From 622c6b84ab029a366dd09740a24d36ae9fad697f Mon Sep 17 00:00:00 2001 From: dnojiri Date: Fri, 3 Apr 2020 10:51:50 -0700 Subject: TPM: Add tlcl_cr50_get_boot_mode tlcl_cr50_get_boot_mode gets the boot mode from Cr50. The boot mode tells coreboot/depthcharge whether booting the kernel is allowed or not. BUG=b:147298634, chromium:1045217, b:148259137 BRANCH=none TEST=Verify software sync succeeds on Puff. Signed-off-by: dnojiri Change-Id: Iadae848c4bf315f2131ff6aebcb35938307b5db4 Reviewed-on: https://review.coreboot.org/c/coreboot/+/40388 Reviewed-by: Julius Werner Reviewed-by: Christian Walter Tested-by: build bot (Jenkins) --- src/security/tpm/tss/tcg-2.0/tss_marshaling.c | 5 +++++ src/security/tpm/tss/tcg-2.0/tss_structures.h | 1 + src/security/tpm/tss/vendor/cr50/cr50.c | 25 +++++++++++++++++++++++++ src/security/tpm/tss/vendor/cr50/cr50.h | 9 +++++++++ 4 files changed, 40 insertions(+) diff --git a/src/security/tpm/tss/tcg-2.0/tss_marshaling.c b/src/security/tpm/tss/tcg-2.0/tss_marshaling.c index 45ade1a314..a229dd17ef 100644 --- a/src/security/tpm/tss/tcg-2.0/tss_marshaling.c +++ b/src/security/tpm/tss/tcg-2.0/tss_marshaling.c @@ -335,6 +335,9 @@ static int marshal_cr50_vendor_command(struct obuf *ob, void *command_body) */ rc |= obuf_write_be16(ob, *sub_command); break; + case TPM2_CR50_SUB_CMD_GET_BOOT_MODE: + rc |= obuf_write_be16(ob, *sub_command); + break; default: /* Unsupported subcommand. */ printk(BIOS_WARNING, "Unsupported cr50 subcommand: 0x%04x\n", @@ -560,6 +563,8 @@ static int unmarshal_vendor_command(struct ibuf *ib, return ibuf_read_be8(ib, &vcr->recovery_button_state); case TPM2_CR50_SUB_CMD_TPM_MODE: return ibuf_read_be8(ib, &vcr->tpm_mode); + case TPM2_CR50_SUB_CMD_GET_BOOT_MODE: + return ibuf_read_be8(ib, &vcr->boot_mode); default: printk(BIOS_ERR, "%s:%d - unsupported vendor command %#04x!\n", diff --git a/src/security/tpm/tss/tcg-2.0/tss_structures.h b/src/security/tpm/tss/tcg-2.0/tss_structures.h index ade9b27873..3f0c6545ab 100644 --- a/src/security/tpm/tss/tcg-2.0/tss_structures.h +++ b/src/security/tpm/tss/tcg-2.0/tss_structures.h @@ -349,6 +349,7 @@ struct vendor_command_response { uint8_t num_restored_headers; uint8_t recovery_button_state; uint8_t tpm_mode; + uint8_t boot_mode; }; }; diff --git a/src/security/tpm/tss/vendor/cr50/cr50.c b/src/security/tpm/tss/vendor/cr50/cr50.c index ec69df4ac9..ae2f7c2516 100644 --- a/src/security/tpm/tss/vendor/cr50/cr50.c +++ b/src/security/tpm/tss/vendor/cr50/cr50.c @@ -107,6 +107,31 @@ uint32_t tlcl_cr50_get_tpm_mode(uint8_t *tpm_mode) return TPM_SUCCESS; } +uint32_t tlcl_cr50_get_boot_mode(uint8_t *boot_mode) +{ + struct tpm2_response *response; + uint16_t mode_command = TPM2_CR50_SUB_CMD_GET_BOOT_MODE; + + printk(BIOS_DEBUG, "Reading cr50 boot mode\n"); + + response = tpm_process_command(TPM2_CR50_VENDOR_COMMAND, &mode_command); + + if (!response) + return TPM_E_IOERROR; + + if (response->hdr.tpm_code == VENDOR_RC_NO_SUCH_COMMAND) + /* Explicitly inform caller when command is not supported */ + return TPM_E_NO_SUCH_COMMAND; + + if (response->hdr.tpm_code) + /* Unexpected return code from Cr50 */ + return TPM_E_IOERROR; + + *boot_mode = response->vcr.boot_mode; + + return TPM_SUCCESS; +} + uint32_t tlcl_cr50_immediate_reset(uint16_t timeout_ms) { struct tpm2_response *response; diff --git a/src/security/tpm/tss/vendor/cr50/cr50.h b/src/security/tpm/tss/vendor/cr50/cr50.h index e3137630de..0f91732856 100644 --- a/src/security/tpm/tss/vendor/cr50/cr50.h +++ b/src/security/tpm/tss/vendor/cr50/cr50.h @@ -15,6 +15,7 @@ #define TPM2_CR50_SUB_CMD_TURN_UPDATE_ON (24) #define TPM2_CR50_SUB_CMD_GET_REC_BTN (29) #define TPM2_CR50_SUB_CMD_TPM_MODE (40) +#define TPM2_CR50_SUB_CMD_GET_BOOT_MODE (52) /* Cr50 vendor-specific error codes. */ #define VENDOR_RC_ERR 0x00000500 @@ -78,6 +79,14 @@ uint32_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state); */ uint32_t tlcl_cr50_get_tpm_mode(uint8_t *tpm_mode); +/** + * CR50 specific TPM command sequence to query the current boot mode. + * + * Returns TPM_SUCCESS if boot mode is successfully retrieved. + * Returns TPM_E_* for errors. + */ +uint32_t tlcl_cr50_get_boot_mode(uint8_t *boot_mode); + /** * CR50 specific TPM command sequence to trigger an immediate reset to the Cr50 * device after the specified timeout in milliseconds. A timeout of zero means -- cgit v1.2.3