arch/microblaze/include/asm/flat.h

   1 /*
   2  * uClinux flat-format executables
   3  *
   4  * Copyright (C) 2005 John Williams <jwilliams@itee.uq.edu.au>
   5  *
   6  * This file is subject to the terms and conditions of the GNU General
   7  * Public License. See the file COPYING in the main directory of this
   8  * archive for more details.
   9  */
  10
  11 #ifndef _ASM_MICROBLAZE_FLAT_H
  12 #define _ASM_MICROBLAZE_FLAT_H
  13
  14 #include <asm/unaligned.h>
  15
  16 #define flat_argvp_envp_on_stack()      0
  17 #define flat_old_ram_flag(flags)        (flags)
  18 #define flat_reloc_valid(reloc, size)   ((reloc) <= (size))
  19 #define flat_set_persistent(relval, p)          0
  20
  21 /*
  22  * Microblaze works a little differently from other arches, because
  23  * of the MICROBLAZE_64 reloc type. Here, a 32 bit address is split
  24  * over two instructions, an 'imm' instruction which provides the top
  25  * 16 bits, then the instruction "proper" which provides the low 16
  26  * bits.
  27  */
  28
  29 /*
  30  * Crack open a symbol reference and extract the address to be
  31  * relocated. rp is a potentially unaligned pointer to the
  32  * reference
  33  */
  34
  35 static inline unsigned long
  36 flat_get_addr_from_rp(unsigned long *rp, unsigned long relval,
  37                         unsigned long flags, unsigned long *persistent)
  38 {
  39         unsigned long addr;
  40         (void)flags;
  41
  42         /* Is it a split 64/32 reference? */
  43         if (relval & 0x80000000) {
  44                 /* Grab the two halves of the reference */
  45                 unsigned long val_hi, val_lo;
  46
  47                 val_hi = get_unaligned(rp);
  48                 val_lo = get_unaligned(rp+1);
  49
  50                 /* Crack the address out */
  51                 addr = ((val_hi & 0xffff) << 16) + (val_lo & 0xffff);
  52         } else {
  53                 /* Get the address straight out */
  54                 addr = get_unaligned(rp);
  55         }
  56
  57         return addr;
  58 }
  59
  60 /*
  61  * Insert an address into the symbol reference at rp. rp is potentially
  62  * unaligned.
  63  */
  64
  65 static inline void
  66 flat_put_addr_at_rp(unsigned long *rp, unsigned long addr, unsigned long relval)
  67 {
  68         /* Is this a split 64/32 reloc? */
  69         if (relval & 0x80000000) {
  70                 /* Get the two "halves" */
  71                 unsigned long val_hi = get_unaligned(rp);
  72                 unsigned long val_lo = get_unaligned(rp + 1);
  73
  74                 /* insert the address */
  75                 val_hi = (val_hi & 0xffff0000) | addr >> 16;
  76                 val_lo = (val_lo & 0xffff0000) | (addr & 0xffff);
  77
  78                 /* store the two halves back into memory */
  79                 put_unaligned(val_hi, rp);
  80                 put_unaligned(val_lo, rp+1);
  81         } else {
  82                 /* Put it straight in, no messing around */
  83                 put_unaligned(addr, rp);
  84         }
  85 }
  86
  87 #define flat_get_relocate_addr(rel)     (rel & 0x7fffffff)
  88
  89 #endif /* _ASM_MICROBLAZE_FLAT_H */