a)
    }

    on-error {
    }
}

task upgrade.b {
    # This task upgrades the B partition
    require-partition1-offset = ${ROOTFS_A_PART_OFFSET}

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

    # 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 bcm2708-rpi-0-w.dtb { fat_write(${BOOT_B_PART_OFFSET}, "bcm2708-rpi-0-w.dtb") }
    on-resource bcm2708-rpi-b-plus.dtb { fat_write(${BOOT_B_PART_OFFSET}, "bcm2708-rpi-b-plus.dtb") }
    on-resource w1-gpio-pullup.dtbo { fat_write(${BOOT_B_PART_OFFSET}, "overlays/w1-gpio-pullup.dtbo") }
    on-resource dwc2.dtbo { fat_write(${BOOT_B_PART_OFFSET}, "overlays/dwc2.dtbo") }
    on-resource pi3-miniuart-bt.dtbo { fat_write(${BOOT_B_PART_OFFSET}, "overlays/pi3-miniuart-bt.dtbo") }
    on-resource rootfs.img { raw_write(${ROOTFS_B_PART_OFFSET}) }

    on-finish {
	# Switch over to boot the new firmware
        mbr_write(mbr-b)
    }

    on-error {
    }
}

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