Loading Linux without spinning media
 

What are the most common or easiest or conventional (or whatever) ways to load a Linux kernel and enough application code to do useful things at boot time? Load from flash or other non-volatile memory? Load from spinning media? Network bootloaders? Other?
I would like to run a small list of dedicated applications on either a conventional X86 desktop platform (headless) or a PC/104 system, and I want to avoid spinning media, to improve reliability (at least in theory). What are others doing in this regard?
What is necessary to prepare the object code for use in such a system? How does one install the code into flash, or whatever media? How does one store the object code on a boot host, if network booting is used?
What other things do I need to start thinking about?

--- rod.

A good start would be to check out this site:
http://pendrivelinux.com/

Generally you would be talking about software installed to onboard flash, either Compact Flash through an IDE-adapter (in the case of using standard X86 hardware) or some onboard flash. You could use PXE, but that severely limits your flexibility and mobility, as you are then rather literally tethered to a master server of some type.

As for getting Linux ready for booting from flash/PXE/whatever, there is nothing you really need to do beyond slimming the installation down. By virtue of the way the Linux kernel works, there is no functional difference between installing it to a HDD or a Compact Flash card.

Though you will probably want to compress your filesystem, and run it from RAM, rather than running it directly from flash. This prevents excessive read/write from the media, and speeds things up considerably. It does mean you will need to have a decent amount of RAM in the device as well.

You might want to read something like this to get an idea of how you can get started with a simple installation.

There is a U-boot bootloader presnet which is the customized boot loader for most of the embedded linux application it works fron flash memory try that