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 int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
  36                                         u32 *addr, u32 *persistent)
  37 {
  38         u32 *p = (__force u32 *)rp;
  39
  40         /* Is it a split 64/32 reference? */
  41         if (relval & 0x80000000) {
  42                 /* Grab the two halves of the reference */
  43                 u32 val_hi, val_lo;
  44
  45                 val_hi = get_unaligned(p);
  46                 val_lo = get_unaligned(p+1);
  47
  48                 /* Crack the address out */
  49                 *addr = ((val_hi & 0xffff) << 16) + (val_lo & 0xffff);
  50         } else {
  51                 /* Get the address straight out */
  52                 *addr = get_unaligned(p);
  53         }
  54
  55         return 0;
  56 }
  57
  58 /*
  59  * Insert an address into the symbol reference at rp. rp is potentially
  60  * unaligned.
  61  */
  62
  63 static inline int
  64 flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 relval)
  65 {
  66         u32 *p = (__force u32 *)rp;
  67         /* Is this a split 64/32 reloc? */
  68         if (relval & 0x80000000) {
  69                 /* Get the two "halves" */
  70                 unsigned long val_hi = get_unaligned(p);
  71                 unsigned long val_lo = get_unaligned(p + 1);
  72
  73                 /* insert the address */
  74                 val_hi = (val_hi & 0xffff0000) | addr >> 16;
  75                 val_lo = (val_lo & 0xffff0000) | (addr & 0xffff);
  76
  77                 /* store the two halves back into memory */
  78                 put_unaligned(val_hi, p);
  79                 put_unaligned(val_lo, p+1);
  80         } else {
  81                 /* Put it straight in, no messing around */
  82                 put_unaligned(addr, p);
  83         }
  84         return 0;
  85 }
  86
  87 #define flat_get_relocate_addr(rel)     (rel & 0x7fffffff)
  88
  89 #endif /* _ASM_MICROBLAZE_FLAT_H */