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
|
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2011 The ChromiumOS Authors. All rights reserved.
*
* 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; version 2 of the License.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <types.h>
#include <string.h>
#include <console/console.h>
#include <pc80/mc146818rtc.h>
#include <cpu/x86/car.h>
#include "chromeos.h"
#define VBNV_BLOCK_SIZE 16 /* Size of NV storage block in bytes */
/* Constants for NV storage. We use this rather than structs and
* bitfields so the data format is consistent across platforms and
* compilers.
*/
#define HEADER_OFFSET 0
#define HEADER_MASK 0xC0
#define HEADER_SIGNATURE 0x40
#define HEADER_FIRMWARE_SETTINGS_RESET 0x20
#define HEADER_KERNEL_SETTINGS_RESET 0x10
#define BOOT_OFFSET 1
#define BOOT_DEBUG_RESET_MODE 0x80
#define BOOT_TRY_B_COUNT_MASK 0x0F
#define RECOVERY_OFFSET 2
#define LOCALIZATION_OFFSET 3
#define DEV_FLAGS_OFFSET 4
#define DEV_BOOT_USB_MASK 0x01
#define FIRMWARE_FLAGS_OFFSET 5
#define FIRMWARE_TEST_ERR_FUNC_MASK 0x38
#define FIRMWARE_TEST_ERR_FUNC_SHIFT 3
#define FIRMWARE_TEST_ERR_NUM_MASK 0x07
#define KERNEL_FIELD_OFFSET 11
#define CRC_OFFSET 15
static int vbnv_initialized CAR_GLOBAL;
uint8_t vbnv[CONFIG_VBNV_SIZE] CAR_GLOBAL;
/* Return CRC-8 of the data, using x^8 + x^2 + x + 1 polynomial. A
* table-based algorithm would be faster, but for only 15 bytes isn't
* worth the code size.
*/
static uint8_t crc8(const uint8_t * data, int len)
{
unsigned crc = 0;
int i, j;
for (j = len; j; j--, data++) {
crc ^= (*data << 8);
for (i = 8; i; i--) {
if (crc & 0x8000)
crc ^= (0x1070 << 3);
crc <<= 1;
}
}
return (uint8_t) (crc >> 8);
}
static void vbnv_setup(void)
{
int i;
for (i = 0; i < CONFIG_VBNV_SIZE; i++)
vbnv[i] = cmos_read(CONFIG_VBNV_OFFSET + 14 + i);
/* Check data for consistency */
if ((HEADER_SIGNATURE != (vbnv[HEADER_OFFSET] & HEADER_MASK))
|| (crc8(vbnv, CRC_OFFSET) != vbnv[CRC_OFFSET])) {
/* Data is inconsistent (bad CRC or header),
* so reset to defaults
*/
memset(vbnv, 0, VBNV_BLOCK_SIZE);
vbnv[HEADER_OFFSET] =
(HEADER_SIGNATURE | HEADER_FIRMWARE_SETTINGS_RESET |
HEADER_KERNEL_SETTINGS_RESET);
}
vbnv_initialized = 1;
}
int get_recovery_mode_from_vbnv(void)
{
if (!vbnv_initialized)
vbnv_setup();
return vbnv[RECOVERY_OFFSET];
}
|
