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Diffstat (limited to 'include/asm-v850/flat.h')
| -rw-r--r-- | include/asm-v850/flat.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/include/asm-v850/flat.h b/include/asm-v850/flat.h new file mode 100644 index 00000000000..3888f59d688 --- /dev/null +++ b/include/asm-v850/flat.h @@ -0,0 +1,131 @@ +/* + * include/asm-v850/flat.h -- uClinux flat-format executables + * + * Copyright (C) 2002,03 NEC Electronics Corporation + * Copyright (C) 2002,03 Miles Bader <miles@gnu.org> + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of this + * archive for more details. + * + * Written by Miles Bader <miles@gnu.org> + */ + +#ifndef __V850_FLAT_H__ +#define __V850_FLAT_H__ + +/* The amount by which a relocation can exceed the program image limits + without being regarded as an error. On the v850, the relocations of + some base-pointers can be offset by 0x8000 (to allow better usage of the + space offered by 16-bit signed offsets -- in most cases the offsets used + with such a base-pointer will be negative). */ + +#define flat_reloc_valid(reloc, size) ((reloc) <= (size + 0x8000)) + +#define flat_stack_align(sp) /* nothing needed */ +#define flat_argvp_envp_on_stack() 0 +#define flat_old_ram_flag(flags) (flags) + +/* We store the type of relocation in the top 4 bits of the `relval.' */ + +/* Convert a relocation entry into an address. */ +static inline unsigned long +flat_get_relocate_addr (unsigned long relval) +{ + return relval & 0x0fffffff; /* Mask out top 4-bits */ +} + +#define flat_v850_get_reloc_type(relval) ((relval) >> 28) + +#define FLAT_V850_R_32 0 /* Normal 32-bit reloc */ +#define FLAT_V850_R_HI16S_LO15 1 /* High 16-bits + signed 15-bit low field */ +#define FLAT_V850_R_HI16S_LO16 2 /* High 16-bits + signed 16-bit low field */ + +/* Extract the address to be relocated from the symbol reference at RP; + RELVAL is the raw relocation-table entry from which RP is derived. + For the v850, RP should always be half-word aligned. */ +static inline unsigned long flat_get_addr_from_rp (unsigned long *rp, + unsigned long relval, + unsigned long flags) +{ + short *srp = (short *)rp; + + switch (flat_v850_get_reloc_type (relval)) + { + case FLAT_V850_R_32: + /* Simple 32-bit address. */ + return srp[0] | (srp[1] << 16); + + case FLAT_V850_R_HI16S_LO16: + /* The high and low halves of the address are in the 16 + bits at RP, and the 2nd word of the 32-bit instruction + following that, respectively. The low half is _signed_ + so we have to sign-extend it and add it to the upper + half instead of simply or-ing them together. + + Unlike most relocated address, this one is stored in + native (little-endian) byte-order to avoid problems with + trashing the low-order bit, so we have to convert to + network-byte-order before returning, as that's what the + caller expects. */ + return htonl ((srp[0] << 16) + srp[2]); + + case FLAT_V850_R_HI16S_LO15: + /* The high and low halves of the address are in the 16 + bits at RP, and the upper 15 bits of the 2nd word of the + 32-bit instruction following that, respectively. The + low half is _signed_ so we have to sign-extend it and + add it to the upper half instead of simply or-ing them + together. The lowest bit is always zero. + + Unlike most relocated address, this one is stored in + native (little-endian) byte-order to avoid problems with + trashing the low-order bit, so we have to convert to + network-byte-order before returning, as that's what the + caller expects. */ + return htonl ((srp[0] << 16) + (srp[2] & ~0x1)); + + default: + return ~0; /* bogus value */ + } +} + +/* Insert the address ADDR into the symbol reference at RP; + RELVAL is the raw relocation-table entry from which RP is derived. + For the v850, RP should always be half-word aligned. */ +static inline void flat_put_addr_at_rp (unsigned long *rp, unsigned long addr, + unsigned long relval) +{ + short *srp = (short *)rp; + + switch (flat_v850_get_reloc_type (relval)) { + case FLAT_V850_R_32: + /* Simple 32-bit address. */ + srp[0] = addr & 0xFFFF; + srp[1] = (addr >> 16); + break; + + case FLAT_V850_R_HI16S_LO16: + /* The high and low halves of the address are in the 16 + bits at RP, and the 2nd word of the 32-bit instruction + following that, respectively. The low half is _signed_ + so we must carry its sign bit to the upper half before + writing the upper half. */ + srp[0] = (addr >> 16) + ((addr >> 15) & 0x1); + srp[2] = addr & 0xFFFF; + break; + + case FLAT_V850_R_HI16S_LO15: + /* The high and low halves of the address are in the 16 + bits at RP, and the upper 15 bits of the 2nd word of the + 32-bit instruction following that, respectively. The + low half is _signed_ so we must carry its sign bit to + the upper half before writing the upper half. The + lowest bit we preserve from the existing instruction. */ + srp[0] = (addr >> 16) + ((addr >> 15) & 0x1); + srp[2] = (addr & 0xFFFE) | (srp[2] & 0x1); + break; + } +} + +#endif /* __V850_FLAT_H__ */ |