[Xaphiosis]

Porkupan: thank you! I couldn't figure out what I was missing, I read the relevant section of the service manual about 10 times now and still didn't get it.
I was indeed getting the default sony test screen.

Final procedure which worked, then, so anyone else who is confused like I was can benefit:

1. Install boroda firmware, I used 1.05d
2. Take an SD card, on it create the file (can be empty): /Sony Reader/software/autorun.xml
3. Plug in the reader (USB)
4. From the boroda firmware e.g. "PRS600.upd.1.05d.zip" take the "test-autorun" subdirectory and copy it to the reader's internal memory (the disk/partition labeled READER)
5. Rename "test-autorun" on READER to "test"
6. Copy your new firmware into "test" (e.g. new_opt.600.img and new_opt.600.md5 from the boroda firmware "test-flash" directory)
7. Unmount/safely remove READER, then unplug the reader (USB)
8. Turn off the reader (proper shutdown), don't plug it in until after 14.
9. Turn on the reader, wait until home screen finishes loading
10. Press vol+ and home buttons simultaneously, keep pressing while you insert the SD card
11. You should see "Run script" "PRS-700 flasher 0.2a by igorsk/porkupan" and two options
12. "Option: flash the image" -> this doesn't seem to work, the script is referring to new_opt.700.img, I would assume it currently isn't safe to use it
13. "(+): load test firmware" -> this is the option you want. The (+) refers to the zoom button (looking glass with + in it).
    
    When you press zoom, the following should happen:
    "Running script.
    Please wait."
    "Script finished."
    after a bit of time, the script reboots the reader (be patient)
    
14. Your new firmware is running: congrats!
15. Your new firmware in not running: check script.log on READER for ideas as to what could've gone wrong

Additional info: to test that new firmware is indeed loaded, the best idea I have is to modify the existing boroda firmware.
To do a very simple modification, follow these steps
(under linux, I have no idea what do do under windows so I won't speculate):

1. make sure you have the cramfs tools installed (e.g. use this on debian/ubuntu):
   

   sudo apt-get install cramfsprogs

2. take new_opt.600.img and stick it in a new directory
3. unpack the image
   

   sudo cramfsck -x cramfs_600 new_opt.600.img

   Note: use sudo, or you will get

   cramfsck: mknod failed: opt/dev/console: Operation not permitted

4. edit cramfs_600/opt/sony/ebook/application/resources/scripts/main.xml
5. find the line that says
   

   text += "\nRussified: porkupan (boroda)   Version: 1.05d\n\n"

6. change it to
   

   text += "\nRussified: porkupan (boroda) (my hero) Version: 1.05d\n\n"

7. go back to where you unpacked new_opt.600.img
8. pack up the image:
   

   mkcramfs cramfs_600 new_opt.600.img

9. calculate the md5 sum:
   

   md5sum new_opt.600.img > new_opt.600.md5

10. be anal-retentive just in case, make sure it looks like the boroda one:
    

    20025cccb6a0c246298fa2bce453a8ce *new_opt.600.img

    and not like
    

    518fdbd460e4362c7159714755c93012  new_opt.600.img

    (note: one space, then an asterisk (*))
    
11. copy new_opt.600.* into test/ on READER
12. perform the flashing like in previous instructions
13. on your reader, go to: home->more->settings->About
    look at the second paragraph starting with "Russified" and check whether
    porkupan is your hero... if you're running the new firmware, then he is :)

Once again, my thanks to porkupan. I hope I'll manage to hack up something interesting in the future... after my first day of exposure, the xml/js mix looks a bit confusing so far.

I hope someone finds this useful.

Originally Posted by porkupan

1) Created "test" in the internal memory.