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-devi...
.
On the Snow board, this hole ships with no screw in it.
Are you sure about that? There should be a screw there...
I guess I should not have spoken for all Snow boards, but mine certainly did not have a screw in the write-protect screw hole--only the metallic sticker. I did notice this the first time I opened it up, but I wasn't sure what to make of it.
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.
Thanks for responding. I took your advice and disconnected the battery for several minutes. After reassembling the board and running flashrom --wp-disable again I am receiving the same message (FAILED). flashrom --wp-status says:
WP: status: 0x00b8 WP: status.srp0: 1 WP: status.srp1: 0 WP: write protect is enabled. WP: write protect range: start=0x00000000, len=0x00200000
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/S...
I don't have voltmeter; I'm sure I could locate one given enough time though. Do you have any other suggestions as to steps I might be overlooking here? Otherwise, what should I be looking for specifically in the Winbond data sheet?