m68k-elf: Zeroed area in ELF file

m68k-elf: Zeroed area in ELF file

[Christian Meusel]

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Hello!

I'm compiling eCos for the ColdFire MCF5282. When linking all together, 
the resulting ELF file contains a corrupted interrupt vector table. 
Excactly the first kilobyte of the ROM interrupt vector table is zeroed 
- no matter what the code from object or archive files contains.

Linking occurs with help of the attached linker script and linking is 
invoked as follows:

     m68k-elf-gcc -m528x -g -nostdlib -Wl,--gc-sections \
         -Wl,-static -L<BUILDPATH>/install/lib -Ttarget.ld \
         -o <BUILDPATH>/install/bin/redboot.elf \
         <BUILDPATH>/install/lib/version.o

The data for the vector table is provided in an archive named 
libtarget.a which is referenced by the linker script. In this archive, 
the vector table contains references to relocatable symbols.

When compiling and linking with GCC 3.4.6 I'm getting the expected 
result with correctly resolved symbols in the interrupt vector table. 
The situation changes when I'm using one of the following GCC 4 variants:

     GCC 4.0.4
     GCC 4.1.2
     GCC 4.2.4

All ELF files generated by using these versions for linking have the 
first kilobyte of the interrupt vector table zeroed. The interrupt 
vector table resides in the section ".romvec" at the lowest ROM address.


Any ideas? How to make GCC 4 not to zero the first kilobyte of ROM?


Best regards

Christian


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STARTUP(vectors.o)
ENTRY(_start)
INPUT(extras.o)
GROUP(libtarget.a libgcc.a libsupc++.a)
MEMORY
{
    sdram : ORIGIN = 0x00000000, LENGTH = 0x01000000
    devs : ORIGIN = 0x40000000, LENGTH = 0x40000000
    sram : ORIGIN = 0x20000000, LENGTH = 0x00010000
    int_flash : ORIGIN = 0xF0000000, LENGTH = 0x00040000
    ext_flash : ORIGIN = 0xFFE00000, LENGTH = 0x00200000
}
SECTIONS
{
   
    .romvec 0xF0000000 : { __romvec_start = ABSOLUTE (.); . = .; KEEP(*(.romvec)); . = ALIGN(4); __romvec_end = ABSOLUTE (.); __romvec_size = ABSOLUTE (.) - ABSOLUTE(__romvec_start); } > int_flash
    .boot ALIGN (0x4) : { . = .; *(.boot*) . = ALIGN(4); } > int_flash
    .text ALIGN (0x4) : { _stext = .; *(.text*) *(.gnu.warning) *(.gnu.linkonce*) *(.init) . = ALIGN(4); } > int_flash _etext = .; PROVIDE (etext = .);
    .fini ALIGN (0x4) : { . = .; *(.fini) . = ALIGN(4); } > int_flash
    .rodata1 ALIGN (0x4) : { . = .; *(.rodata1*) . = ALIGN(4); } > int_flash
    .rodata ALIGN (0x4) : { . = .; *(.rodata*) . = ALIGN(4); } > int_flash
    .fixup ALIGN (0x4) : { __FIXUP_START__ = ABSOLUTE(.); *(.fixup) . = ALIGN(4); __FIXUP_END__ = ABSOLUTE(.); } > int_flash
    .gcc_except_table ALIGN (0x4) : { __EXCEPT_START__ = ABSOLUTE(.); *(.gcc_except_table) . = ALIGN(4); __EXCEPT_END__ = ABSOLUTE(.); } > int_flash
    .ramvec 0x20000000 (NOLOAD) : { __ramvec_start = ABSOLUTE (.); . = .; KEEP(*(.ramvec)); . = ALIGN(4); __ramvec_end = ABSOLUTE (.); __ramvec_size = ABSOLUTE (.) - ABSOLUTE(__ramvec_start); } > sram
    .virtual_vec_table ALIGN (0x4) (NOLOAD) : { __virtual_vec_table_start = ABSOLUTE (.); . += 0x100; __virtual_vec_table_end = ABSOLUTE (.); __virtual_vec_table_size = ABSOLUTE (.) - ABSOLUTE(__virtual_vec_table_start); } > sram
    .data ALIGN (0x4) : AT ((LOADADDR (.gcc_except_table) + SIZEOF (.gcc_except_table) + 4 - 1) & ~ (4 - 1)) { __ram_data_start = ABSOLUTE(.); *(.data*) __GOT1_START__ = ABSOLUTE(.); *(.got1) __GOT1_END__ = ABSOLUTE(.); . = ALIGN (4); __CTOR_LIST__ = ABSOLUTE(.); KEEP(*(SORT(.ctors*))); __CTOR_END__ = ABSOLUTE(.); __DTOR_LIST__ = ABSOLUTE(.); KEEP(*(SORT(.dtors*))) __DTOR_END__ = ABSOLUTE(.); . = ALIGN(4); KEEP(*( SORT (.ecos.table.*))); . = ALIGN (4); *( .2ram.*) ; __GOT2_START__ = ABSOLUTE(.); *(.got2) __GOT2_END__ = ABSOLUTE(.); __GOT_START = ABSOLUTE(.); _GLOBAL_OFFSET_TABLE_ = ABSOLUTE(. + 32768); _SDA_BASE_ = ABSOLUTE(.); *(.got.plt) *(.got) __GOT_END__ = ABSOLUTE(.); *(.dynamic) *(.eh_frame) __SDATA_START__ = ABSOLUTE(.); *(.sdata) *(.sdata.*) __SDATA2_START__ = ABSOLUTE(.); *(.sdata2*) . = ALIGN(4); __ram_data_end = ABSOLUTE(.); __ram_data_size = ABSOLUTE (.) - ABSOLUTE(__ram_data_start); } > sram __rom_data_start = LOADADDR(.data); __rom_data_size = SIZEOF(.data); __rom_data_end = __rom_data_start + __rom_data_size;
    .bss ALIGN (0x4) (NOLOAD) : { __bss_start = ABSOLUTE (.); . = .; *(.dynbss*) *(.bss*) *(COMMON) *(.sbss*) *(.scommon*) . = ALIGN(4); __bss_end = ABSOLUTE (.); __bss_size = ABSOLUTE (.) - ABSOLUTE(__bss_start); } > sram
    .uninvar ALIGN (0x4) (NOLOAD) : { __uninvar_start = ABSOLUTE (.); . = .; *(.uninvar); . = ALIGN(4); __uninvar_end = ABSOLUTE (.); __uninvar_size = ABSOLUTE (.) - ABSOLUTE(__uninvar_start); } > sram
    __heap1 = ALIGN (0x4);
    __romram_copy_source = LOADADDR(.data);
    __romram_copy_dest = ADDR(.data);
    __romram_copy_length = SIZEOF(.data);
    .stab 0 (NOLOAD) : { *(.stab) } .stabstr 0 (NOLOAD) : { *(.stabstr) } .comment 0 (NOLOAD) : { *(.comment) } . = ALIGN(0x4); _end = .; PROVIDE (end = .);
}
hal_virtual_vector_table = __virtual_vec_table_start;

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