Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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 | |
| 29 | /* We store the type of relocation in the top 4 bits of the `relval.' */ |
| 30 | |
| 31 | /* Convert a relocation entry into an address. */ |
| 32 | static inline unsigned long |
| 33 | flat_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. */ |
| 47 | static 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. */ |
| 96 | static 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__ */ |