Wishlist/LiveUSB distro
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Contents |
Introduction
An openmoko device could act as the perfect geeky swiss knive: go anywhere with your Linux desktop and tools.
Similar functionality can be found in the Wizpy portable media player
When the openmoko device is in mass storage mode, a host computer should be able to boot on it, presenting a grub menu offering to boot into several images / partitions (payloads) on the transflash: memtest, UBCD (the ultimate boot cd), a lightweight security oriented livecd distro, you name it...
It's sometimes called Live USB: from Wikipedia LiveUSB definition, A live USB is a USB flash drive containing a full operating system which can be booted from. Live USBs are closely related to Live CDs, and are sometimes used interchangeably. Like Live CDs, Live USBs can be used for system administration, data recovery, or the testing of operating system distributions without committing to a permanent installation on the local hard drive. Many of the smaller Linux distributions can also be used from a USB flash drive.
Usually, all you need for this with an USB storage device (flash USB stick or external drive) is a partition, flagged "bootable" (see fdisk), containing a boot loader (say grub). But the problem is that specifications vary between motherboards, so there are variants and mandatory requirements to define (here would be a good idea), so that one can optimize/maximize the compatibility.
USB Booting
From DSL Wiki:
Older computer BIOS usually do not support direct booting from a USB device. Around 2001, PC motherboard manufacturers started to add USB boot support.
There are two common BIOS methods for direct USB booting:
- One method is called the "USBHDD" method and it is used to support the booting of standard USB mass storage devices that are configured like a normal PC hard drive.
- The other method is called the "USBZIP" method and it supports booting from a USB storage device that behaves like the original IOMEGA ZIP drive with USB support.
Most computers (just about all Dells, for example) made today have a BIOS that supports the USBHDD method so I expect that this will eventually become the standard way to boot a USB device. However, many motherboards will support BOTH methods, and many older motherboards have USBZIP support.
Some newer BIOSs which support USB 2.0 will not boot from an older pen drive. Using a USB 2.0 compliant one usually solves this problem. Also, some older BIOSs which only support USB 1.1 will not boot from newer drives which support USB 2.0!
TODO
Testing/further research has to be conducted to determine:
- if a bootable-flagged partition / grub doesn't mess openmoko up
- if the phone can still act as a phone, or if the booted os can use the gprs functions
- if the phone can recharge on mass storage mode (from the usb cable)
- if a dedicated partition for each payload is needed (see memtest example...)
- if multi-boot is possible: grub?
Linux distro Howto: liveCD 2 liveUSB
Summary: When the neo/openmoko device is connected in mass storage mode to a linux host,
- Partition the transflash into livecd (bootable flag) & home partition
- Format the created partitions
- Extract the iso's contents onto the livecd partition
- Rename isolinux.cfg and edit it syslinux.cfg (see ubuntu tutorial link)
- Make the partition bootable using syslinux:
$ sudo syslinux -f /dev/sd?
- Howto install ubuntu (or any other distro) on usb stick
- Gentoo on usb stick
- Windows & Linux tutorials & resources:
* Flash installation via Windows: XUbuntu, DSL, Knoppix, Slax, MiniMe * Flash installation via Linux: Ubuntu Edgy, Knoppix, PCLinuxOS
Transflash partitioning schema example
- 2 Gb: /dev/sd? (where N is the transflash's number)
- 700 Mb: /dev/sd?1 : containing bootable iso, FAT16
- 1300 Mb: /dev/sd?2 : openmoko & bootable os home partition, EXT3?
- + eventually a swap
The limitation of this method is that the booted OS is static (not-self modifiable). There's the option to install linux using the partition, but it's not really mobility-oriented (liveCDs are optimized for maximum autoconfiguration).
Alternative methods
The ideal way of doing it would be to have a bootloader on the usb flash, which would offer booting directly from an iso (stored on the very same device). This way, just download the new iso, and it's updated !
Hints to explore:
- Isoemu By using it, we can boot our system from a local iso file, if this iso file is bootable (well, i'd like to see that :p)
- Grub? From How to install grub on an usb pendrive:
If you want to boot from a iso file on a harddisk, do something in menu.lst like title Boot from iso on a harddisk map (hdX,Y)/your.iso (hdZ) map --rehook chainloader (hdZ)+1 rootnoverify (hdZ) boot
Grub & memdisk can boot floppy images, but (AFAIK) not isos. Example from the stock /boot/grub/menu.lst ubuntu:
title Ubuntu, memtest86+ root (hd0,2) kernel /memtest86+.bin quiet boot
Using the memdisk kernel from the syslinux package, you can load disk images and execute them in a non-emulated environment.
bootfrom=/dev/hda1/KNX.iso
Bootfrom needs access to a running Knoppix-System with the same Kernel as the Bootkernel, before it is able to mount the partition / ISO-Image.
- Maybe there's a way to achieve a boot cd iso selecter see (this post)
- virtualization-oriented distro... ex Xenoppix Cons: would work best only on modern VT-capable computers
Using Qemu to boot Linux from a flash drive within Windows
The following tutorial explains how to use Qemu to boot Linux from a portable USB flash device while still working within Windows. This Enables the user to have both systems running at the same time eliminating the need to restart the PC and set your BIOS options to boot Linux.
Interesting distros/payloads
System diagnostics / recovery
- Memtest86+ Very small
- The Ultimate Boot CD
- System Rescue CD
- Recovery IS Possible < 80 MB
General purpose
- Knoppix 700 MB CD-ROM
- PuppyLinux < 100 MB
Security-oriented: pentesting, forensics, anonymous webbrowsing
The SabayonLinux distro offers a lot of boot cheatcodes, such as booting onto GeexBox. We should take a look at the method used.
List of live distros @ livecdlist.com Includes sizes
List of live distros @ wikipedia