Add Xtensa port

1 files changed, 230 insertions, 0 deletions

diff --git a/include/xtensa-isa.h b/include/xtensa-isa.h
new file mode 100644
index 0000000..54f750c
--- /dev/null
+++ b/include/xtensa-isa.h
@@ -0,0 +1,230 @@
+/* Interface definition for configurable Xtensa ISA support.
+   Copyright 2003 Free Software Foundation, Inc.
+
+   This file is part of BFD, the Binary File Descriptor library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#ifndef XTENSA_LIBISA_H
+#define XTENSA_LIBISA_H
+
+/* Use the statically-linked version for the GNU tools.  */
+#define STATIC_LIBISA 1
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef uint32
+#define uint32 unsigned int
+#endif
+
+/* This file defines the interface to the Xtensa ISA library.  This library
+   contains most of the ISA-specific information for a particular Xtensa
+   processor.  For example, the set of valid instructions, their opcode
+   encodings and operand fields are all included here.  To support Xtensa's
+   configurability and user-defined instruction extensions (i.e., TIE), the
+   library is initialized by loading one or more dynamic libraries; only a
+   small set of interface code is present in the statically-linked portion
+   of the library.
+
+   This interface basically defines four abstract data types.
+
+   . an instruction buffer - for holding the raw instruction bits
+   . ISA info - information about the ISA as a whole
+   . opcode info - information about individual instructions
+   . operand info - information about specific instruction operands
+
+   It would be nice to implement these as classes in C++, but the library is
+   implemented in C to match the expectations of the GNU tools.
+   Instead, the interface defines a set of functions to access each data
+   type.  With the exception of the instruction buffer, the internal
+   representations of the data structures are hidden.  All accesses must be
+   made through the functions defined here.  */
+
+typedef void* xtensa_isa;
+typedef void* xtensa_operand;
+
+
+/* Opcodes are represented here using sequential integers beginning with 0.
+   The specific value used for a particular opcode is only fixed for a
+   particular instantiation of an xtensa_isa structure, so these values
+   should only be used internally.  */
+typedef int xtensa_opcode;
+
+/* Define a unique value for undefined opcodes ("static const int" doesn't
+   seem to work for this because EGCS 1.0.3 on i686-Linux without -O won't
+   allow it to be used as an initializer).  */
+#define XTENSA_UNDEFINED -1
+
+
+typedef int libisa_module_specifier;
+
+extern xtensa_isa xtensa_isa_init (void);
+
+
+/* Instruction buffers.  */
+
+typedef uint32 xtensa_insnbuf_word;
+typedef xtensa_insnbuf_word *xtensa_insnbuf;
+
+/* Get the size in words of the xtensa_insnbuf array.  */
+extern int xtensa_insnbuf_size (xtensa_isa); 
+
+/* Allocate (with malloc) an xtensa_insnbuf of the right size.  */
+extern xtensa_insnbuf xtensa_insnbuf_alloc (xtensa_isa);
+
+/* Release (with free) an xtensa_insnbuf of the right size.  */
+extern void xtensa_insnbuf_free (xtensa_insnbuf);
+
+/* Inward and outward conversion from memory images (byte streams) to our
+   internal instruction representation.  */
+extern void xtensa_insnbuf_to_chars (xtensa_isa, const xtensa_insnbuf,
+				     char *);
+
+extern void xtensa_insnbuf_from_chars (xtensa_isa, xtensa_insnbuf,
+				       const char *);
+
+
+/* ISA information.  */
+
+/* Load the ISA information from a shared library.  If successful, this returns
+   a value which identifies the ISA for use in subsequent calls to the ISA
+   library; otherwise, it returns NULL.  Multiple ISAs can be loaded to support
+   heterogeneous multiprocessor systems.  */
+extern xtensa_isa xtensa_load_isa (libisa_module_specifier);
+
+/* Extend an existing set of ISA information by loading an additional shared
+   library of ISA information.  This is primarily intended for loading TIE
+   extensions.  If successful, the return value is non-zero.  */
+extern int xtensa_extend_isa (xtensa_isa, libisa_module_specifier);
