Add support for the TPM2_GetCapability command.
Change the command file and the help accordingly.
Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Reviewed-by: Simon Glass sjg@chromium.org --- cmd/tpm-v2.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ include/tpm-v2.h | 14 ++++++++++++++ lib/tpm-v2.c | 33 +++++++++++++++++++++++++++++++++ 3 files changed, 92 insertions(+)
diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c index 49c22aaeaa..3599763e90 100644 --- a/cmd/tpm-v2.c +++ b/cmd/tpm-v2.c @@ -144,6 +144,43 @@ static int do_tpm_pcr_read(cmd_tbl_t *cmdtp, int flag, int argc, return report_return_code(rc); }
+static int do_tpm_get_capability(cmd_tbl_t *cmdtp, int flag, int argc, + char * const argv[]) +{ + u32 capability, property, rc; + u8 *data; + size_t count; + int i, j; + + if (argc != 5) + return CMD_RET_USAGE; + + capability = simple_strtoul(argv[1], NULL, 0); + property = simple_strtoul(argv[2], NULL, 0); + data = map_sysmem(simple_strtoul(argv[3], NULL, 0), 0); + count = simple_strtoul(argv[4], NULL, 0); + + rc = tpm2_get_capability(capability, property, data, count); + if (rc) + goto unmap_data; + + printf("Capabilities read from TPM:\n"); + for (i = 0; i < count; i++) { + printf("Property 0x"); + for (j = 0; j < 4; j++) + printf("%02x", data[(i * 8) + j]); + printf(": 0x"); + for (j = 4; j < 8; j++) + printf("%02x", data[(i * 8) + j]); + printf("\n"); + } + +unmap_data: + unmap_sysmem(data); + + return report_return_code(rc); +} + static cmd_tbl_t tpm2_commands[] = { U_BOOT_CMD_MKENT(info, 0, 1, do_tpm_info, "", ""), U_BOOT_CMD_MKENT(init, 0, 1, do_tpm_init, "", ""), @@ -152,6 +189,7 @@ static cmd_tbl_t tpm2_commands[] = { U_BOOT_CMD_MKENT(clear, 0, 1, do_tpm2_clear, "", ""), U_BOOT_CMD_MKENT(pcr_extend, 0, 1, do_tpm2_pcr_extend, "", ""), U_BOOT_CMD_MKENT(pcr_read, 0, 1, do_tpm_pcr_read, "", ""), + U_BOOT_CMD_MKENT(get_capability, 0, 1, do_tpm_get_capability, "", ""), };
cmd_tbl_t *get_tpm_commands(unsigned int *size) @@ -191,4 +229,11 @@ U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm, "Issue a TPMv2.x command", " Read PCR #<pcr> to memory address <digest_addr>.\n" " <pcr>: index of the PCR\n" " <digest_addr>: address to store the a 32-byte SHA256 digest\n" +"get_capability <capability> <property> <addr> <count>\n" +" Read and display <count> entries indexed by <capability>/<property>.\n" +" Values are 4 bytes long and are written at <addr>.\n" +" <capability>: capability\n" +" <property>: property\n" +" <addr>: address to store <count> entries of 4 bytes\n" +" <count>: number of entries to retrieve\n" ); diff --git a/include/tpm-v2.h b/include/tpm-v2.h index b9f36b22ba..618026ce2a 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -177,4 +177,18 @@ u32 tpm2_pcr_extend(u32 index, const uint8_t *digest); u32 tpm2_pcr_read(u32 idx, unsigned int idx_min_sz, void *data, unsigned int *updates);
+/** + * Issue a TPM2_GetCapability command. This implementation is limited + * to query property index that is 4-byte wide. + * + * @capability Partition of capabilities + * @property Further definition of capability, limited to be 4 bytes wide + * @buf Output buffer for capability information + * @prop_count Size of output buffer + * + * @return code of the operation + */ +u32 tpm2_get_capability(u32 capability, u32 property, void *buf, + size_t prop_count); + #endif /* __TPM_V2_H */ diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index a1f1dbc3d6..330844ee31 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -157,3 +157,36 @@ u32 tpm2_pcr_read(u32 idx, unsigned int idx_min_sz, void *data,
return 0; } + +u32 tpm2_get_capability(u32 capability, u32 property, void *buf, + size_t prop_count) +{ + u8 command_v2[COMMAND_BUFFER_SIZE] = { + tpm_u16(TPM2_ST_NO_SESSIONS), /* TAG */ + tpm_u32(22), /* Length */ + tpm_u32(TPM2_CC_GET_CAPABILITY), /* Command code */ + + tpm_u32(capability), /* Capability */ + tpm_u32(property), /* Property */ + tpm_u32(prop_count), /* Property count */ + }; + u8 response[COMMAND_BUFFER_SIZE]; + size_t response_len = COMMAND_BUFFER_SIZE; + unsigned int properties_off; + int ret; + + ret = tpm_sendrecv_command(command_v2, response, &response_len); + if (ret) + return ret; + + /* + * In the response buffer, the properties are located after the: + * tag (u16), response size (u32), response code (u32), + * YES/NO flag (u8), TPM_CAP (u32) and TPMU_CAPABILITIES (u32). + */ + properties_off = sizeof(u16) + sizeof(u32) + sizeof(u32) + + sizeof(u8) + sizeof(u32) + sizeof(u32); + memcpy(buf, &response[properties_off], response_len - properties_off); + + return 0; +}