From: Gang Wei <gang.wei@in...> - 2012-01-05 15:15:29
changeset 73be7eddb9e1 in /var/www/tboot.hg
update README for mwait AP wakeup mechanism
BTW, updated the tboot start address according to recent changes for GRUB2.
Signed-off-by: Gang Wei <gang.wei@...>
README | 18 ++++++++++++++++--
1 files changed, 16 insertions(+), 2 deletions(-)
diffs (38 lines):
diff -r 7c7c0b309004 -r 73be7eddb9e1 README
--- a/README Sat Dec 31 17:37:22 2011 +0800
+++ b/README Thu Jan 05 23:11:04 2012 +0800
@@ -150,6 +150,19 @@
will continue the boot. However, for 'continue' or 'halt' policy types,
tboot will halt the boot.
+o tboot provides a better AP wakeup mechanism based on cpu MWAIT feature for
+ OS/VMM. This mechanism is defaultly disabled, and could be enabled with
+ tboot command line option:
+ Once this mechanism is enabled, system will boot faster and will NOT require
+ VT to be enabled. But before enabling this option, please make sure the
+ OS/VMM has already support it, otherwise system can never boot up. Confirm
+ it via finding lines like below in the OS/VMM booting log:
+ TBOOT: found shared page at ....
+ flags: 0x0000000x
@@ -184,11 +197,12 @@
measured launch fails for any reason.
o Tboot is always built 32bit and runs in protected mode without PAE or
- paging enabled. Tboot loads and executes at 0x803000 (8MB).
+ paging enabled. Tboot loads and executes at 0x800000 (8MB).
o The code requires that VT be enabled as well as TXT. This is because
the mechanism for bringing up the APs uses VMX to create a mini-VM in
- order to trap on INIT-SIPI-SIPI.
+ order to trap on INIT-SIPI-SIPI. If OS/VMM support tboot's new AP wakeup
+ mechanism based on MWAIT, then VT is not required to be enabled.
o The tools/txt-stat project is a Linux application that reads some of
the TXT registers and will display the tboot boot log if tboot was run
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