G74SX in-circuit reprogram of BIOS SPI

Discussion in 'ASUS Gaming Notebook Forum' started by Sir Robin, Apr 11, 2012.

Thread Status:
Not open for further replies.
  1. Sir Robin

    Sir Robin Notebook Geek

    Reputations:
    8
    Messages:
    84
    Likes Received:
    5
    Trophy Points:
    16
    Awesome, thanks for the details! :)

    BTW, tried sending a PM, but hit a block. You may not have PM rights yet,
    or have it disabled ;)

    Sir Robin
     
  2. Wozzzaaa

    Wozzzaaa Newbie

    Reputations:
    0
    Messages:
    3
    Likes Received:
    0
    Trophy Points:
    5
    Hmmm, no PM. Send me a email.


    Out of curiosity, how did you work out the correct offset for the Asus flash?
     
  3. Sir Robin

    Sir Robin Notebook Geek

    Reputations:
    8
    Messages:
    84
    Likes Received:
    5
    Trophy Points:
    16
    When I first dumped my SPI flash, I was concerned that Easyflash had
    completely trashed it's contents. I could not find any patterns that
    matched the upgrade file. Looking at the upgrade file, it appeared that
    Asus was running in non-descriptor mode. In the dump, I could see my hard drive
    directory tree starting at about 1.5MB, so I knew it was, at least partially,
    corrupted. There were a lot of unknowns, and few hard facts. I ran a few
    experiments, to test the non-descriptor mode theory (loading the upgrade file
    at 0x000000, etc). They show minor improvements, but were clearly not correct.
    After a couple of days, it occurred to me that some section, of the upgrade image,
    must be providing the processor reset vectors. If the upgrade file was a binary
    image, that was not parsed, then the reset vectors should be at the end (the BIOS
    flash is always setup to occupy the end of 32 bit processor space). I took a closer
    look at the end of the upgrade file, and determined that it contained the vector table.
    Then everything fell into place. I went back, and re-examined my SPI dump. I compared
    0x-0x3FF to another machine, based on the H6xx series, and determined that the
    descriptor table was likely in good shape. I also realized that Asus was padding
    the first 512KB of the upgrade file. The actual "real" code starts at 2MB. I then knew
    enough to take a good guess at where the splice should occur. Thankfully, the contents of
    my SPI device were only corrupted in the area that Easyflash "updated" (last 2.5MB) :)

    The formula, for calculating the splice offset, ends up being quite simple:

    Splice_Offset = ((SPI_Device_Size) - (Upgrade_File_Size))

    Anything below the Spice_Offset should come from the SPI device dump.
    The upgrade file should be pasted into the reconstructed image, starting
    at the Splice_Offset.

    Sir Robin
     
  4. ijatboy

    ijatboy Newbie

    Reputations:
    0
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    5
    can you upload the file ? thx in advance
     
  5. BlueNasser

    BlueNasser Notebook Consultant

    Reputations:
    4
    Messages:
    113
    Likes Received:
    0
    Trophy Points:
    30
  6. Sir Robin

    Sir Robin Notebook Geek

    Reputations:
    8
    Messages:
    84
    Likes Received:
    5
    Trophy Points:
    16
    Sorry to hear about your "bricking" BlueNasser :(

    As for replacing the chip, yeah, that should work, if you get
    one with the full image. It is unclear if that vendor is providing
    a complete image (taken from a running unit), or simply programming
    the update file, into the flash. If they are only programming the
    update file, it will not work. I have read several reports, from people,
    who bought pre-programmed SPI chips, from online/ebay vendors,
    that did not work. The vendor you listed is one of biggest on Ebay,
    so it is possible that they have a full image. If you have access to
    a programmer, you can dump the contents of the pre-programmed
    device, and see if it contains a Descriptor Table, similar the one I
    posted in this thread:

    http://forum.notebookreview.com/asus-gaming-notebook-forum/668404-g73jh-bios-chip-replacement-5.html#post8721890

    If so, and the end of the device has code that matches the end
    of the update file, you should be in good shape. If you don't see
    those things, the chip is not likely to work, and I would not
    recommend installing it. Rather, I would suggest removing you old
    chip, and dumping the contents, to a file (using a programmer).
    Then do the reconstruction method, and write the new file to the
    Ebay device, or your original. Be sure to save a copy of the Ebay
    device, just in case. As always, if you are still under warranty,
    the safest course of action is to request an RMA.

    Good Luck,

    Sir Robin
     
  7. BlueNasser

    BlueNasser Notebook Consultant

    Reputations:
    4
    Messages:
    113
    Likes Received:
    0
    Trophy Points:
    30
    Thank you very much Sir Robin.
    I took the laptop to ASUS. They told me they can't replace the BIOS chip but instead they will replace the motherboard :S. I said ok as long as im not paying :D.
    It's still under warranty.
     
  8. BlueNasser

    BlueNasser Notebook Consultant

    Reputations:
    4
    Messages:
    113
    Likes Received:
    0
    Trophy Points:
    30
    Hi again.
    After I got my laptop back, it was fixed and it has 203 BIOS. Unfortunalty the keyboard backlight stopped working. I found a fix for the G73 but im not sure if it will work with g74sx or not.
    your help will be appreciated.
     
  9. Sir Robin

    Sir Robin Notebook Geek

    Reputations:
    8
    Messages:
    84
    Likes Received:
    5
    Trophy Points:
    16
    Glad it's working again BlueNasser!

    I assume you're referring to Gary's Keyboard Blacklight Fix, mentioned in this thread?

    http://forum.notebookreview.com/asus-gaming-notebook-forum/659017-g74sx-keyboard-backlight-disabled.html

    I have not seen any clear reports that it works on the G74SX.
    It has been a while since I researched the issue, so there may
    be updates out there. It may work, but the jury is still out on
    that one, from my perspective. I have not had a chance to dig
    into the issue further, since the last exchange in the thread. I
    will get there, but free time has been short recently. If you have
    access to anyone, who can provide a working image copy, you can
    use the trick I outlined in the above thread. Otherwise, you can
    try making a working image copy of your bios, and then try Gary's
    fix. As long as it does not brick your laptop, you can restore
    your working copy, if the fix does not help.

    Good luck, and report back if you try Gary's fix,

    Sir Robin
     
  10. BlueNasser

    BlueNasser Notebook Consultant

    Reputations:
    4
    Messages:
    113
    Likes Received:
    0
    Trophy Points:
    30
    Thank you man
    Could you please send me a copy of your bios
     
Loading...
Thread Status:
Not open for further replies.

Share This Page