CCS/RM48L952: CCS9 debugger start location

petrinm

Part Number: RM48L952

Tool/software: Code Composer Studio

Hi,

I have a multi part embedded firmware project where the kernel and application (+ bootloader) are separate projects. The software boots so that after bootloader the kernel program starts and initializes the hardware. After that the kernel calls the application software's start function (_c_init00) that has been fixed to known location. I have got this working fine when the processor (RM48) boots itself after cold reset. When I try to flash and debug the application, the debugger flashes only the application (as planned) to internal flash memory and then starts running code directly from application's _c_init00 skipping the kernel's hardware initialization code. In the similar way if I flash/debug the kernel the debugger will skip the bootloader.

Is there way to set start/reset location where the CCS debugger starts running the code so that the kernel code would be ran when debugging the application? I wasn't able to find such parameter from the UI.

over 6 years ago

0 Chester Gillon over 6 years ago

Guru 92251 points

I think the CCS debugger gets the start location from the "Entry point address" in the ELF header of the .out file.

When using the TI tool chain the --entry_point option may be used to change the symbol for the entry point from the default symbol of _c_int00.

I tried the following in a linker command file for a RM57 project to set an arbitrary entry point:

/* Set the entry point to the kernel (arbitrary address set for this example) */
kernel_entry=0x123456;
--entry_point=kernel_entry

/* Suppress the warning since we have above deliberately overriden the entry point */
/* - 10063: Warning about entry point not being _c_int00          */
--diag_suppress=10063

/* Prevent the linker from discarding the run time library entry point. Not sure if this is necessary */
--retain=_c_int00

And the output from readelf -h reported that the entry point had been set to the requested address:

ELF Header:
  Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00 
  Class:                             ELF32
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           ARM
  Version:                           0x1
  Entry point address:               0x123456
  Start of program headers:          248392 (bytes into file)
  Start of section headers:          248488 (bytes into file)
  Flags:                             0x5000000, Version5 EABI
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         3
  Size of section headers:           40 (bytes)
  Number of section headers:         24
  Section header string table index: 23

I don't have a multi-part firmware project at the momment to check that has the expected effect on the CCS debugger.

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CCS/RM48L952: CCS9 debugger start location