Skip to content
  • H. Peter Anvin's avatar
    x86, realmode: 16-bit real-mode code support for relocs tool · 6520fe55
    H. Peter Anvin authored
    
    
    A new option is added to the relocs tool called '--realmode'.
    This option causes the generation of 16-bit segment relocations
    and 32-bit linear relocations for the real-mode code. When
    the real-mode code is moved to the low-memory during kernel
    initialization, these relocation entries can be used to
    relocate the code properly.
    
    In the assembly code 16-bit segment relocations must be relative
    to the 'real_mode_seg' absolute symbol. Linear relocations must be
    relative to a symbol prefixed with 'pa_'.
    
    16-bit segment relocation is used to load cs:ip in 16-bit code.
    Linear relocations are used in the 32-bit code for relocatable
    data references. They are declared in the linker script of the
    real-mode code.
    
    The relocs tool is moved to arch/x86/tools/relocs.c, and added new
    target archscripts that can be used to build scripts needed building
    an architecture.  be compiled before building the arch/x86 tree.
    
    [ hpa: accelerating this because it detects invalid absolute
      relocations, a serious bug in binutils 2.22.52.0.x which currently
      produces bad kernels. ]
    
    Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
    Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com
    
    
    Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@intel.com>
    Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
    Cc: <stable@vger.kernel.org>
    6520fe55