KGDB Question

Jason Hanna jason.m.hanna.at.coincident at gmail.com
Thu Nov 6 16:40:16 EST 2008


Hi All,

Sorry for the newb questions, but I'm trying to setup KGDB for my
embedded development environment and I'm slightly confused.

Compiling a 2.6.27.3 kernel for a Kilauea (PowerPC 405EX) development
board. U-boot 1.3.2 on target and ELDK 4.2 cross-tools on Debian
(Lenny) host. Everything works fine w/regard to cross-compiling,
booting, etc.

Now trying to configure KGDB so I can do some kernel/driver coding and
debugging. Have enabled KGDB and DEBUG_INFO config options and
re-compiled my target kernel. Here's where I start to get confused:

1.) When configuring the kernel should I be seeing I/O driver options
for serial or ethernet ports? I don't. Looking at some older examples
online it seems there were options for selecting a serial port or
ethernet during kernel config. Reading the KGDB DocBook (Ch 2) leads
me to believe I should see some I/O driver options.

2.) Tried setting "kgdboc=ttyS0,115200" and "kgdbwait" (in that order)
as boot args in U-Boot. Boot begins and pauses after kernel and device
tree are loaded. Attempting to run "target remote /dev/ttyS0" on my
host and getting: Ignoring packet error, continuing...(3 times) and
Malformed response to offset query, timeout. Pretty sure I've got
everything connected correctly, but back to item #1 not sure I'm
missing an I/O driver or have some other issue?

3.) What is the status of KGDB in the 2.6.27 tree? It seems to have
been added to the kernel in previous versions, but I can't tell if
it's complete and working properly for my architecture. Should I be
attempting to use the patch from the KGDB sourceforge project?

Thanks,
-jmh



More information about the Linuxppc-dev mailing list