| # Changes from disk_layout_v2: |
| # * Introduce 128MB MINIOS-A and MINIOS-B on partitions 9 and 10, with |
| # 10 being set as last_partition. |
| # * Reduce OEM partition 8 from 16MB to 4MB. |
| # * Remove -no-exports from ROOTFS-A squashfs options. |
| # * Add powerwash data as partition 11. |
| # * Delete 2gb-rootfs, 2gb-rootfs-updatable, and 4gb-rootfs. |
| { |
| # See README.disk_layout. |
| "parent": "common_disk_layout.json", |
| |
| "metadata": { |
| "block_size": 512, |
| "fs_block_size": 4096, |
| "fs_align": "2 MiB" |
| }, |
| "layouts": { |
| # common is the standard layout template. |
| "common": [ |
| { |
| # MiniOS A partition. |
| "num": 9, |
| "label": "MINIOS-A", |
| "type": "minios", |
| "size": "128 MiB" |
| }, |
| { |
| # Unused partition, reserved for software slot C. |
| "num": 6, |
| "label": "KERN-C", |
| "type": "kernel" |
| }, |
| { |
| # Unused partition, reserved for software slot C. |
| "num": 7, |
| "label": "ROOT-C", |
| "type": "rootfs" |
| }, |
| { |
| # Board specific files, mostly unused. |
| "num": 8, |
| "label": "OEM", |
| "type": "data", |
| "size": "4 MiB", |
| "fs_format": "ext4", |
| "uuid": "random" |
| }, |
| { |
| # Used for Legacy Bios, and EFI Bios, not ChromeOS hardware. |
| "num": 12, |
| "label": "EFI-SYSTEM", |
| "type": "efi", |
| "fs_format": "vfat", |
| "size": "64 MiB", |
| "uuid": "clear" |
| }, |
| { |
| # Kernel for Slot A, no file system. |
| "num": 2, |
| "label": "KERN-A", |
| "type": "kernel", |
| "size": "32 MiB" |
| }, |
| { |
| # Slot A rootfs. Rootfs + extras must fit. |
| # FS size + Verity (64 * FS blocks) + Boot Cache (200M). |
| # Make sure that other layouts still have room for the |
| # extras, should you increase FS size. |
| # |
| # Note that updates will fail if the rootfs size |
| # shrinks. (crbug.com/192136) |
| # |
| # Note: fs_size is intentionally much lower than partition size. See |
| # note under "Rootfs size limitations" in README.disk_layout |
| # |
| # Changes to the offset of this partition may require |
| # changes in cros-signing/security_test_baselines/ |
| # ensure_secure_kernelparams.config to allow secure boot. |
| "num": 3, |
| "label": "ROOT-A", |
| "type": "rootfs", |
| "fs_format": "ext2", |
| "fs_options": { |
| "squashfs": "-noI -comp lzo -Xalgorithm lzo1x_999 -Xcompression-level 9", |
| "btrfs": "skinny-metadata" |
| }, |
| "size": "4096 MiB", |
| "fs_size": "2300 MiB", |
| "uuid": "clear" |
| }, |
| { |
| # Kernel for Slot B, no file system. |
| "num": 4, |
| "label": "KERN-B", |
| "type": "kernel", |
| "size": "32 MiB" |
| }, |
| { |
| # Slot B rootfs. Must match Root A in size for normal |
| # updates. Will contain copy of Root A after install, and |
| # contain new rootfs's after runtime updates. |
| "num": 5, |
| "label": "ROOT-B", |
| "type": "rootfs", |
| "size": "4096 MiB" |
| }, |
| { |
| # Powerwash data, including rollback data. |
| "num": 11, |
| "label": "POWERWASH-DATA", |
| "type": "data", |
| "size": "4 MiB", |
| "uuid": "random" |
| }, |
| { |
| # User data, fills all remaining space on drive. |
| "num": 1, |
| "label": "STATE", |
| "type": "data", |
| "fs_format": "ext4", |
| "size": "4 GiB", |
| "features": ["expand"], |
| "uuid": "random" |
| }, |
| { |
| # MiniOS B partition. |
| "num": 10, |
| "label": "MINIOS-B", |
| "type": "minios", |
| "size": "128 MiB", |
| # Places partition at the end of disk. |
| "features": ["last_partition"] |
| } |
| ], |
| # Used for installs on main device. By default, same as 'common'. |
| "base": [ |
| ], |
| # Used for bootable USB installs (not recovery). |
| "usb": [ |
| { |
| "num": 3, |
| "size": "2400 MiB" |
| }, |
| { |
| "num": 5, |
| "size": "2 MiB" |
| }, |
| { |
| # MINIOS-B partitions are not filled with anything on USB images. |
| "num": 10, |
| "size": "2 MiB", |
| "type": "reserved" |
| } |
| ], |
| # Used for factory install images. |
| "factory_install": [ |
| { |
| "num": 3, |
| "size": "420 MiB", |
| "fs_size": "400 MiB" |
| }, |
| { |
| "num": 5, |
| "size": "2 MiB" |
| }, |
| { |
| "num": 1, |
| "size": "140 MiB" |
| }, |
| { |
| "num": 10, |
| "size": "2 MiB", |
| "type": "reserved" |
| } |
| ], |
| "recovery": [ |
| { |
| # Kernel for Slot A, no file system. |
| # Make the partition as large as the firmware supports so we can boot |
| # larger recovery kernels. The kernel won't actually be this large. |
| "num": 2, |
| "size": "512 MiB" |
| }, |
| { |
| # Shrunken rootfs partition to support smaller USB sticks, |
| # and smaller recovery downloads. |
| # Installation will expand this to size from base. |
| # The offset to the beginning of this partition, and the FS |
| # size must match base exactly to allow secure boot. |
| "num": 3, |
| "size": "2400 MiB" |
| }, |
| { |
| # Slot B rootfs, unused on USB, but pad to 2M. |
| # Installation will expand this to size from base. |
| "num": 5, |
| "size": "2 MiB" |
| }, |
| { |
| # Stateful on recovery is dynamically resized larger. |
| "num": 1, |
| "size": "2 MiB" |
| }, |
| { |
| "num": 10, |
| "size": "2 MiB", |
| "type": "reserved" |
| } |
| ], |
| # Huge rootfs, suitable for VM only images, should not be used |
| # for actual hardware devices. |
| "16gb-rootfs": [ |
| { |
| "num": 3, |
| "size": "16384 MiB", |
| "fs_size": "16000 MiB" |
| }, |
| { |
| "num": 5, |
| "size": "2 MiB" |
| }, |
| { |
| "num": 10, |
| "size": "2 MiB", |
| "type": "reserved" |
| } |
| ] |
| } |
| } |
