1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
/*
* Copyright (C) 2017 Intel Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but without any warranty; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <arch/early_variables.h>
#include <stdint.h>
#include <compiler.h>
#include <string.h>
#include <assert.h>
#include <commonlib/endian.h>
#include <console/console.h>
#include <delay.h>
#include <device/i2c_simple.h>
#include <endian.h>
#include <lib.h>
#include <security/tpm/tis.h>
#include <timer.h>
#define RECV_TIMEOUT (1 * 1000) /* 1 second */
#define XMIT_TIMEOUT (1 * 1000) /* 1 second */
#define SLEEP_DURATION 1000 /* microseconds */
struct tpm_output_header {
uint16_t tag;
uint32_t length;
uint32_t return_code;
} __packed;
int tis_open(void)
{
return 0;
}
int tis_close(void)
{
return 0;
}
int tis_init(void)
{
return 0;
}
int tis_sendrecv(const uint8_t *sendbuf, size_t sbuf_size,
uint8_t *recvbuf, size_t *rbuf_len)
{
size_t hdr_bytes;
struct tpm_output_header *header;
size_t max_recv_bytes;
size_t recv_bytes;
int status;
struct stopwatch sw;
ASSERT(sbuf_size >= 10);
if (IS_ENABLED(CONFIG_DRIVER_TPM_DISPLAY_TIS_BYTES)) {
/* Display the TPM command */
if (sbuf_size >= 10)
printk(BIOS_DEBUG, "TPM Command: 0x%08x\n",
read_at_be32(sendbuf, sizeof(uint16_t)
+ sizeof(uint32_t)));
hexdump(sendbuf, sbuf_size);
}
/* Send the command to the TPM */
stopwatch_init_msecs_expire(&sw, XMIT_TIMEOUT);
while (1) {
status = i2c_write_raw(CONFIG_DRIVER_TPM_I2C_BUS,
CONFIG_DRIVER_TPM_I2C_ADDR, (uint8_t *)sendbuf,
sbuf_size);
if ((status < 0) && (!stopwatch_expired(&sw)))
continue;
if (status < 0)
return status;
break;
}
/* Read the TPM response header */
max_recv_bytes = *rbuf_len;
ASSERT(max_recv_bytes >= sizeof(*header));
hdr_bytes = sizeof(*header);
header = (struct tpm_output_header *)recvbuf;
stopwatch_init_msecs_expire(&sw, RECV_TIMEOUT);
do {
status = i2c_read_raw(CONFIG_DRIVER_TPM_I2C_BUS,
CONFIG_DRIVER_TPM_I2C_ADDR, recvbuf, hdr_bytes);
if (status > 0)
break;
udelay(SLEEP_DURATION);
} while (!stopwatch_expired(&sw));
if (status != sizeof(*header))
return -1;
/* Determine the number of bytes remaining */
recv_bytes = min(be32_to_cpu(*(uint32_t *)&header->length),
max_recv_bytes);
/* Determine if there is additional response data */
if (recv_bytes > hdr_bytes) {
/* Display the TPM response */
if (IS_ENABLED(CONFIG_DRIVER_TPM_DISPLAY_TIS_BYTES))
hexdump(recvbuf, hdr_bytes);
/* Read the full TPM response */
status = i2c_read_raw(CONFIG_DRIVER_TPM_I2C_BUS,
CONFIG_DRIVER_TPM_I2C_ADDR, recvbuf, recv_bytes);
if (status < 0)
return status;
}
/* Return the number of bytes received */
*rbuf_len = status;
/* Display the TPM response */
if (IS_ENABLED(CONFIG_DRIVER_TPM_DISPLAY_TIS_BYTES)) {
printk(BIOS_DEBUG, "TPM Response: 0x%08x\n",
read_at_be32(recvbuf, sizeof(uint16_t)
+ sizeof(uint32_t)));
hexdump(recvbuf, *rbuf_len);
}
/* Successful transfer */
return 0;
}
|
