chromiumos gbb flags on Acer c720

gistfile1.txt

Default flags 0x0 

sudo /usr/share/vboot/bin/set_gbb_flags.sh -d 0x489
flashrom v0.9.4  : 0fd37a2 : Feb 11 2015 23:05:29 UTC on Linux 3.8.11 (x86_64), built with libpci 3.1.10, GCC 4.9.x-google 20140827 (prerelease), little endian
Reading flash... SUCCESS
Setting GBB flags from flags: 0x00000000 to 0x489..successfully saved new image to: /tmp/tmp.T8G57Od06U
flashrom v0.9.4  : 0fd37a2 : Feb 11 2015 23:05:29 UTC on Linux 3.8.11 (x86_64), built with libpci 3.1.10, GCC 4.9.x-google 20140827 (prerelease), little endian
Erasing and writing flash chip... Verifying flash... VERIFIED.          
SUCCESS


Help output
Changes ChromeOS Firmware GBB Flags value.

  Usage: /usr/share/vboot/bin/set_gbb_flags.sh [option_flags] GBB_FLAGS_VALUE
  
  Defined flags (some values may be not supported by all systems):

  GBB_FLAG_DEV_SCREEN_SHORT_DELAY     0x00000001
  GBB_FLAG_LOAD_OPTION_ROMS           0x00000002
  GBB_FLAG_ENABLE_ALTERNATE_OS        0x00000004
  GBB_FLAG_FORCE_DEV_SWITCH_ON        0x00000008
  GBB_FLAG_FORCE_DEV_BOOT_USB         0x00000010
  GBB_FLAG_DISABLE_FW_ROLLBACK_CHECK  0x00000020
  GBB_FLAG_ENTER_TRIGGERS_TONORM      0x00000040
  GBB_FLAG_FORCE_DEV_BOOT_LEGACY      0x00000080
  GBB_FLAG_FAFT_KEY_OVERIDE           0x00000100
  GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC   0x00000200
  GBB_FLAG_DEFAULT_DEV_BOOT_LEGACY    0x00000400
  GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC   0x00000800

  To get a developer-friendly device, try 0x11 (short_delay + boot_usb).
  For factory-related tests (always DEV), try 0x39.

flags:
  -d,--[no]debug:  Provide debug messages (default: false)
  -f,--file:  Path to firmware image. Default to system firmware. (default: '')
  --[no]check_wp:  Check write protection states first. (default: true)
  -h,--[no]help:  show this help (default: false)