Linker warning after RAM section creation

frgop — Fri, 10 May 2013 06:56:08 GMT

Requirement: to create a RAM section and place it a specific memory location, for MPC5606B (very simple!)

Tools used: CW, LCF file, TRK-MPC5606B evaluation board

Sample code:

#pragma push

#pragma section sdata_type ".myRamData" ".myRamData"

extern unsigned char myU8Data; /*prototype */

unsigned char myU8Data; /*definition*/

#pragma pop

LCF:

MEMORY

{

boot_flash: org = 0x00000000, len = 0x00010000

interrupts_flash: org = 0x00010000, len = 0x00010000

internal_flash: org = 0x00020000, len = 0x00060000

add_data_flash: org = 0x00080000, len = 0x00000100

add_code_flash: org = 0x00080100, len = 0x00000100

internal_ram: org = 0x40000000, len = 0x00007B00

add_data_ram: org = 0x40007B00, len = 0x00000100

stack_ram: org = 0x40007C00, len = 0x0400

}

SECTIONS

{

...

.myRamData (DATA) : {} > add_data_ram

...

}

Result: The result is good as I am able to see the section created in MAP file (see below)

.myRamData section layout

Starting Virtual File

address Size address offset

---------------------------------

00000000 000001 40007b00 00000358 1 .myRamData main.o

00000000 000001 40007b00 00000358 1 myU8Data main.o

Problem faced:

However a Linker warning is issued as follows:

Overlap of the ROM image address of .myRamData section with executable address of .text_vle section.

Project: LINFlex_LIN_Example.mcp, Target: LINFlex_LIN-flash

How to remove this warning.

P.S: If you already guessed it, then yes you are correct, I am using the example workspace for LIN that comes along with the EVB.

Thanks in advance.

Regards,

Gopal.

Re: Linker warning after RAM section creation

frgop — Fri, 10 May 2013 08:06:25 GMT

Hello All,

The warning was removed by using LOAD directive in the LCF as follows:

.myRamData (DATA) LOAD(0x40007B00) : {} > add_data_ram

Reason:

LOAD (...) prevents relocation by ROM copy during startup; I observed that if the LOAD is not present then in the "Memory map:", under column "ROM Address" for section ".myRamData" is set to some ROM address which is used for some other code area.

Gopal.

topic Re: Linker warning after RAM section creation in CodeWarrior for MCU

Linker warning after RAM section creation

Re: Linker warning after RAM section creation