/* =============================================================================
* ud_decode() - Instruction decoder. Returns the number of bytes decoded.
* =============================================================================
*/
unsigned int ud_decode( struct ud* u )
{
inp_start(u);
if ( clear_insn( u ) ) {
; /* error */
} else if ( get_prefixes( u ) != 0 ) {
; /* error */
} else if ( search_itab( u ) != 0 ) {
; /* error */
} else if ( do_mode( u ) != 0 ) {
; /* error */
} else if ( disasm_operands( u ) != 0 ) {
; /* error */
} else if ( resolve_mnemonic( u ) != 0 ) {
; /* error */
}
/* Handle decode error. */
if ( u->error ) {
/* clear out the decode data. */
clear_insn( u );
/* mark the sequence of bytes as invalid. */
u->itab_entry = & ie_invalid;
u->mnemonic = u->itab_entry->mnemonic;
}
u->insn_offset = u->pc; /* set offset of instruction */
u->insn_fill = 0; /* set translation buffer index to 0 */
u->pc += u->inp_ctr; /* move program counter by bytes decoded */
gen_hex( u ); /* generate hex code */
/* return number of bytes disassembled. */
return u->inp_ctr;
}
static __inline int
decode_insn(struct ud *u, uint16_t ptr)
{
assert((ptr & 0x8000) == 0);
u->itab_entry = &ud_itab[ ptr ];
u->mnemonic = u->itab_entry->mnemonic;
return (resolve_mode(u) == 0 &&
decode_operands(u) == 0 &&
resolve_mnemonic(u) == 0) ? 0 : -1;
}