path: root/Documentation
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authorRajiv Andrade <srajiv@linux.vnet.ibm.com>2010-03-25 00:55:32 -0300
committerJames Morris <jmorris@namei.org>2010-03-26 09:30:03 +1100
commit225a9be24d799aa16d543c31fb09f0c9ed1d9caa (patch)
treee2db049524c7f153457e55506d1ef4cec0ccf39c /Documentation
parent310de047eef6685274045db1e6b39c9f313df428 (diff)
TPM: workaround to enforce PCR updates across suspends
Add a workaround for TPM's which fail to flush last written PCR values in a TPM_SaveState, in preparation for suspend. Signed-off-by: David Safford <safford@watson.ibm.com> Acked-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'Documentation')
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d80930d58da..e0df679c390 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -99,6 +99,7 @@ parameter is applicable:
SWSUSP Software suspend (hibernation) is enabled.
SUSPEND System suspend states are enabled.
FTRACE Function tracing enabled.
+ TPM TPM drivers are enabled.
TS Appropriate touchscreen support is enabled.
UMS USB Mass Storage support is enabled.
USB USB support is enabled.
@@ -2619,6 +2620,15 @@ and is between 256 and 4096 characters. It is defined in the file
tp720= [HW,PS2]
+ tpm_suspend_pcr=[HW,TPM]
+ Format: integer pcr id
+ Specify that at suspend time, the tpm driver
+ should extend the specified pcr with zeros,
+ as a workaround for some chips which fail to
+ flush the last written pcr on TPM_SaveState.
+ This will guarantee that all the other pcrs
+ are saved.
[FTRACE] will set tracing buffer size.