✎ soc:2008:dverkamp:journal:week8

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.

====== Daniel Verkamp: COMBOOT Support ======

===== Journal =====

==== Week 8 ====
----

=== 15-17 July 2008 ===

  * After a conversation with mcb30 last Thursday on how to fix the problems with COM32 stack overwrites during image loading, I've implemented his suggestions.  This resulted in a 3-day debugging marathon until I switched to a simpler test case and just single stepped through the entire image execution process... and finally noticed (thanks to the Intel-syntax Bochs debugger) that I had written a constant as 12 instead of $12 (AT&T syntax strikes again :-)).  But the upshot of all this is that COM32 programs using "Run kernel image" work totally correctly now, without any hack to limit the stack size, and I can say without reservation that menu.c32 is working perfectly fine now (given the configuration filename via the command line); it can load itself numerous times (until there is no more memory left to load the image again) as well as other image types without any problems now.  I plan to start doing further testing on real hardware with various booting scenarios now, but so far, everything looks good.

=== 18 July ===

  * Added a jmp to self-modifying intcall code to avoid problems on 486 (makes execution in qemu much faster too) [[ http://git.etherboot.org/?p=people/dverkamp/gpxe.git;a=commitdiff;h=3d6bd95bcb0919c4c14df0a1bce3641388f6d88d | 3d6bd95bcb0919c4c14df0a1bce3641388f6d88d ]]

Since menu.c32 is working well now, here is a sample SYSLINUX menu I am using to test (http://10.0.0.11 is a web server):

<code>
default menu.c32
prompt 0
menu title gPXE COMBOOT menu test

timeout 600

label tomsrtbt
  menu label tomsrtbt
  menu default
  kernel http://10.0.0.11/~daniel/gpxe/gtest/bz2bzImage
  append initrd=http://10.0.0.11/~daniel/gpxe/gtest/initrd.bz2 root=100

label gtest
  menu label tomsrtbt via gtest.gpxe
  kernel http://10.0.0.11/~daniel/gpxe/gtest.gpxe

label tube
  menu label tube
  kernel http://10.0.0.11/~daniel/gpxe/TUBE.COM
</code>

Trace: • week2 • week3 • week10 • week4 • week12 • rpcbind_-_build_instructions • bkodebian • week4 • week2 • windows_7_install_to_iscsi • week11 • weekb • week5 • week2 • pravin • cooldavid • week4 • week6 • week8 • weeka