10.09.2019. 11.57, "Libo Zhou" <zhl...@foxmail.com> је написао/ла: > > Hi Alex, > > gdb says remote 'g' packet reply is too long, and then prints out a long string of zeros and some other digits sparsely. > > I have tried a lot of combinations of flags but I just can't get it running properly. Do you know what is causing this error? >
This is a known bug, actually in gdb, but there is a workaround is to rollback a commit made around a year ago in QEMU, about 64-bit FPU Mips registers. Or you can fix the buffer size in gdb. Aleksandar > Cheers, > Libo > > > ------------------ Original ------------------ > From: "Alex Bennée";<alex.ben...@linaro.org>; > Send time: Friday, Sep 6, 2019 5:19 PM > To: "Libo Zhou"<zhl...@foxmail.com>; > Cc: "qemu-devel"<qemu-devel@nongnu.org>; "Aleksandar Markovic"< aleksandar.m.m...@gmail.com>; > Subject: Re: [Qemu-devel] QEMU as ISS (Instruction Set Simulator) > > > Libo Zhou <zhl...@foxmail.com> writes: > > > Hi Alex, > > > > > > I just need to log the registers and memory after the program finishes > > its execution. Is it possible to add this functionality myself? > > You'll need to set some sort of breakpoint on the last instruction so > gdb can inspect things before the program is unloaded. I think it's > possible to wire poweroff events to the gdbstub but I haven't looked > into that myself. > > > As for the GDB option, can you tell me the specific steps to do that? I've tried it myself but I had no luck getting it running due to me being new to all this. > > > > For linux-user: > > $QEMU -g 1234 $PRG > > for system emulation > > $QEMU -s -S > > and then on the gdb end: > > gdb $BIN -ex "target remote localhost:1234" > > and then you can operate as you normally do with a gdb session. GDB has > two scripting interfaces. The command mode is basically a list of gdb > commands but might work for what you want. If you want to be a bit more > programatic you can use python. See the example in > tests/guest-debug/test-gdbstub.py > > > > > Thanks, > > Libo > > > > > > > > ------------------ Original ------------------ > > From: "Alex Bennée";<alex.ben...@linaro.org>; > > Send time: Thursday, Sep 5, 2019 8:58 PM > > To: "qemu-devel"<qemu-devel@nongnu.org>; > > Cc: "Aleksandar Markovic"<aleksandar.m.m...@gmail.com>; > > Subject: Re: [Qemu-devel] QEMU as ISS (Instruction Set Simulator) > > > > > > > > > > Libo Zhou <zhl...@foxmail.com> writes: > > > >> Do you know where in the source file I should look into to add my custom logging functionality? > >> > >> > >> Or, would you suggest using gdb to look at my target register and memory contents? The answer in this link below looks really promising. I'm gonna give it a try first. > >> > >> https://stackoverflow.com/questions/39503997/how-to-run-a-single-line-of-assembly-then-see-r1-and-condition-flags > > > > The gdbstub should allow you do full introspection and adding > > additional registers is fairly easy, see FOO_gdb_[set|get]_reg helpers > > in the appropriate target/FOO directories. > > > >> However, if I am able to customize log, it will be super convenient. > > > > So you want something above what -d cpu will show you? > > > >> > >> > >> > >> Cheers, > >> > >> Libo > >> > >> > >> > >> ------------------ Original ------------------ > >> From: "Aleksandar Markovic";<aleksandar.m.m...@gmail.com>; > >> Send time: Thursday, Sep 5, 2019 6:54 PM > >> To: "Libo Zhou"<zhl...@foxmail.com>; > >> Cc: "qemu-devel"<qemu-devel@nongnu.org>; > >> Subject: Re: [Qemu-devel] QEMU as ISS (Instruction Set Simulator) > >> > >> > >> > >> 04.09.2019. 05.23, "Libo Zhou" <zhl...@foxmail.com> ?е написао/ла: > >>> > >>> Hi Aleksandar, > >>> > >>> I have spent some time looking at your MXU ASE patch. It's super helpful. > >> I need to do exactly the same thing as you did. > >>> > >>> Now I just need a way to observe the memory and register file contents to > >> debug my instruction set simulator. I played with the "-d" switch to log a > >> bunch of information, but it seems that none of the items is of my > >> interest. The "-d cpu_reset" option displays all zeros in the GPR log. > >>> > >> > >> It looks you need a custom logging tailored to your needs, based on > >> intercepting the instructions you added. > >> > >> Aleksandar > >> > >>> Please take your time, as I fully understand you need to work on Qemu > >> while answering all my questions. Again, thank you very much for your help! > >>> > >>> Cheers, > >>> Libo > >>> > > > -- > Alex Bennée
