log : https://pantheon.corp.google.com/storage/browser/chromiumos-test-logs/bugfiles/cr/685421/?pli=1

<triage> snanda@, could you take a look and assign?

Are we sure that the device was in dev mode when it was booted up?  It appears that the dev mode switch was enabled at boot and was later on disabled.

bios_info.txt:
...
devsw_boot             = 1                              # Developer switch position at boot
devsw_cur              = 0                              # Developer switch current position
...

ZGB only works in normal mode because it fails to boot up in DEV as the 
 Issue 479964  : [Alex/ZGB freon] boot process failed in dev mode. 

Please re-run the test one more time.

Once the system has booted up please run "crossystem" command and attach its output here.  In the original logs it appears that the dev switch position at boot vs current is different.  Lets rule that out as the cause first.

The following is the output of crossystem under about:system:

crossystem --all
arch                   = x86                            # Platform architecture
backup_nvram_request   = 1                              # Backup the nvram somewhere at the next boot. Cleared on success.
battery_cutoff_request = 0                              # Cut off battery and shutdown on next boot.
block_devmode          = 0                              # Block all use of developer mode
clear_tpm_owner_request = 1                              # Clear TPM owner on next boot
clear_tpm_owner_done   = 0                              # Clear TPM owner done
cros_debug             = 0                              # OS should allow debug features
dbg_reset              = 0                              # Debug reset mode request (writable)
debug_build            = 0                              # OS image built for debug features
dev_boot_usb           = 1                              # Enable developer mode boot from USB/SD (writable)
dev_boot_legacy        = 0                              # Enable developer mode boot Legacy OSes (writable)
dev_boot_signed_only   = 0                              # Enable developer mode boot only from official kernels (writable)
dev_default_boot       = disk                           # default boot from legacy or usb (writable)
devsw_boot             = 0                              # Developer switch position at boot
devsw_cur              = 0                              # Developer switch current position
disable_dev_request    = 0                              # Disable virtual dev-mode on next boot
ecfw_act               = RW                             # Active EC firmware
fmap_base              = 0xfff40000                     # Main firmware flashmap physical address
fwb_tries              = 0                              # Try firmware B count (writable)
fw_vboot2              = 0                              # 1 if firmware was selected by vboot2 or 0 otherwise
fwid                   = ZGB.03.61.0740.0062G7.010      # Active firmware ID
fwupdate_tries         = 0                              # Times to try OS firmware update (writable, inside kern_nv)
fw_tried               = A                              # Firmware tried this boot (vboot2)
fw_try_count           = 0                              # Number of times to try fw_try_next (writable)
fw_try_next            = A                              # Firmware to try next (vboot2,writable)
fw_result              = unknown                        # Firmware result this boot (vboot2,writable)
fw_prev_tried          = A                              # Firmware tried on previous boot (vboot2)
fw_prev_result         = unknown                        # Firmware result of previous boot (vboot2)
hwid                   = ACER ZGB BETA-US 2170          # Hardware ID
inside_vm              = 0                              # Running in a VM?
kern_nv                = 0x00000000                     # Non-volatile field for kernel use
kernkey_vfy            = sig                            # Type of verification done on kernel key block
loc_idx                = 0                              # Localization index for firmware screens (writable)
mainfw_act             = A                              # Active main firmware
mainfw_type            = normal                         # Active main firmware type
nvram_cleared          = 0                              # Have NV settings been lost?  Write 0 to clear
oprom_needed           = 0                              # Should we load the VGA Option ROM at boot?
recovery_reason        = 0                              # Recovery mode reason for current boot
recovery_request       = 0                              # Recovery mode request (writable)
recovery_subcode       = 0                              # Recovery reason subcode (writable)
recoverysw_boot        = 0                              # Recovery switch position at boot
recoverysw_cur         = 0                              # Recovery switch current position
recoverysw_ec_boot     = 0                              # Recovery switch position at EC boot
ro_fwid                = ZGB.03.61.0740.0062G7.010      # Read-only firmware ID
sw_wpsw_boot           = (error)                        # Firmware write protect software setting enabled at boot (Baytrail only)
tpm_attack             = 0                              # TPM was interrupted since this flag was cleared
tpm_fwver              = 0x00010002                     # Firmware version stored in TPM
tpm_kernver            = 0x00020002                     # Kernel version stored in TPM
tpm_rebooted           = 0                              # TPM requesting repeated reboot (vboot2)
try_ro_sync            = 0                              # try read only software sync
tried_fwb              = 0                              # Tried firmware B before A this boot
vdat_flags             = 0x00000002                     # Flags from VbSharedData
vdat_lfdebug           = Check A result=12
Check B result=0
Firmware index booted=0x00
TPM combined version at start=0x00010002
Lowest combined version from firmware=0x00010002
 # LoadFirmware() debug data (not in print-all) 

Just found out the device has been recovered to M54 so the output above is in M54. 

In M54, shell is not working in normal mode (as expected). 

I will install the device to M57 and share the crossystem output.   

It's no longer reproducible in 9202.27.0/57.0.2987.52. Close.