A following patch introduces EFI_TCG2_PROTOCOL. One of the functions of that protocol is GetCapability(). In order to parse device capabilities we need to access a u32 before the properties which the current implementation ignores while reading device properties.
So let's make the response length configurable and prepare the functions for EFI_TCG2_PROTOCOL.
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org --- cmd/tpm-v2.c | 2 +- include/tpm-v2.h | 12 +++++++----- lib/tpm-v2.c | 10 +++++++--- 3 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c index e6742656f578..c2df1c34043a 100644 --- a/cmd/tpm-v2.c +++ b/cmd/tpm-v2.c @@ -183,7 +183,7 @@ static int do_tpm_get_capability(struct cmd_tbl *cmdtp, int flag, int argc, data = map_sysmem(simple_strtoul(argv[3], NULL, 0), 0); count = simple_strtoul(argv[4], NULL, 0);
- rc = tpm2_get_capability(dev, capability, property, data, count); + rc = tpm2_get_capability(dev, capability, property, data, count, false); if (rc) goto unmap_data;
diff --git a/include/tpm-v2.h b/include/tpm-v2.h index f6c045d35480..ee74028ca83b 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -257,15 +257,17 @@ u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, * to query property index that is 4-byte wide. * * @dev TPM device - * @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 + * @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 + * @get_count Include tpmu property count * * @return code of the operation */ u32 tpm2_get_capability(struct udevice *dev, u32 capability, u32 property, - void *buf, size_t prop_count); + void *buf, size_t prop_count, bool get_count);
/** * Issue a TPM2_DictionaryAttackLockReset command. diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index a4c352e3ef75..b58c1057995b 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -161,7 +161,7 @@ u32 tpm2_pcr_read(struct udevice *dev, u32 idx, unsigned int idx_min_sz, }
u32 tpm2_get_capability(struct udevice *dev, u32 capability, u32 property, - void *buf, size_t prop_count) + void *buf, size_t prop_count, bool get_count) { u8 command_v2[COMMAND_BUFFER_SIZE] = { tpm_u16(TPM2_ST_NO_SESSIONS), /* TAG */ @@ -181,13 +181,17 @@ u32 tpm2_get_capability(struct udevice *dev, u32 capability, u32 property, if (ret) return ret;
+ /* When reading PCR properties we need the count */ + properties_off = sizeof(u16) + sizeof(u32) + sizeof(u32) + + sizeof(u8) + sizeof(u32); /* * 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); + if (!get_count) + properties_off += sizeof(u32); + memcpy(buf, &response[properties_off], response_len - properties_off);
return 0;