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Originally Posted by arivero
the adventure of reverse engineering the librie can be followed in a yahoo mailing list. First surprising thing: no japanese involved!!! It seems japanese hackers were not interested on the posibilities of the machine.
First step become when people dissected the file format of the upgrades. The upgrade is via the USB connection, not need to be online, using a PC application provided by sony. A person -who has not got a librie!!- did a small program able to repackage a linux filesystem and to recalculate checksums. Then some others started the "librie translation project", using this tool to create a japanese librie.
At some time in the project, they decided to introduce a trick to execute scripts: a new entry in the rc.d inits looking for a file named "hook.sh" in the memory stick, and executing it if available.
Now the source code enters play. One of the tarballs genuine from sony was a driver module for communication via the USB. And they did use of it to login. Genuine modification of a module in the source code!
(will follow later)
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It follows.
After getting comunication with the machine, another guy took a look to anothed patch of the kernel source: the module to control the framebuffered e-ink. Using the knowledge *and headers* of this module, he wrote a C program to flash 4 bit images in the framebuffer independently of the sony private, not X11 and not released Display Manager. Also he did another communication module to get the images via USB from a host computer.
Then, I took these ideas and compiled the typical netpbm graphical utilities and some djvu extractors, to show how the previous upload trick could be used to write some stand alone viewers. I engineered the thing in a way that the main demo was done from bash, so no need of compiled to do another demos. I got stuck with the keyboard access, getting only some primitive reading of the keyboard
Also I compiled xvfb so that a x11 aplication can run in the librie in a very retorted way: you run it over the virtual framebuffer and a paralell process every second captures the virtual screen and uses the pnmtools to process it into a 4 bit image that can be injected into the display.
Then after some months of inactivity another bored -and brilliant- engineer took seriously the question of the keyboard, tracked the sony code and got the way to control the keyboard buffer. So very recently the first independent browser for the librie has been released. C code here, no bash tricks! Actually, Jennings his SimpleReader is not so simple, as it can use unicode.
Almost at the same time, someone took the job of getting a ppp bridge to work, old stile, over the already stablished usb terminal entry. So now it is possible also to wget from the sony, but no demo of a browser has been released.
Note that the last two advances are only some weeks old, and consider how much time the device have been in the (japanese) market!