Is there any chance you have pulled in the TscTimerLib from the PerformancePkg 
into the X64 part of your build?  If you have, then you need to set the 
following PCD to 0xB000 too.  Its default value is 0x400.

  gPerformancePkgTokenSpaceGuid.PcdPerfPkgAcpiIoPortBaseAddress

Mike
From: Duane Voth [mailto:[email protected]]
Sent: Wednesday, April 10, 2013 3:15 PM
To: Laszlo Ersek
Cc: [email protected]
Subject: Re: [edk2] OVMF networking revisited

Ok, while qemu emulation is not stopped, periodic samples of 0xb008 (using the 
qemu cmd "i/w 0xb008") do indeed return running timer-like values.

AcpiTimerLibConstructor() runs in 32bit mode and uses 0xb0nn values, but at the 
point of my hang the cpu is in 64bit mode and is reading from 0x0408 instead of 
0xb008.  Disassembly shows that 0x0408 is a constant compiled into the source:

   0x3e5576e2:  push   %rbp
   0x3e5576e3:  mov    %rsp,%rbp
   0x3e5576e6:  sub    $0x20,%rsp
   0x3e5576ea:  mov    $0x408,%ecx
   0x3e5576ef:  movabs $0x3e5579fa,%rax
   0x3e5576f9:  callq  *%rax
   0x3e5576fb:  leaveq
   0x3e5576fc:  retq




(this next part of the conversation will move to the new gdb symbol debug 
thread - but I wanted Laszlo to see this last comment/question)

You need the debug symbols for the qemu binary. Your distro may provide them in 
a separate package, or not at all. In the latter case you should rebuild from 
source (with --enable-debug), or rebuild your distro's package with debug 
symbols enabled.

gdb needs qemu *symbols* in order for breakpoints to work?   I thought the 
gdbserver built into qemu would simply provide the proper API over the remote 
link.  I can however see why a released version of qemu would not have 
--enable-debug turned on (disabling breakpointing).

Duane
------------------------------------------------------------------------------
Precog is a next-generation analytics platform capable of advanced
analytics on semi-structured data. The platform includes APIs for building
apps and a phenomenal toolset for data science. Developers can use
our toolset for easy data analysis & visualization. Get a free account!
http://www2.precog.com/precogplatform/slashdotnewsletter
_______________________________________________
edk2-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/edk2-devel

Reply via email to