Luigi Semenzato | a8cba99 | 2010-09-21 14:12:15 -0700 | [diff] [blame] | 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 \ |
Luigi Semenzato | 35a6cb7 | 2010-11-02 10:37:16 -0700 | [diff] [blame] | 19 | > /dev/null 2>&1; then |
Luigi Semenzato | a8cba99 | 2010-09-21 14:12:15 -0700 | [diff] [blame] | 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 |