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1 | /* |
2 | * Copyright (c) 2013 Google, Inc | |
3 | * | |
4 | * SPDX-License-Identifier: GPL-2.0+ | |
5 | */ | |
6 | ||
7 | #include <common.h> | |
8 | #include <asm/state.h> | |
9 | #include <asm/unaligned.h> | |
10 | #include <linux/crc8.h> | |
11 | ||
12 | /* TPM NVRAM location indices. */ | |
13 | #define FIRMWARE_NV_INDEX 0x1007 | |
14 | #define KERNEL_NV_INDEX 0x1008 | |
15 | ||
16 | #define NV_DATA_PUBLIC_PERMISSIONS_OFFSET 60 | |
17 | ||
18 | /* Kernel TPM space - KERNEL_NV_INDEX, locked with physical presence */ | |
19 | #define ROLLBACK_SPACE_KERNEL_VERSION 2 | |
20 | #define ROLLBACK_SPACE_KERNEL_UID 0x4752574C /* 'GRWL' */ | |
21 | ||
22 | struct rollback_space_kernel { | |
23 | /* Struct version, for backwards compatibility */ | |
24 | uint8_t struct_version; | |
25 | /* Unique ID to detect space redefinition */ | |
26 | uint32_t uid; | |
27 | /* Kernel versions */ | |
28 | uint32_t kernel_versions; | |
29 | /* Reserved for future expansion */ | |
30 | uint8_t reserved[3]; | |
31 | /* Checksum (v2 and later only) */ | |
32 | uint8_t crc8; | |
33 | } __packed rollback_space_kernel; | |
34 | ||
35 | /* | |
36 | * These numbers derive from adding the sizes of command fields as shown in | |
37 | * the TPM commands manual. | |
38 | */ | |
39 | #define TPM_REQUEST_HEADER_LENGTH 10 | |
40 | #define TPM_RESPONSE_HEADER_LENGTH 10 | |
41 | ||
42 | /* These are the different non-volatile spaces that we emulate */ | |
43 | enum { | |
44 | NV_GLOBAL_LOCK, | |
45 | NV_SEQ_FIRMWARE, | |
46 | NV_SEQ_KERNEL, | |
47 | NV_SEQ_COUNT, | |
48 | }; | |
49 | ||
50 | /* Size of each non-volatile space */ | |
51 | #define NV_DATA_SIZE 0x20 | |
52 | ||
53 | /* | |
54 | * Information about our TPM emulation. This is preserved in the sandbox | |
55 | * state file if enabled. | |
56 | */ | |
57 | static struct tpm_state { | |
58 | uint8_t nvdata[NV_SEQ_COUNT][NV_DATA_SIZE]; | |
59 | } state; | |
60 | ||
61 | /** | |
62 | * sandbox_tpm_read_state() - read the sandbox EC state from the state file | |
63 | * | |
64 | * If data is available, then blob and node will provide access to it. If | |
65 | * not this function sets up an empty TPM. | |
66 | * | |
67 | * @blob: Pointer to device tree blob, or NULL if no data to read | |
68 | * @node: Node offset to read from | |
69 | */ | |
70 | static int sandbox_tpm_read_state(const void *blob, int node) | |
71 | { | |
72 | const char *prop; | |
73 | int len; | |
74 | int i; | |
75 | ||
76 | if (!blob) | |
77 | return 0; | |
78 | ||
79 | for (i = 0; i < NV_SEQ_COUNT; i++) { | |
80 | char prop_name[20]; | |
81 | ||
82 | sprintf(prop_name, "nvdata%d", i); | |
83 | prop = fdt_getprop(blob, node, prop_name, &len); | |
84 | if (prop && len == NV_DATA_SIZE) | |
85 | memcpy(state.nvdata[i], prop, NV_DATA_SIZE); | |
86 | } | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
91 | /** | |
92 | * cros_ec_write_state() - Write out our state to the state file | |
93 | * | |
94 | * The caller will ensure that there is a node ready for the state. The node | |
95 | * may already contain the old state, in which case it is overridden. | |
96 | * | |
97 | * @blob: Device tree blob holding state | |
98 | * @node: Node to write our state into | |
99 | */ | |
100 | static int sandbox_tpm_write_state(void *blob, int node) | |
101 | { | |
102 | int i; | |
103 | ||
104 | /* | |
105 | * We are guaranteed enough space to write basic properties. | |
106 | * We could use fdt_add_subnode() to put each set of data in its | |
107 | * own node - perhaps useful if we add access informaiton to each. | |
108 | */ | |
109 | for (i = 0; i < NV_SEQ_COUNT; i++) { | |
110 | char prop_name[20]; | |
111 | ||
112 | sprintf(prop_name, "nvdata%d", i); | |
113 | fdt_setprop(blob, node, prop_name, state.nvdata[i], | |
114 | NV_DATA_SIZE); | |
115 | } | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
120 | SANDBOX_STATE_IO(sandbox_tpm, "google,sandbox-tpm", sandbox_tpm_read_state, | |
121 | sandbox_tpm_write_state); | |
122 | ||
123 | static int index_to_seq(uint32_t index) | |
124 | { | |
125 | switch (index) { | |
126 | case FIRMWARE_NV_INDEX: | |
127 | return NV_SEQ_FIRMWARE; | |
128 | case KERNEL_NV_INDEX: | |
129 | return NV_SEQ_KERNEL; | |
130 | case 0: | |
