From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keith Owens To: Dan Malek cc: linuxppc-dev@lists.linuxppc.org Subject: Re: SGI XFS on ppc In-reply-to: Your message of "Sun, 30 Jul 2000 21:20:38 -0400." <3984D466.E3EAB9F0@embeddededge.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 31 Jul 2000 12:02:25 +1000 Message-ID: <13459.965008945@ocs3.ocs-net> Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Sun, 30 Jul 2000 21:20:38 -0400, Dan Malek wrote: >Keith Owens wrote: > >> ..... It should only be >> included if you select kdb but kdb has not been ported to ppc. I >> maintain modutils, kallsyms and kdb. > > >Ummm...I use kgdb and xmon on ppc, at least the ones with serial >ports. Is there yet another debugger for the kernel? kgdb uses the remote gdb interface to debug the kernel and is very useful provided the kernel is actually running. The problem with remote gdb is that it needs some support from the remote kernel for things like page I/O. If the cpu gets into a spin loop when interrupts are disabled then you cannot access gdb to debug it. Also things like single step do not work work when interrupts are disabled. However gdb is very useful for debugging the higher layers of the kernel. kdb is a really low level debugger, it can be used in interrupts and has hooks to detects runaway spin loops and drop into the debugger. It requires no kernel support, it accesses the I/O hardware itself. The downside of kdb is you do not get the nice symbol printing that gdb can do. kdb knows where all the symbols are and can convert addresses to symbols and offsets, but it cannot do source line listing nor do pretty prints of structures. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/