Intel® Simics® Simulator for Intel® FPGAs: User Guide

ID 784383
Date 12/04/2023
Public

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6.6. Capturing CPU Instruction Execution Trace

The Intel® Simics® simulator supports the capability to capture a trace with the instructions that the CPUs execute in the target system. This feature is helpful to track the instruction execution path of the target software. You can save the generated trace into a file or view in the console.

To achieve this, you can use the new-tracer-tool command from the Intel® Simics® CLI to create a tracer. If you want to save the trace into a file, this command receives the file name where the tracer logs the information as a parameter. You can also indicate if the trace file must include data memory information, exceptions trace, and if you want to capture the virtual, physical, or linear address of the instruction executed.

Note: When you enable this feature, the performance of the Intel® Simics® simulator is affected negatively.

The following capture shows an example of the use of this command to generate a CPU instructions trace file. Here, the trace file created is named instruction_trace.txt, in which instructions, exceptions, and physical and virtual addresses are logged. The tracer name is tracer1, and the tracer gets connected to all CPUs in the configuration. The log file is created under the project directory by default.

#Intel Simics simulator CLI 
simics> new-tracer-tool "tracer1" instruction_trace.txt -connect-all -trace-instructions -trace-exceptions -print-virtual-address -print-physical-address

Created tracer1 (connected to 4 processors)
simics> !ls instruction_trace.txt
instruction_trace.txt

simics> run 500 cycles

simics> !more instruction_trace.txt
::::::::::::::
instruction_trace.txt
::::::::::::::
inst: [  1] core[0] <v:0x0000000000000000> <p:0x0000000000> 0a 00 00 14   b 0x28
inst: [  2] core[0] <v:0x0000000000000028> <p:0x0000000028> 34 00 00 14   b 0xf8
inst: [  3] core[0] <v:0x00000000000000f8> <p:0x00000000f8> cd ff ff 17   b 0x2c
inst: [  4] core[0] <v:0x000000000000002c> <p:0x000000002c> 41 42 38 d5   mrs x1, currentel
inst: [  5] core[0] <v:0x0000000000000030> <p:0x0000000030> 3f 20 00 f1   cmp x1, #0x8
inst: [  6] core[0] <v:0x0000000000000034> <p:0x0000000034> 6c 00 00 54   b.gt 0x40
inst: [  7] core[0] <v:0x0000000000000040> <p:0x0000000040> 00 11 3e d5   mrs x0, scr_el3
inst: [  8] core[0] <v:0x0000000000000044> <p:0x0000000044> 00 0c 40 b2   orr x0, x0, #0xf
inst: [  9] core[0] <v:0x0000000000000048> <p:0x0000000048> 00 11 1e d5   msr scr_el3, x0
inst: [ 10] core[0] <v:0x000000000000004c> <p:0x000000004c> 5f 11 1e d5   msr cptr_el3, xzr
inst: [ 11] core[0] <v:0x0000000000000050> <p:0x0000000050> 0a 00 00 14   b 0x78
inst: [ 12] core[0] <v:0x0000000000000078> <p:0x0000000078> ff 44 03 d5   msr daifclr, #4
Note: There are more options that the new-tracer-tool command supports, such as including the access type or register changes in the log. You can find the entire list of parameters using the simulator help.