131 | return NV_GLOBAL_LOCK; | |
132 | } | |
133 | ||
134 | printf("Invalid nv index %#x\n", index); | |
135 | return -1; | |
136 | } | |
137 | ||
138 | int tis_sendrecv(const u8 *sendbuf, size_t send_size, | |
139 | u8 *recvbuf, size_t *recv_len) | |
140 | { | |
141 | struct tpm_state *tpm = &state; | |
142 | uint32_t code, index, length, type; | |
143 | uint8_t *data; | |
144 | int seq; | |
145 | ||
146 | code = get_unaligned_be32(sendbuf + sizeof(uint16_t) + | |
147 | sizeof(uint32_t)); | |
148 | printf("tpm: %zd bytes, recv_len %zd, cmd = %x\n", send_size, | |
149 | *recv_len, code); | |
150 | print_buffer(0, sendbuf, 1, send_size, 0); | |
151 | switch (code) { | |
152 | case 0x65: /* get flags */ | |
153 | type = get_unaligned_be32(sendbuf + 14); | |
154 | switch (type) { | |
155 | case 4: | |
156 | index = get_unaligned_be32(sendbuf + 18); | |
157 | printf("Get flags index %#02x\n", index); | |
158 | *recv_len = 22; | |
159 | memset(recvbuf, '\0', *recv_len); | |
160 | put_unaligned_be32(22, recvbuf + | |
161 | TPM_RESPONSE_HEADER_LENGTH); | |
162 | data = recvbuf + TPM_RESPONSE_HEADER_LENGTH + | |
163 | sizeof(uint32_t); | |
164 | switch (index) { | |
165 | case FIRMWARE_NV_INDEX: | |
166 | break; | |
167 | case KERNEL_NV_INDEX: | |
168 | /* TPM_NV_PER_PPWRITE */ | |
169 | put_unaligned_be32(1, data + | |
170 | NV_DATA_PUBLIC_PERMISSIONS_OFFSET); | |
171 | break; | |
172 | } | |
173 | break; | |
174 | case 0x11: /* TPM_CAP_NV_INDEX */ | |
175 | index = get_unaligned_be32(sendbuf + 18); | |
176 | printf("Get cap nv index %#02x\n", index); | |
177 | put_unaligned_be32(22, recvbuf + | |
178 | TPM_RESPONSE_HEADER_LENGTH); | |
179 | break; | |
180 | default: | |
181 | printf(" ** Unknown 0x65 command type %#02x\n", | |
182 | type); | |
183 | return -1; | |
184 | } | |
185 | break; | |
186 | case 0xcd: /* nvwrite */ | |
187 | index = get_unaligned_be32(sendbuf + 10); | |
188 | length = get_unaligned_be32(sendbuf + 18); | |
189 | seq = index_to_seq(index); | |
190 | if (seq < 0) | |
191 | return -1; | |
192 | printf("tpm: nvwrite index=%#02x, len=%#02x\n", index, length); | |
2c30af8f | 193 | memcpy(&tpm->nvdata[seq], sendbuf + 22, length); |
ed3f5a30 SG |
194 | *recv_len = 12; |
195 | memset(recvbuf, '\0', *recv_len); | |
196 | break; | |
197 | case 0xcf: /* nvread */ | |
198 | index = get_unaligned_be32(sendbuf + 10); | |
199 | length = get_unaligned_be32(sendbuf + 18); | |
200 | seq = index_to_seq(index); | |
201 | if (seq < 0) | |
202 | return -1; | |
203 | printf("tpm: nvread index=%#02x, len=%#02x\n", index, length); | |
204 | *recv_len = TPM_RESPONSE_HEADER_LENGTH + sizeof(uint32_t) + | |
205 | length; | |
206 | memset(recvbuf, '\0', *recv_len); | |
207 | put_unaligned_be32(length, recvbuf + | |
208 | TPM_RESPONSE_HEADER_LENGTH); | |
209 | if (seq == NV_SEQ_KERNEL) { | |
210 | struct rollback_space_kernel rsk; | |
211 | ||
212 | data = recvbuf + TPM_RESPONSE_HEADER_LENGTH + | |
213 | sizeof(uint32_t); | |
214 | rsk.struct_version = 2; | |
215 | rsk.uid = ROLLBACK_SPACE_KERNEL_UID; | |
216 | rsk.kernel_versions = 0; | |
217 | rsk.crc8 = crc8((unsigned char *)&rsk, | |
218 | offsetof(struct rollback_space_kernel, | |
219 | crc8)); | |
220 | memcpy(data, &rsk, sizeof(rsk)); | |
221 | } else { | |
222 | memcpy(recvbuf + TPM_RESPONSE_HEADER_LENGTH + | |
223 | sizeof(uint32_t), &tpm->nvdata[seq], length); | |
224 | } | |
225 | break; | |
226 | case 0x14: /* tpm extend */ | |
227 | case 0x15: /* pcr read */ | |
228 | case 0x5d: /* force clear */ | |
229 | case 0x6f: /* physical enable */ | |
230 | case 0x72: /* physical set deactivated */ | |
231 | case 0x99: /* startup */ | |
232 | case 0x4000000a: /* assert physical presence */ | |
233 | *recv_len = 12; | |
234 | memset(recvbuf, '\0', *recv_len); | |
235 | break; | |
236 | default: | |
237 | printf("Unknown tpm command %02x\n", code); | |
238 | return -1; | |
239 | } | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | int tis_open(void) | |
245 | { | |
246 | printf("%s\n", __func__); | |
247 | return 0; | |
248 | } | |
249 | ||
250 | int tis_close(void) | |
251 | { | |
252 | printf("%s\n", __func__); | |
253 | return 0; | |
254 | } | |
255 | ||
256 | int tis_init(void) | |
257 | { | |
258 | printf("%s\n", __func__); | |
259 | return 0; | |
260 | } |