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 /*
17 * Microblaze works a little differently from other arches, because
18 * of the MICROBLAZE_64 reloc type. Here, a 32 bit address is split
19 * over two instructions, an 'imm' instruction which provides the top
20 * 16 bits, then the instruction "proper" which provides the low 16
21 * bits.
22 */
23
24 /*
25 * Crack open a symbol reference and extract the address to be
26 * relocated. rp is a potentially unaligned pointer to the
27 * reference
28 */
29
30 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
31 u32 *addr)
32 {
33 u32 *p = (__force u32 *)rp;
34
35 /* Is it a split 64/32 reference? */
36 if (relval & 0x80000000) {
37 /* Grab the two halves of the reference */
38 u32 val_hi, val_lo;
39
40 val_hi = get_unaligned(p);
41 val_lo = get_unaligned(p+1);
42
43 /* Crack the address out */
44 *addr = ((val_hi & 0xffff) << 16) + (val_lo & 0xffff);
45 } else {
46 /* Get the address straight out */
47 *addr = get_unaligned(p);
48 }
49
50 return 0;
51 }
52
53 /*
54 * Insert an address into the symbol reference at rp. rp is potentially
55 * unaligned.
56 */
57
58 static inline int
59 flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 relval)
60 {
61 u32 *p = (__force u32 *)rp;
62 /* Is this a split 64/32 reloc? */
63 if (relval & 0x80000000) {
64 /* Get the two "halves" */
65 unsigned long val_hi = get_unaligned(p);
66 unsigned long val_lo = get_unaligned(p + 1);
67
68 /* insert the address */
69 val_hi = (val_hi & 0xffff0000) | addr >> 16;
70 val_lo = (val_lo & 0xffff0000) | (addr & 0xffff);
71
72 /* store the two halves back into memory */
73 put_unaligned(val_hi, p);
74 put_unaligned(val_lo, p+1);
75 } else {
76 /* Put it straight in, no messing around */
77 put_unaligned(addr, p);
78 }
79 return 0;
80 }
81
82 #define flat_get_relocate_addr(rel) (rel & 0x7fffffff)
83
84 #endif /* _ASM_MICROBLAZE_FLAT_H */