[SeaBIOS] [Question] Debug Seabios by GDB with Qemu
kevin at koconnor.net
Thu Feb 8 03:39:40 CET 2018
On Mon, Feb 05, 2018 at 07:10:58PM +0800, Liu, Jing2 wrote:
> On 1/31/2018 10:46 AM, Kevin O'Connor wrote:
> > On Mon, Jan 29, 2018 at 02:18:45PM +0800, Liu, Jing2 wrote:
> > > Hello,
> > >
> > > I am using Seabios for qemu startup, and interested in the debugging by GDB
> > > to see how the bios works.
> > >
> > > Currently, I do it as https://www.seabios.org/Debugging said but met some
> > > problems so that couldn't move on. :(
> > > Could someone give some pointers on what I missed or have to do to enable
> > > the gdb debugging?
> > >
> > > Note:
> > > Arch: x86_64 PC
> > > CONFIG_DEBUG_SERIAL is enabled.
> > > CONFIG_RELOCATE_INIT is disabled.
> > >
> > > 1. After Qemu starts, I run "gdb out/rom32seg.o" in another session, and do
> > > "target remote localhost:1234", it warns me that
> > > "Selected architecture i386 is not compatible with reported target
> > > architecture i386:x86_64". But I didn't find any 64bit rom.
> > I'm not sure why you choose out/rom32seg.o - to debug the 32bit code,
> > you want to use out/rom.o.
> Thank you for your answer!
> But after I connect to qemu in the gdb session, and execute "run" OR "start"
> to start the rom.o, it both reports me a signal SIGKILL.
It works for me. See log below.
$ ../qemu/qemu-2.10.0/i386-softmmu/qemu-system-i386 -k en-us -snapshot -L test -chardev stdio,id=seabios -device isa-debugcon,iobase=0x402,chardev=seabios -m 512 -hda dos-drivec -s -S
$ gdb out/rom.o
GNU gdb (GDB) Fedora 8.0.1-35.fc27
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Reading symbols from out/rom.o...done.
(gdb) target remote localhost:1234
Remote debugging using localhost:1234
0x0000fff0 in ?? ()
(gdb) b startBoot
Breakpoint 1 at 0xf1d4d: file ./src/post.c, line 184.
Breakpoint 1, startBoot () at ./src/post.c:184
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