From e371d421137901043ba495f8e4f5063be26b6764 Mon Sep 17 00:00:00 2001 From: Keith Short Date: Fri, 11 Jan 2019 07:52:32 -0700 Subject: src/security/tpm: query recovery mode from Cr50 On the Sarien/Arcada platforms, the EC is not trusted to provide the state of the ESC+REFRESH+PWR recovery combination. On these platforms the Cr50 latches the state of REFRESH+PWR for use as the recovery mode key combination. BUG=b:122715254 BRANCH=none TEST=Verify recovery mode screen shown after pressing REFRESH+PWR Signed-off-by: Keith Short Change-Id: Ie3ce519956f916023c8c52f1d11fa93331f52f3c Reviewed-on: https://review.coreboot.org/c/30929 Tested-by: build bot (Jenkins) Reviewed-by: Duncan Laurie Reviewed-by: Stefan Reinauer --- 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 | 16 ++++++++++++++++ src/security/tpm/tss/vendor/cr50/cr50.h | 9 +++++++++ 4 files changed, 31 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 49ac5e8979f3..d8b3097962e5 100644 --- a/src/security/tpm/tss/tcg-2.0/tss_marshaling.c +++ b/src/security/tpm/tss/tcg-2.0/tss_marshaling.c @@ -273,6 +273,9 @@ static int marshal_cr50_vendor_command(struct obuf *ob, void *command_body) rc |= obuf_write_be16(ob, sub_command[0]); rc |= obuf_write_be16(ob, sub_command[1]); break; + case TPM2_CR50_SUB_CMD_GET_REC_BTN: + rc |= obuf_write_be16(ob, *sub_command); + break; default: /* Unsupported subcommand. */ printk(BIOS_WARNING, "Unsupported cr50 subcommand: 0x%04x\n", @@ -473,6 +476,8 @@ static int unmarshal_vendor_command(struct ibuf *ib, case TPM2_CR50_SUB_CMD_TURN_UPDATE_ON: return ibuf_read_be8(ib, &vcr->num_restored_headers); break; + case TPM2_CR50_SUB_CMD_GET_REC_BTN: + return ibuf_read_be8(ib, &vcr->recovery_button_state); 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 2bac6337e4b9..6952169108e4 100644 --- a/src/security/tpm/tss/tcg-2.0/tss_structures.h +++ b/src/security/tpm/tss/tcg-2.0/tss_structures.h @@ -297,6 +297,7 @@ struct vendor_command_response { uint16_t vc_subcommand; union { uint8_t num_restored_headers; + uint8_t recovery_button_state; }; }; diff --git a/src/security/tpm/tss/vendor/cr50/cr50.c b/src/security/tpm/tss/vendor/cr50/cr50.c index 90f796379c50..450ad97fe5f3 100644 --- a/src/security/tpm/tss/vendor/cr50/cr50.c +++ b/src/security/tpm/tss/vendor/cr50/cr50.c @@ -52,3 +52,19 @@ uint32_t tlcl_cr50_enable_update(uint16_t timeout_ms, *num_restored_headers = response->vcr.num_restored_headers; return TPM_SUCCESS; } + +uint32_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state) +{ + struct tpm2_response *response; + uint16_t sub_command = TPM2_CR50_SUB_CMD_GET_REC_BTN; + + printk(BIOS_INFO, "Checking cr50 for recovery request\n"); + + response = tpm_process_command(TPM2_CR50_VENDOR_COMMAND, &sub_command); + + if (!response || response->hdr.tpm_code) + return TPM_E_INTERNAL_INCONSISTENCY; + + *recovery_button_state = response->vcr.recovery_button_state; + return TPM_SUCCESS; +} diff --git a/src/security/tpm/tss/vendor/cr50/cr50.h b/src/security/tpm/tss/vendor/cr50/cr50.h index 9bf3bd5f79f6..a1ab539c0730 100644 --- a/src/security/tpm/tss/vendor/cr50/cr50.h +++ b/src/security/tpm/tss/vendor/cr50/cr50.h @@ -25,6 +25,7 @@ #define TPM2_CR50_VENDOR_COMMAND ((TPM_CC)(TPM_CC_VENDOR_BIT_MASK | 0)) #define TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS (21) #define TPM2_CR50_SUB_CMD_TURN_UPDATE_ON (24) +#define TPM2_CR50_SUB_CMD_GET_REC_BTN (29) /** * CR50 specific tpm command to enable nvmem commits before internal timeout @@ -44,4 +45,12 @@ uint32_t tlcl_cr50_enable_nvcommits(void); uint32_t tlcl_cr50_enable_update(uint16_t timeout_ms, uint8_t *num_restored_headers); +/** + * CR50 specific tpm command to get the latched state of the recovery button. + * + * Return value indicates success or failure of accessing the TPM; in case of + * success the recovery button state is saved in recovery_button_state. + */ +uint32_t tlcl_cr50_get_recovery_button(uint8_t *recovery_button_state); + #endif /* CR50_TSS_STRUCTURES_H_ */ -- cgit v1.2.3