linux/include/asm-v850/flat.h

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/*
* 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__ */