Hi, (Apologies if this is a repost. I sent an earlier, similar mail to this list but I think it got dropped.)
I'm trying to setup kernel debugging for my Pandaboard, which has a TI OMAP4460 (ARMv7 ISA/ dual-core Cortex A9). I'm able to do an "echo g > /proc/sysrq-trigger" and have gdb connect to the target board over a USB to serial cable, view backtraces, set and stop at breakpoints; but as soon as I try to single step, the session hangs. Even nexti, stepi etc hang. I'm able to do a "finish" though. The target is running Ubuntu, kernel 2.6.38-1209-omap4: Linux 2.6.38-1209-omap4 #16 SMP PREEMPT Sat Nov 5 15:53:03 CDT 2011 armv7l armv7l armv7l GNU/Linux The gdb-version I'm using from the host is 7.3.1, I compiled with support for arm-elf targets: $ sudo ./arm-gdb ./vmlinux-arm GNU gdb (GDB) 7.3.1 This GDB was configured as "--host=x86_64-unknown-linux-gnu --target=arm-elf". Connecting to the target: (gdb) bt #0 kgdb_breakpoint () at /sources/ubuntu-natty/kernel/debug/debug_core.c:959 #1 0xc0325ce4 in __handle_sysrq (key=0x67, check_mask=<optimized out>) at /sources/ubuntu-natty/drivers/tty/sysrq.c:522 #2 0xc0325db4 in write_sysrq_trigger (file=<optimized out>, buf=<optimized out>, count=0x2, ppos=<optimized out>) at /sources/ubuntu-natty/drivers/tty/sysrq.c:870 (...) I turned on "set debug remote 1" just before issuing a single-step command, and here's the spew: (gdb) set debug remote 1 (gdb) n Sending packet: $vCont?#49...Ack Packet received: Packet vCont (verbose-resume) is NOT supported Sending packet: $Hc0#db...Ack Packet received: OK Sending packet: $s#73...Ack Packet received: warning: Invalid remote reply: (...session hangs...) At this point I am able to hit Ctrl-C, and attach to the target again. The target is still at the same instruction as before when I re-attach. Does linux/KGDB have trouble with single stepping this target? Any help would be appreciated. Thanks in advance, Mayank ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d _______________________________________________ Kgdb-bugreport mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
