1 #! /bin/sh -e 2 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved. 3 # Use of this source code is governed by a BSD-style license that can be 4 # found in the LICENSE file. 5 # 6 # Finds the largest NV space that can be defined on the TPM in this state 7 # (i.e. without removing existing spaces). 8 # 9 # The TPM must be unowned, and physical presence must be on. 10 11 low=1 12 high=1500 13 try=$high 14 15 # Binary search with no upper bound 16 while true; do 17 ## echo trying $try [ $low $high ] 18 if /usr/bin/tpmc definespace 0xf004 $(printf "0x%x" $try) 0x1 \ 19 > /dev/null 2>&1; then 20 # definespace success: end, or $try must grow 21 if [ $try -eq $low ]; then 22 echo $low 23 exit 0 24 elif [ $try -lt $high ]; then 25 low=$try 26 try=$(( ( $high + $low ) / 2 )) 27 else 28 # special case: when try == high, expand the search 29 low=$try 30 try=$(( $try * 2 )) 31 high=$try 32 fi 33 else 34 # check for unexpected errors 35 result=$? 36 if [ $result -ne 17 ]; then 37 echo running tpmc definespace 0xf004 0x1 0x1 38 /usr/bin/tpmc definespace 0xf004 0x1 0x1 39 echo please correct this condition and try again 40 exit 1 41 fi 42 # definespace failure: end, or $try must shrink 43 if [ $try -eq $low ]; then 44 echo 0 45 exit 0 46 fi 47 high=$try 48 try=$(( ( $high + $low ) / 2 )) 49 fi 50 done 51
