CrossSim is a program that allows you to run CrossStudio's instruction set simulator from the command line.

The primary purpose of CrossSim is to enable command line tests to be run. The debug I/O provided by CrossStudio is supported, as are command line arguments and exit.

CrossSim will accept a single elf file, it will allocate and load memory regions based on the program sections in the elf file. CrossSim will start execution from the entry point symbol contained in the elf file. CrossSim will terminate when exit is called or execution reaches a specified symbol.


Assuming that app.c contains the following

#include <stdio.h>
#include <stdlib.h>
main(int argc, const char *argv[])
  int i;
  for (i = 1; i < argc; i++)
    printf("argv[%d]=%s\n", i, argv[i]);

and app.elf has been built with the preprocessor definition FULL_LIBRARY then

crosssim app.elf hello world 

will produce the output


if the debug I/O implementation has to set breakpoints or poll memory locations then you can supply the name of the symbol to breakpoint on that will enable the debug I/O

crosssim app.elf -startup __startup_complete hello world 

if the application uses memory that isn't allocated in the elf file then you can supply the memory segments that the simulator should create

crosssim app.elf -segments 0x08000000;0x10000;0x20000000;0x10000 

and there is an alternative form of this

crosssim app.elf -memory-segments "FLASH RX 0x08000000 0x10000;SRAM RWX 0x20000000 0x10000" 

The simulator attempts to determine the machine architecture from data in the elf file this can be override using

crosssim app.elf -arch v7m 

If the simulator doesn't support the architecture then the the list of supported architectures will be displayed.

The simulator will start executing at the entry point symbol in the elf file. If the application doesn't set the stack pointer then you can supply this

crosssim app.elf -stackpointer __stack_end__ 

If the application doesn't call exit then you can supply a symbol to breakpoint on that will terminate the simulation

crosssim app.elf -end _Exit 

You can show an instruction trace

crosssim app.elf -trace 

Which will show the addresses of instructions, the instruction opcode and the disassembly

0x000002d8 E59F003C    ldr r0, =0xE01FC000
0x000002dc E3A01000    mov r1, #0
0x000002e0 E5801000    str r1, [r0]
0x000002e4 E3A01003    mov r1, #3
0x000002e8 E5801004    str r1, [r0, #4]
0x000002ec E3A01002    mov r1, #2

You can display the instruction execution counts at the end of the simulation

crosssim app.elf -counts 

Which will show the addresses of instructions, with the number of times executed


crosssim file [options] args

Option Description
-arch 'a' Specify architecture to simulate
-arch list List supported architectures
-counts Show execution counts when the simulation ends
-end 's' Specify the symbol to end simulation
-max 'c' Specify the maximum number of instructions to simulate
-memory-segments 'name [access] start size;…' Specify the list of memory segments
-segments 'start;size;…' Specify the list of memory segments
-stackpointer 's' Specify the starting stackpoint symbol
-startup 's' Specify the startup completion point symbol
-trace Show instruction execution