Changes between Version 16 and Version 17 of tpm

Timestamp:

10/30/2026 11:50:55 PM (3 hours ago)

Author:

Tim Harvey

Comment:

added TPM troubleshooting section

tpm

@@ -337 +337 @@
 Many high-security environments actually prefer this method over factory-provisioned certificates. In this case, you won't be relying on certificates from Microchip and you have more strict control. You can also potentially embed more custom metadata into the certificate. 
 
+== Troubleshooting
+
+Note that unless you properly initialize the TPM in U-Boot with 'tpm init && tpm startup TPM2_SU_CLEAR' you may see errors from the Linux TPM stack such as:
+{{{#!bash
+tpm tpm0: A TPM error (256) occurred attempting the self test
+tpm tpm0: invalid TPM_STS.x 0xff, dumping stack for forensics
+tpm tpm0: Operation Timed out
+}}}
+ - This is not an issue unless you are planning on using the TPM in Linux
+
+Note that unless you properly initialize the TPM in U-Boot on some platforms without a RNG source you may see the following when booting Linux:
+{{{#!bash
+tpm-rng tpm-rng: dm_rng_read failed: 256
+WARNING: could not set kaslr-seed
+}}}
+ - This is not an issue unless you are relying on the kalsr-seed to be present in Linux
+
+
 == Additional Resources
  * Gateworks Venice Secure Boot Wiki:  [wiki:venice/secure_boot Gateworks TPM Wiki when used with Secure Boot]