Firmware/Storage/Formats

From OLPC
Jump to navigation Jump to search

Summary

Removable media includes USB Flash drives, USB hard drives, SD cards, microSD cards, USB optical drives and USB solid state drives.

Open Firmware relies on removable media for reflashing, developer keys, and installation of operating system.

To ensure best support for removable media on Open Firmware, use a combination of;

  • the Master Boot Record (MBR) partition table type,
  • one partition, and;
  • the FAT32 filesystem.

Details

There are three things to think about:

  • the partition table type,
  • the partitions,
  • the filesystem of the first partition.

Partition Table Type

The partition table type, or partition map scheme, is how the media is divided into partitions.

Supported types are:

  • Master Boot Record (MBR), also known as msdos,
  • GUID partition table (GPT), for up to date firmware only, otherwise please upgrade,
  • raw, where a supported filesystem begins at the first block,

You can check the partition table type using Disk Utility on Mac OS X, or gparted on Linux.

Partitions

Supported is one partition, or none at all.

Where there are multiple partitions, only the first partition is used for automatic features of the firmware. When using the firmware interactively, the subsequent partitions must be referred to explicitly.

You can check the number of partitions using Disk Utility on Mac OS X, or gparted on Linux.

Filesystem

A partition or the raw device is to be formatted with a filesystem.

Supported types are:

  • FAT16,
  • FAT32,
  • ext2,
  • ext3,
  • ext4,
  • ISO-9660.

Unsupported types are:

  • NTFS,
  • ExFAT,

Unsupported extensions are:

  • long file name support in FAT filesystems.

You can check the filesystem using Disk Utility on Mac OS X, or gparted on Linux. In Disk Utility the filesystem is the "Format".

Preparing a USB drive using Mac OS X

Warning: changing the partitioning on a USB Flash drive may slow it down.

  • start Disk Utility,
  • insert the USB drive,
  • identify it in the list of drives, and click on it,
  • click on the Partition tab,
  • change Partition Layout from "Current" to "1 Partition",
  • change Format from "Mac OS Extended (Journaled)" to "MS-DOS (FAT)",
  • click on Options... and select "Master Boot Record", then Ok,
  • click on Apply, and an "Are you sure" message will appear,
  • click on Partition, and wait a few seconds for activity to finish.

Preparing a USB drive using Linux

Warning: changing the partitioning on a USB Flash drive may slow it down.

  • start gparted,
  • insert the USB drive,
  • identify it in the list of drives, and click on it,
  • click on Device and Create Partition Table..., and a window will appear,
  • select msdos as the partition type and click on Apply,
  • click on New, and a "Create new partition" window will appear,
  • set the File system to fat32, then click on Add,
  • click on Apply.

Preparing a USB drive using Open Firmware

Warning: changing the partitioning on a USB Flash drive may slow it down. 

ok d# 2048 fat32-partition u
Retrieved from "http://wiki.laptop.org/mediawiki/index.php?title=Firmware/Storage/Formats&oldid=298151"