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1/*
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#define flat_set_persistent(relval, p) 0
29
30/* We store the type of relocation in the top 4 bits of the `relval.' */
31
32/* Convert a relocation entry into an address. */
33static inline unsigned long
34flat_get_relocate_addr (unsigned long relval)
35{
36 return relval & 0x0fffffff; /* Mask out top 4-bits */
37}
38
39#define flat_v850_get_reloc_type(relval) ((relval) >> 28)
40
41#define FLAT_V850_R_32 0 /* Normal 32-bit reloc */
42#define FLAT_V850_R_HI16S_LO15 1 /* High 16-bits + signed 15-bit low field */
43#define FLAT_V850_R_HI16S_LO16 2 /* High 16-bits + signed 16-bit low field */
44
45/* Extract the address to be relocated from the symbol reference at RP;
46 RELVAL is the raw relocation-table entry from which RP is derived.
47 For the v850, RP should always be half-word aligned. */
48static inline unsigned long flat_get_addr_from_rp (unsigned long *rp,
49 unsigned long relval,
50 unsigned long flags,
51 unsigned long *persistent)
52{
53 short *srp = (short *)rp;
54
55 switch (flat_v850_get_reloc_type (relval))
56 {
57 case FLAT_V850_R_32:
58 /* Simple 32-bit address. */
59 return srp[0] | (srp[1] << 16);
60
61 case FLAT_V850_R_HI16S_LO16:
62 /* The high and low halves of the address are in the 16
63 bits at RP, and the 2nd word of the 32-bit instruction
64 following that, respectively. The low half is _signed_
65 so we have to sign-extend it and add it to the upper
66 half instead of simply or-ing them together.
67
68 Unlike most relocated address, this one is stored in
69 native (little-endian) byte-order to avoid problems with
70 trashing the low-order bit, so we have to convert to
71 network-byte-order before returning, as that's what the
72 caller expects. */
73 return htonl ((srp[0] << 16) + srp[2]);
74
75 case FLAT_V850_R_HI16S_LO15:
76 /* The high and low halves of the address are in the 16
77 bits at RP, and the upper 15 bits of the 2nd word of the
78 32-bit instruction following that, respectively. The
79 low half is _signed_ so we have to sign-extend it and
80 add it to the upper half instead of simply or-ing them
81 together. The lowest bit is always zero.
82
83 Unlike most relocated address, this one is stored in
84 native (little-endian) byte-order to avoid problems with
85 trashing the low-order bit, so we have to convert to
86 network-byte-order before returning, as that's what the
87 caller expects. */
88 return htonl ((srp[0] << 16) + (srp[2] & ~0x1));
89
90 default:
91 return ~0; /* bogus value */
92 }
93}
94
95/* Insert the address ADDR into the symbol reference at RP;
96 RELVAL is the raw relocation-table entry from which RP is derived.
97 For the v850, RP should always be half-word aligned. */
98static inline void flat_put_addr_at_rp (unsigned long *rp, unsigned long addr,
99 unsigned long relval)
100{
101 short *srp = (short *)rp;
102
103 switch (flat_v850_get_reloc_type (relval)) {
104 case FLAT_V850_R_32:
105 /* Simple 32-bit address. */
106 srp[0] = addr & 0xFFFF;
107 srp[1] = (addr >> 16);
108 break;
109
110 case FLAT_V850_R_HI16S_LO16:
111 /* The high and low halves of the address are in the 16
112 bits at RP, and the 2nd word of the 32-bit instruction
113 following that, respectively. The low half is _signed_
114 so we must carry its sign bit to the upper half before
115 writing the upper half. */
116 srp[0] = (addr >> 16) + ((addr >> 15) & 0x1);
117 srp[2] = addr & 0xFFFF;
118 break;
119
120 case FLAT_V850_R_HI16S_LO15:
121 /* The high and low halves of the address are in the 16
122 bits at RP, and the upper 15 bits of the 2nd word of the
123 32-bit instruction following that, respectively. The
124 low half is _signed_ so we must carry its sign bit to
125 the upper half before writing the upper half. The
126 lowest bit we preserve from the existing instruction. */
127 srp[0] = (addr >> 16) + ((addr >> 15) & 0x1);
128 srp[2] = (addr & 0xFFFE) | (srp[2] & 0x1);
129 break;
130 }
131}
132
133#endif /* __V850_FLAT_H__ */