Debugging Standalone Application on Microblaze using QEMU
Table of Contents
Hello World Application. The recommended flow is to use QEMU via the Petalinux tool, however, users can use the DeviceTree Generator (DTG), and DeviceTree Compiler
from github to do this manually. It is this flow that is discussed here.
Creating the Hardware
User can create the design using the Vivado IP Integrator tool (see related links). Export to SDK, to create the HDF file.This HDF file is to be used to create the devicetree that is used in QEMU
Creating the devicetree
Xilinx provide a devicetree generator (DTG) to create devicetree from a HDF fileDownload the devicetree generator (DTG)
- mkdir repo/my_dt
- cd repo/my_dt
- git clone https://github.com/Xilinx/device-tree-xlnx
- cd device-tree-xlnx
- git checkout xilinx-v2017.1
If not, users can add this as shown below:
lmb_bram: memory@0 { device_type = "memory"; reg = < 0x0 0x10000000 >; } ;
memory = <&&lmb_bram>;
model = "microblaze,8.40.b"; version = "8.40.b";
Create the DTS
- launch HSI, source the TCL file below and run the command gen_dtb <HDF FILE>.hdf
proc gen_dtb {hdf} { open_hw_design $hdf set_repo_path ./repo create_sw_design device-tree -os device_tree -proc microblaze_0 generate_target -dir my_dts }
- Exit HSI
Download devicetree compiler (DTC)
- git clone https://git.kernel.org/pub/scm/utils/dtc/dtc.git
- cd dtc
- make
- export PATH=$PATH:/<path to dtc>/dtc
- make sure that you can call the dtc -help
Create the DTB
- dtc -I dts -O dtb -o my_dts/system-top.dtb my_dts/system-top.dts
Launching QEMU
qemu-system-microblazeel -M microblaze-fdt-plnx -m 256 -serial mon:stdio -device loader,file=mb_bootloop_le.elf -gdb tcp::1137 -hw-dtb my_dts/system-top.dtb -display none
Launching debugger and connecting to QEMU
Currently, the XSDB debugger does not support the Microblaze via QEMU. Users, can use the GDB debugger.Users can connect to the debugger using the target remote: <port> command
Since the Microblaze is configured to use Little Endian (this is hard-coded in the Microblaze config), then we must tell the debugger this.
Load the ELF, and symbol info and then user is ready to debug.
Here, we can see the output on the serial port:
Type Ctrl A + x to terminate the QEMU