Re: [Qemu-devel] GDB debugging of QEMU.

[Yaodong Yang]

Hello Peter,

Best,

Yaodong

----------------------------------------------

Yaodong Yang

Ph.D. Student

Department of Computer Science & Engineering

University of Nebraska-Lincoln 

Email: address@hidden OR address@hidden

On Aug 9, 2013, at 11:56 AM, Peter Maydell <address@hidden> wrote:

On 9 August 2013 17:45, Yaodong Yang <address@hidden> wrote:

I tried the following commands.

./configure --enable-debug --disable-werror --enable-kvm
--prefix=/usr/local/kvm

--disable-werror is usually not a good idea for developers.

I see, I will get rid of it in my development.

make -j4

sudo make install

gdb sudo /usr/local/kvm/bin/qemu-system/x86_64 -s -enable-kvm -hda
ubuntu.img -m 1024.

Why are you running qemu as root here? (ie why 'sudo'?)

In my implementation, I need to read and write to other raw disks, so I think I need the root permission to run this program. 

Could someone give me some guidance on how to use gdb in QEMU.
I know the basic usage of gdb for simple .c file, but I really
do not know how to use it in QEMU.

There is no particular difference. QEMU is a bigger program
but has no particular gotchas for being debugged.

I think I did not make my question clear. I do not know 1. how to add "-g" flag when compile QEMU, in order to use gdb 2. how to invoke QEMU with gdb, because my previous attempt failed. "gdb sudo /usr/local/kvm/bin/qemu-system/x86_64 -s -enable-kvm -hda"

by the way, when I add storagemanager.c and storagemanager.h to the root directory, in order to compile and link them, I add storagemanger.o in Makefile.objs, as "block-obj-y += nbd.o  block.o  storagemanager.o" in line 10. 

Thanks a lot!

-- PMM