WebOS Exploration - Various Information
From WebOS Internals
webOS is a open source based operating system, running a Linux kernel based off of 2.6.24. This page serves as a collection of information and subtopics, with the end goal of accessing linux, which has, as you can see, been accomplished.
Public Restore Image Found!
This contains the entire webOS image, as well as a flash tool and other goodies: http://palm.cdnetworks.net/rom/pre_p100eww/webosdoctorp100ewwsprint.jar
Novacom Restore Program
The Java program installs something called NovaComd, which seems to be a driver for the Pre that provides various tools.
It uses rules for each kind of device, the Pre being "castle", in the device's flashing process. The program also has access to the mentioned NovaComd driver, and judging from the program bytecode, allows lots of useful things such as executing programs in the Linux OS of the Pre.
Known Novacom commands:
This will retrieve the log file off your Pre:
novacom get file://klog > log.txt
If the webOS device is in debug mode, this will open a command line to the device (will work against the emulator as well):
novacom -t open tty://
This creates a file on the device:
novacom put file://tmp/newfile < localfile
Note: Under a Windows command line, you will need to enter a end-of-file character (^Z) to close the stream.
Running webOS in QEMU
Running webOS in Sun xVM
Untested, but apparently there's a virtual machine called Virtura from the InvisibleMan videos from the forums on precentral, that can run webOS as an application. This gives you the emulator functionality.
Try it and see if you can get it working with the boot image from webOS Doctor.