1 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6 /* This program mimicks the TPM usage from read-only firmware. It exercises
7 * the TPM functionality needed in the read-only firmware. It is meant to be
8 * integrated with the rest of the read-only firmware. It is also provided as
9 * a test.
10 */
11
12 #include <stdio.h>
13 #include <stdint.h>
14 #include <stdlib.h>
15
16 #include "tlcl.h"
17 #include "utility.h"
18
19 /* These index values are used to create NVRAM spaces. They only need to be
20 * unique.
21 */
22 #define INDEX0 0xda70
23 #define INDEX1 0xda71
24 #define INDEX2 0xda72
25 #define INDEX3 0xda73
26
27 #define INDEX_INITIALIZED 0xda80
28
29 /* This is called once at initialization time. It may be called again from
30 * recovery mode to rebuild the spaces if something incomprehensible happened
31 * and the spaces are gone or messed up. This is called after TPM_Startup and
32 * before the spaces are write-locked, so there is a chance that they can be
33 * recreated (but who knows---if anything can happen, there are plenty of ways
34 * of making this FUBAR).
35 */
InitializeSpaces(void)36 void InitializeSpaces(void) {
37 uint32_t zero = 0;
38 uint32_t perm = TPM_NV_PER_WRITE_STCLEAR | TPM_NV_PER_PPWRITE;
39
40 printf("Initializing spaces\n");
41 TlclSetNvLocked(); /* useful only the first time */
42
43 TlclDefineSpace(INDEX0, perm, 4);
44 TlclWrite(INDEX0, (uint8_t *) &zero, 4);
45 TlclDefineSpace(INDEX1, perm, 4);
46 TlclWrite(INDEX1, (uint8_t *) &zero, 4);
47 TlclDefineSpace(INDEX2, perm, 4);
48 TlclWrite(INDEX2, (uint8_t *) &zero, 4);
49 TlclDefineSpace(INDEX3, perm, 4);
50 TlclWrite(INDEX3, (uint8_t *) &zero, 4);
51
52 perm = TPM_NV_PER_READ_STCLEAR | TPM_NV_PER_WRITE_STCLEAR |
53 TPM_NV_PER_PPWRITE;
54 TlclDefineSpace(INDEX_INITIALIZED, perm, 1);
55 }
56
57
EnterRecoveryMode(void)58 void EnterRecoveryMode(void) {
59 printf("entering recovery mode");
60 exit(0);
61 }
62
63
main(int argc,char ** argv)64 int main(int argc, char** argv) {
65 uint8_t c;
66 uint32_t index_0, index_1, index_2, index_3;
67
68 TlclLibInit();
69
70 TlclStartup();
71 TlclSelfTestFull();
72
73 TlclAssertPhysicalPresence();
74
75 /* Checks if initialization has completed by trying to read-lock a space
76 * that's created at the end of initialization.
77 */
78 if (TlclRead(INDEX_INITIALIZED, &c, 0) == TPM_E_BADINDEX) {
79 /* The initialization did not complete.
80 */
81 InitializeSpaces();
82 }
83
84 /* Checks if spaces are OK or messed up.
85 */
86 if (TlclRead(INDEX0, (uint8_t*) &index_0, sizeof(index_0)) != TPM_SUCCESS ||
87 TlclRead(INDEX1, (uint8_t*) &index_1, sizeof(index_1)) != TPM_SUCCESS ||
88 TlclRead(INDEX2, (uint8_t*) &index_2, sizeof(index_2)) != TPM_SUCCESS ||
89 TlclRead(INDEX3, (uint8_t*) &index_3, sizeof(index_3)) != TPM_SUCCESS) {
90 EnterRecoveryMode();
91 }
92
93 /* Writes space, and locks it. Then attempts to write again. I really wish
94 * I could use the imperative.
95 */
96 index_0 += 1;
97 if (TlclWrite(INDEX0, (uint8_t*) &index_0, sizeof(index_0) != TPM_SUCCESS)) {
98 error("could not write index 0\n");
99 }
100 TlclWriteLock(INDEX0);
101 if (TlclWrite(INDEX0, (uint8_t*) &index_0, sizeof(index_0)) == TPM_SUCCESS) {
102 error("index 0 is not locked\n");
103 }
104
105 /* Done for now.
106 */
107 printf("TEST SUCCEEDED\n");
108 exit(0);
109 }
110