Firmware/Storage

Firmware commands that work with internal storage.

fs-update

The fs-update command has two variants; signed and unsigned.

signed

• triggered by four game key hold during startup,
• searches for fs.zip or fsN.zip where N is the model tag; this file must be present on boot media,
• verifies the signature in the .zip file,
• installs the .zd file to the internal storage, verifying the block hashes in the .zip file against the block data in the .zd file,
• reboots automatically on completion,

unsigned

• installs a .zd file to the internal storage, verifying the block hashes in the .zd file against the block data in the .zd file,
• does not require or use the .zip file,
• does not reboot on completion.

fs-update filename

fs-verify

• verifies internal storage against the signed install .zip file,

fs-verify filename

fs-save

• writes an .img file using the internal storage as source,
• is very slow, intended for diagnostic use only.

devalias fsdisk

• used before an fs-update, fs-verify, or fs-save chooses which storage device will be used,
• defaults to the internal storage,
• is typically with external SD card slot,

devalias fsdisk ext:0

To Be Merged

How to install a 2GB build on a 4GB or 8GB machine

• use fs-update to install the 2GB build,
• use fs-resize to resize the partition that holds the root filesystem,
• boot the build,
• use resize2fs /dev/mmcblk0p2 to resize the root filesystem to the new size of the partition.

An interim fix until <trac>10040</trac> is fixed.

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Recipes

How to make an image copy of internal storage

• determine the size of the internal storage, as shown by banner, usually 4GB or 8GB,
• choose a USB flash drive, USB hard drive, or SD card that is larger than the internal storage size,

• filesystems add some overhead, so it might not be possible for a 4GB USB flash drive to hold the 4GB internal storage of an XO,
• choose ext2 or FAT filesystems for best compatibility with Open Firmware,
• choose a filesystem that has no critical data on it already, unless you already have copies of the data,

• use the fs-save command to make the image copy, for example:

ok fs-save u:\os.img

The screen will fill with grey blocks, and these will turn red indicating progress.

The process is very slow, typically 15 minutes for 4GB to a USB HDD, or three hours over NFS over USB ethernet. Use Tiny Core Linux (XO-1.5) or olpc-rescue for a faster process.

The image can be used for diagnosis. It may be converted to .zd for use by fs-update using the zhashfs program included in olpc-os-builder.