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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * include/asm-v850/flat.h -- uClinux flat-format executables
3 *
4 * Copyright (C) 2002,03 NEC Electronics Corporation
5 * Copyright (C) 2002,03 Miles Bader <miles@gnu.org>
6 *
7 * This file is subject to the terms and conditions of the GNU General
8 * Public License. See the file COPYING in the main directory of this
9 * archive for more details.
10 *
11 * Written by Miles Bader <miles@gnu.org>
12 */
13
14#ifndef __V850_FLAT_H__
15#define __V850_FLAT_H__
16
17/* The amount by which a relocation can exceed the program image limits
18 without being regarded as an error. On the v850, the relocations of
19 some base-pointers can be offset by 0x8000 (to allow better usage of the
20 space offered by 16-bit signed offsets -- in most cases the offsets used
21 with such a base-pointer will be negative). */
22
23#define flat_reloc_valid(reloc, size) ((reloc) <= (size + 0x8000))
24
25#define flat_stack_align(sp) /* nothing needed */
26#define flat_argvp_envp_on_stack() 0
27#define flat_old_ram_flag(flags) (flags)
28
29/* We store the type of relocation in the top 4 bits of the `relval.' */
30
31/* Convert a relocation entry into an address. */
32static inline unsigned long
33flat_get_relocate_addr (unsigned long relval)
34{
35 return relval & 0x0fffffff; /* Mask out top 4-bits */
36}
37
38#define flat_v850_get_reloc_type(relval) ((relval) >> 28)
39
40#define FLAT_V850_R_32 0 /* Normal 32-bit reloc */
41#define FLAT_V850_R_HI16S_LO15 1 /* High 16-bits + signed 15-bit low field */
42#define FLAT_V850_R_HI16S_LO16 2 /* High 16-bits + signed 16-bit low field */
43
44/* Extract the address to be relocated from the symbol reference at RP;
45 RELVAL is the raw relocation-table entry from which RP is derived.
46 For the v850, RP should always be half-word aligned. */
47static inline unsigned long flat_get_addr_from_rp (unsigned long *rp,
48 unsigned long relval,
49 unsigned long flags)
50{
51 short *srp = (short *)rp;
52
53 switch (flat_v850_get_reloc_type (relval))
54 {
55 case FLAT_V850_R_32:
56 /* Simple 32-bit address. */
57 return srp[0] | (srp[1] << 16);
58
59 case FLAT_V850_R_HI16S_LO16:
60 /* The high and low halves of the address are in the 16
61 bits at RP, and the 2nd word of the 32-bit instruction
62 following that, respectively. The low half is _signed_
63 so we have to sign-extend it and add it to the upper
64 half instead of simply or-ing them together.
65
66 Unlike most relocated address, this one is stored in
67 native (little-endian) byte-order to avoid problems with
68 trashing the low-order bit, so we have to convert to
69 network-byte-order before returning, as that's what the
70 caller expects. */
71 return htonl ((srp[0] << 16) + srp[2]);
72
73 case FLAT_V850_R_HI16S_LO15:
74 /* The high and low halves of the address are in the 16
75 bits at RP, and the upper 15 bits of the 2nd word of the
76 32-bit instruction following that, respectively. The
77 low half is _signed_ so we have to sign-extend it and
78 add it to the upper half instead of simply or-ing them
79 together. The lowest bit is always zero.
80
81 Unlike most relocated address, this one is stored in
82 native (little-endian) byte-order to avoid problems with
83 trashing the low-order bit, so we have to convert to
84 network-byte-order before returning, as that's what the
85 caller expects. */
86 return htonl ((srp[0] << 16) + (srp[2] & ~0x1));
87
88 default:
89 return ~0; /* bogus value */
90 }
91}
92
93/* Insert the address ADDR into the symbol reference at RP;
94 RELVAL is the raw relocation-table entry from which RP is derived.
95 For the v850, RP should always be half-word aligned. */
96static inline void flat_put_addr_at_rp (unsigned long *rp, unsigned long addr,
97 unsigned long relval)
98{
99 short *srp = (short *)rp;
100
101 switch (flat_v850_get_reloc_type (relval)) {
102 case FLAT_V850_R_32:
103 /* Simple 32-bit address. */
104 srp[0] = addr & 0xFFFF;
105 srp[1] = (addr >> 16);
106 break;
107
108 case FLAT_V850_R_HI16S_LO16:
109 /* The high and low halves of the address are in the 16
110 bits at RP, and the 2nd word of the 32-bit instruction
111 following that, respectively. The low half is _signed_
112 so we must carry its sign bit to the upper half before
113 writing the upper half. */
114 srp[0] = (addr >> 16) + ((addr >> 15) & 0x1);
115 srp[2] = addr & 0xFFFF;
116 break;
117
118 case FLAT_V850_R_HI16S_LO15:
119 /* The high and low halves of the address are in the 16
120 bits at RP, and the upper 15 bits of the 2nd word of the
121 32-bit instruction following that, respectively. The
122 low half is _signed_ so we must carry its sign bit to
123 the upper half before writing the upper half. The
124 lowest bit we preserve from the existing instruction. */
125 srp[0] = (addr >> 16) + ((addr >> 15) & 0x1);
126 srp[2] = (addr & 0xFFFE) | (srp[2] & 0x1);
127 break;
128 }
129}
130
131#endif /* __V850_FLAT_H__ */