[tboot-devel] [PATCH] Update tboot-into.txt information on logging usage

[Ross P. <Ros...@ci...>]

Patch for TBOOT logging enhancements usage information in
tboot-info.txt.

Signed-off-by: Ross Philipson <ros...@ci...>

diff -Nur a/tboot/common/early_printk.c b/tboot/common/early_printk.c
diff -Nur b/docs/tboot-info.txt c/docs/tboot-info.txt
--- b/docs/tboot-info.txt	2008-11-20 10:43:33.000000000 -0500
+++ c/docs/tboot-info.txt	2008-11-20 12:43:52.000000000 -0500
@@ -87,12 +87,33 @@
        http://lkml.org/lkml/2008/10/7/442
        http://lkml.org/lkml/2008/10/7/445
 
-o  Progress of the launch process is indicated via debug printk's to
-   COM1 (hardcoded).  These appear before the normal "(XEN)" output and
are
-   prefixed by "TBOOT:".  Though tboot does initialize the COM port, it
is
-   best if this is also done by GRUB - grub.conf should have:
-       serial --speed=115200 --unit=0
-       terminal console serial
+o  Progress of the launch process is indicated via debug printk's using
three
+   different logging methods:
+       serial - logging is traced over a COM/serial port to a remote
console
+       vga - logging is traced to the local screen
+       memory - logging is traced to a memory location
+   
+   These three methods are not mutually exclusive - any combination can
be
+   enabled. Logging is enabled with command line parameters to tboot.
The first 
+   parameter enables or disables all logging (note that the default is
all):
+       loglvl=all|none
+   
+   The next paramter is used to configure the various logging targets;
any 
+   combination can be used (note that when the parameter is not set,
serial 
+   is the default):
+       logging=vga,serial,memory
+   
+   If serial logging is set, a third parameter can be used to configure
the
+   serial port settings. All of the options beyond baud rate are
optional:
+       serial=baud[/clock_hz][,DPS[,io_base]]
+   
+   The clock_hz allows setting different crystal frequencies, DPS sets
the
+   data/parity/stop bits, and io_base sets the IO port for the device.
The
+   baud rate can also be set to "auto" allowing any current settings
for the
+   serial port to be left intact (e.g. if the serial port has already
been
+   configured by grub). If this parameter is omitted the default is 
+   effectively the following for a legacy PC COM1:
+       serial=115200/115200,8n1,0x3f8
 
 o  tboot will attempt to seal the module measurements using the TPM so
that if
    it is put into S3 it can restore the correct PCR values on resume.
In order