tpm: add TPM2_GetCapability command support

[platform/kernel/u-boot.git] / lib / tpm-v2.c

diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 7d3834c..08e3ba7 100644 (file)
--- 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;
+}