huge binary files with objcopy

Question

Im having problems when I define global variables in a basic C program for an ARM9 processor. I\'m using EABI GNU compiler and the binary generated from a 12KB elf is 4GB! I

Answer 1

You are creating a file which will starts at address 0x01000000 and will contains at least up to address 0xFFFF0000. No wonder that it is nearly 4GB. What would you like? Try with options -R to remove the data segments if you don't want them (as it is probably the case if you are preparing a ROM initialization file).

Answer 2

I found the problem. The objcopy command will try to create the entire address space described in the linker script, from the lowest address to the highest including everything in between. You can tell it to just generate the ROM code as follows:

objcopy ./main.elf -j ROM --output-target=binary ./main.bin

I also changed the linker script slightly

MEMORY {
  ram(WXAIL) : ORIGIN = 0x01000000, LENGTH = 32K    
  rom(RX)    : ORIGIN = 0xFFFF0000, LENGTH = 32K                    
}

SECTIONS {
  ROM : { 
    *(vectors);
    *(.text);
    *(.rodata);
  } > rom 

  RAM : {
    *(.data); 
    *(.bss);
  } > ram 
}