On Mon, Dec 16, 2013 at 9:14 AM, <BM-2cWKH3wgq8zXX9eHfba16oTc8b61ead4Yq@bitmessage.ch> wrote:
Hello flashrom developers,

I'm having trouble disabling write-protection on my Samsung Arm
Chromebook. So far I've removed the metallic sticker covering the
"write-protect screw hole" according to the pictures on the Chromium wiki
<http://www.chromium.org/chromium-os/developer-information-for-chrome-os-devices/samsung-arm-chromebook>.
On the Snow board, this hole ships with no screw in it.

Are you sure about that? There should be a screw there...
 
As root in
developer mode, the output of flashrom -v is "flashrom v0.9.4  : 4169bc8
...". The first time I ran flashrom --wp-disable, I got a message saying
the operation FAILED with error=1. At that point I took the board apart
again and cleaned the write-protect screw hole with q-tips dipped in
rubbing alcohol. When I reassembled the Chromebook and tried again with
flashrom -V --wp-disable, the last few lines I receive are:

w25_set_srp0: old status: 0xb8
w25_set_srp0: new status: 0xb8
w25q_disable_writeprotect(): error=1.
No -i argument is specified, set ignore_fmap.
FAILED
restore_power_management(): Power management enabled

As you can see, I can't seem to disable write protection on this chip. I'm
running stock ChromeOS. Any idea what I might be doing wrong? Thanks in
advance.

That's weird... Since you have the system taken apart already, can you try disconnecting the battery while the machine is unplugged? I'd recommend leaving it disconnected for a minute or so, the idea being to give the SPI ROM enough time to fully discharge and reset.

If you have a voltmeter handy, you can also try measuring the voltage on the /WP pin (pin 3). More details on pin configuration can be found in the datasheet: http://www.winbond-usa.com/hq/enu/ProductAndSales/ProductLines/FlashMemory/SerialFlash/W25Q32DW.htm

--
David Hendricks (dhendrix)
Systems Software Engineer, Google Inc.