Daniel Verkamp: COMBOOT Support

Journal

Did some more debugging on the real hardware initrd loading problem I was having earlier; Stefan walked me through setting up the GDB stub (had to build a CVS version of GDB to get working breakpoints, and for some reason remotebaud defaults to the ridiculous 4294967295 rather than something sensible, like the 115200 that gPXE uses). Didn't figure anything new out with this, although it looks like the GDB stub could be very useful in the future. After that, tried building with DEBUG=bzimage, and uncovered some interesting differences in the length of the initrd segment and other bzimage debug output; sent a mail to etherboot-developers with details.

Worked on INT 22h AX=16h (Run kernel image), but ran into what seems to be a GCC bug; spent a lot of time trying to figure out why adding an (unexecuted) case to a switch caused other cases to misbehave. The bug seems to appear in GCC 4.3.1 and GCC 4.2.4 but not GCC 4.1.1. It also only occurs when the file in question is built with DEBUG, so I figured out how to add a Makefile rule for .s for debug objects.

Trace: • week5