initializing .bss to zero

John Fisher

I'm using the C55x compiler, large memory model, and --rom-model with the linker. I refer to the fact that statically allocated variables without explicit initialization, are not automatically initialized to zero. I think a few extra lines at the beginning of _auto_init in autoinit.asm would fix this by zeroing the .bss before data is copied from .cinit. I don't know C55x assembler.

Has someone else already done this, and are they willing to post the patch to autoinit.asm, preferably with a linker file with the definitions of any extra symbols that might be necessary?

over 13 years ago

George Mock over 13 years ago

TI__Guru**** 252170 points

I don't have the assembly solution you suggest. Another method is discussed in the C5500 compiler manual, in the section titled Initializing Static and Global Variables. You use the linker to zero the .bss section.

Thanks and regards,

-George

John Fisher over 13 years ago in reply to George Mock

Expert 1030 points

Georgem said:

Another method is discussed in the C5500 compiler manual, in the section titled Initializing Static and Global Variables. You use the linker to zero the .bss section.

-George

George, thanks for the reply, but that solution is unsatisfactory. It increases the image size and therefore the time taken to load by JTAG debugger.

Douglas Gwyn over 13 years ago in reply to John Fisher

Expert 2210 points

I don't know about the C5500, but for the C6xxx you can compile and link using either COFF or EABI object file format; the COFF environment doesn't deafult-zero-initialize but the EABI enviropnment does. Maybe there is some option like that for the C5500?

A patch to the start-up initialization module might not be feasible, if the linker doesn't define some external symbols marking the .bss boundaries. You could probably force it do by some surgery on the linker command file.. Good luck!

Archaeologist over 13 years ago in reply to Douglas Gwyn

TI__Guru* 84285 points

TI only supports EABI for C6000, ARM, and MSP430. I do not expect it will ever be supported for C5500.

Code Composer Studio™︎

Code Composer Studio forum

initializing .bss to zero