Simon Glass | ba93f4e | 2013-11-10 10:27:05 -0700 | [diff] [blame] | 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); |
Che-Liang Chiou | d297e08 | 2013-11-10 10:27:08 -0700 | [diff] [blame] | 193 | memcpy(&tpm->nvdata[seq], sendbuf + 22, length); |
Simon Glass | ba93f4e | 2013-11-10 10:27:05 -0700 | [diff] [blame] | 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 | } |