/* memory layout */
MEMORY
{
  REMAP (rx)   : ORIGIN = 0x00000000, LENGTH = 0x00000040
  ROM (rx)     : ORIGIN = 0x00000000, LENGTH = 128K - 8K
  CONFIG (rx)     : ORIGIN = 128K - 8K, LENGTH = 8K
  RAM (rw)     : ORIGIN = 0x40000000, LENGTH = 16K
}

SECTIONS
{
.............
  .config :
  {
    KEEP(*(.config))
  } > CONFIG
...........

/* Stabs debugging sections.  */
  .stab          0 : { *(.stab) }
  .stabstr       0 : { *(.stabstr) }
  .stab.excl     0 : { *(.stab.excl) }
  .stab.exclstr  0 : { *(.stab.exclstr) }
  .stab.index    0 : { *(.stab.index) }
  .stab.indexstr 0 : { *(.stab.indexstr) }
  .comment       0 : { *(.comment) }
  /* DWARF debug sections.
     Symbols in the DWARF debugging sections are relative to the beginning
     of the section so we begin them at 0.  */
  /* DWARF 1 */
  .debug           0 : { *(.debug) }
  .line            0 : { *(.line) }
  /* GNU DWARF 1 extensions */
  .debug_srcinfo   0 : { *(.debug_srcinfo) }
  .debug_sfnames   0 : { *(.debug_sfnames) }
  /* DWARF 1.1 and DWARF 2 */
  .debug_aranges   0 : { *(.debug_aranges) }
  .debug_pubnames  0 : { *(.debug_pubnames) }
  /* DWARF 2 */
  .debug_info      0 : { *(.debug_info .gnu.linkonce.wi.*) }
  .debug_abbrev    0 : { *(.debug_abbrev) }
  .debug_line      0 : { *(.debug_line) }
  .debug_frame     0 : { *(.debug_frame) }
  .debug_str       0 : { *(.debug_str) }
  .debug_loc       0 : { *(.debug_loc) }
  .debug_macinfo   0 : { *(.debug_macinfo) }
  /* SGI/MIPS DWARF 2 extensions */
  .debug_weaknames 0 : { *(.debug_weaknames) }
  .debug_funcnames 0 : { *(.debug_funcnames) }
  .debug_typenames 0 : { *(.debug_typenames) }
  .debug_varnames  0 : { *(.debug_varnames) }

gcc -g main .o main.c
gcc -g3 main .o main.c
gcc -ggdb main .o main.c
gcc -gdwarf-2 main .o main.c