Re: QNX VM hang on Qemu

["Alex Bennée" <alex.bennee@linaro.org>]

Faiq Ali Sayed <faiqueali.109@gmail.com> writes:

> Alex thanks for the reply,
>
> I don't know what the debug symbol is, but my target system is QNX aarch64 
> below are the configuration of GDB,
>
> (gdb) show configuration
> This GDB was configured as follows:
>    configure --host=x86_64-pc-linux-gnu --target=aarch64-unknown-nto-qnx7.1.0
>              --with-auto-load-dir=$debugdir:$datadir/auto-load
>              --with-auto-load-safe-path=$debugdir:$datadir/auto-load
>              --without-expat
>              --with-gdb-datadir=/opt/qnx710/host/linux/x86_64/usr/share/gdb (relocatable)
>              --with-jit-reader-dir=/opt/qnx710/host/linux/x86_64/usr/lib/gdb (relocatable)
>              --without-libunwind-ia64
>              --without-lzma
>              --without-babeltrace
>              --without-intel-pt
>              --disable-libmcheck
>              --without-mpfr
>              --with-python=/opt/qnx710/host/linux/x86_64/usr (relocatable)
>              --without-guile
>              --with-separate-debug-dir=/opt/qnx710/host/linux/x86_64/usr/lib/debug (relocatable)
>              --with-sysroot=/opt/qnx710/target/qnx7/aarch64
>
> while I got the below result, after executing the x/10i $pc 
>
> (gdb) x/10i $pc
> => 0x100000: .inst 0x5371242b ; undefined
>    0x100004: fcmla v21.8h, v3.8h, v16.h[1], #270
>    0x100008: .inst 0x64657472 ; undefined
>    0x10000c: ldnp d26, d27, [x9, #-176]
>    0x100010: .inst 0x72706974 ; undefined
>    0x100014: .inst 0x7365636f ; undefined
>    0x100018: .inst 0x733b2b73 ; undefined
>    0x10001c: fnmls z23.h, p0/m, z19.h, z18.h
>    0x100020: .inst 0x3b2b6b61 ; undefined
>    0x100024: .inst 0x72627768 ; undefined
>
> Can you please let me know how I can step in ?

step-instruction in gdb, however...

It very much looks like the image you have built doesn't have any
instructions in the correct starting place. It's unsurprising that it
hangs running random undefined instructions. 

> When I press c it does not execute further and hangs..
>
> Faiq
>
> On Tue, Feb 20, 2024 at 3:41 PM Alex Bennée <alex.bennee@linaro.org> wrote:
>
>  Faiq Ali Sayed <faiqueali.109@gmail.com> writes:
>
>  > Hi everyone, 
>  > I am facing an issue during booting QNX VM using Qemu,
>  > I have an image to Boot the VM. and when I trigger a Qemu command to create a VM it is stuck.
>  > I also used a debugger to investigate but I can not see any result by GDB.
>  >
>  > Here is the output of first windows
>  >
>  > qemu-system-aarch64 -M xlnx-zcu102 -m 16G -serial mon:stdio -display none -device
>  > loader,file=QNX-IFS,addr=0x00100000,cpu-num=0 -drive
>  > file=/home/faiq/Downloads/install/BootSD/qemu-boot_sd.img,if=sd,format=raw,index=1 -boot mode=5 -net
>  > nic,model=cadence_gem -net nic,model=cadence_gem -net nic,model=cadence_gem -net
>  > nic,model=cadence_gem,netdev=xzynq0 -netdev user,id=xzynq0,tftp=/tftpboot  -nographic -global
>  > xlnx,zynqmp-boot.cpu-num=0 -global 'xlnx,zynqmp-boot.use-pmufw=true' -s -S
>  >
>  > qemu-system-aarch64: warning: hub 0 is not connected to host network
>
>  Is this QNX VM image built for the xlnx-zcu102 board?
>
>  > on the other hand, here is the output of GDB:
>  >
>  > (gdb) target remote :1234
>  > Remote debugging using :1234
>  > warning: No executable has been specified and target does not support
>  > determining executable automatically.  Try using the "file" command.
>  > 0x0000000000100000 in ?? ()
>  > (gdb) c
>  > Continuing.
>
>  You'll either want the debug symbols for your image or tell GDB what the
>  target arch is. Check you are somewhere sane by doing:
>
>    x/10i $pc
>
>  and step through the instructions and see where it goes. If you hit
>  Ctrl-C are you executing nonsense instructions or in a tight loop
>  hanging?
>
>  -- 
>  Alex Bennée
>  Virtualisation Tech Lead @ Linaro

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro