
AMD Confidential 
User Manual    September 12h, 2008 
152    Chapter 11: Debug Interface  
The  pipe is  not  created  until  the  first  “go” command  will  be  executed.  This  can  be 
achieved by clicking  on the  “go” button followed  by a  click on the  “stop” button.  This 
command sequence will setup the named-pipe.  
If you try to connect the  kernel debugger without setting up the named-pipe as described 
the kernel debugger will return an error message. 
In case you  have difficulties to establish  a connection, or the  connection is unstable, or 
KD has  difficulties to stay  in sync with  the simulated OS.  You can set  a multiplier  to 
delay the baud rate. The  baud rate is normally modeled based on the time  elapsed on the 
simulated system. The si mulated system may be running at  1/100 of normal time which 
will give  longer ti me delays  than the  kernel debugger  can tolerate.  Consequently we 
provide a  way to speed  up the modeled  baud rate by  up to 100  times. For example  to 
delay  the baud  rate  by 1/100th  of  normal you  would  use the  following  automation 
command: 
Serial:1.SetMultiplier 1 
By default, the  multiplier is 100 which  means the modeled rate  is unchanged. The user 
may set it in the  range 1 to 100. When set to 1, the  modeled rate is 100 times faster than 
the baud  rate, so the system  delays will be that  much shorter. See  also Section A.7.10, 
“Serial”, on page 238. 
The following command will connect the kernel debugger to the simulator using a pipe as 
communication channel: 
C:\Program  Files\Debugging  Tools  for  Windows  64- bit\kd  –k 
com:pipe,port=\\.\pipe\SimNow.Com1 
We recommend not starting the kernel debugger too  early. To achieve best results launch 
the  kernel debugger  after  the O/S  kernel  has loaded  and  it  is trying  to  establish a 
connection with the kernel debugger. 
11.2 GDB Interface Getting the gdb  interface in the simulator  to work involves a  sequence of commands in 
both the  simulator  and gdb.  The current  implementation requires  the simulator  to be 
started and told to  be ready for gdb to  connect and then having gdb connect.  As long as 
the gdb command, "target remote ..." is issued last, the interface should be established.  
It has  been observed  that after shutting  down the  simulator, the  port used by  the gdb 
interface may not become immediately available for reuse. If this happens  just shut down 
both the simualtor and gdb and start again and the problem should go away. 
11.2.1 Simple Approach
This assumes you are running the simulator and gdb on the same machine.  
 Start the simualtor