+
+/* The default ISA.  This variable is set automatically to the ISA most
+   recently loaded and is provided as a convenience.  An exception is the GNU
+   opcodes library, where there is a fixed interface that does not allow
+   passing the ISA as a parameter and the ISA must be taken from this global
+   variable.  (Note: Since this variable is just a convenience, it is not
+   exported when libisa is built as a DLL, due to the hassle of dealing with
+   declspecs.)  */
+extern xtensa_isa xtensa_default_isa;
+
+
+/* Deallocate an xtensa_isa structure.  */
+extern void xtensa_isa_free (xtensa_isa);
+
+/* Get the maximum instruction size in bytes.  */
+extern int xtensa_insn_maxlength (xtensa_isa); 
+
+/* Get the total number of opcodes for this processor.  */
+extern int xtensa_num_opcodes (xtensa_isa);
+
+/* Translate a mnemonic name to an opcode.  Returns XTENSA_UNDEFINED if
+   the name is not a valid opcode mnemonic.  */
+extern xtensa_opcode xtensa_opcode_lookup (xtensa_isa, const char *);
+
+/* Decode a binary instruction buffer.  Returns the opcode or
+   XTENSA_UNDEFINED if the instruction is illegal.  */
+extern xtensa_opcode xtensa_decode_insn (xtensa_isa, const xtensa_insnbuf);
+
+
+/* Opcode information.  */
+
+/* Set the opcode field(s) in a binary instruction buffer.  The operand
+   fields are set to zero.  */
+extern void xtensa_encode_insn (xtensa_isa, xtensa_opcode, xtensa_insnbuf);
+
+/* Get the mnemonic name for an opcode.  */
+extern const char * xtensa_opcode_name (xtensa_isa, xtensa_opcode);
+
+/* Find the length (in bytes) of an instruction.  */
+extern int xtensa_insn_length (xtensa_isa, xtensa_opcode);
+
+/* Find the length of an instruction by looking only at the first byte.  */
+extern int xtensa_insn_length_from_first_byte (xtensa_isa, char);
+
+/* Find the number of operands for an instruction.  */
+extern int xtensa_num_operands (xtensa_isa, xtensa_opcode);
+
+/* Get the information about operand number "opnd" of a particular opcode.  */
+extern xtensa_operand xtensa_get_operand (xtensa_isa, xtensa_opcode, int);
+
+/* Operand information.  */
+
+/* Find the kind of operand.  There are three possibilities:
+   1) PC-relative immediates (e.g., "l", "L").  These can be identified with
+      the xtensa_operand_isPCRelative function.
+   2) non-PC-relative immediates ("i").
+   3) register-file short names (e.g., "a", "b", "m" and others defined
+      via TIE).  */
+extern char * xtensa_operand_kind (xtensa_operand);
+
+/* Check if an operand is an input ('<'), output ('>'), or inout ('=')
+   operand.  Note: The output operand of a conditional assignment
+   (e.g., movnez) appears here as an inout ('=') even if it is declared
+   in the TIE code as an output ('>'); this allows the compiler to
+   properly handle register allocation for conditional assignments.  */
+extern char xtensa_operand_inout (xtensa_operand);
+
+/* Get and set the raw (encoded) value of the field for the specified
+   operand.  The "set" function does not check if the value fits in the
+   field; that is done by the "encode" function below.  */
+extern uint32 xtensa_operand_get_field (xtensa_operand, const xtensa_insnbuf);
+
+extern void xtensa_operand_set_field (xtensa_operand, xtensa_insnbuf, uint32);
+
+
+/* Encode and decode operands.  The raw bits in the operand field
+   may be encoded in a variety of different ways.  These functions hide the
+   details of that encoding.  The encode function has a special return type
+   (xtensa_encode_result) to indicate success or the reason for failure; the
+   encoded value is returned through the argument pointer.  The decode function
+   has no possibility of failure and returns the decoded value.  */
+
+typedef enum
+{
+  xtensa_encode_result_ok,
+  xtensa_encode_result_align,
+  xtensa_encode_result_not_in_table,
+  xtensa_encode_result_too_low,
+  xtensa_encode_result_too_high,
+  xtensa_encode_result_not_ok,
+  xtensa_encode_result_max = xtensa_encode_result_not_ok
+} xtensa_encode_result;
+
+extern xtensa_encode_result xtensa_operand_encode (xtensa_operand, uint32 *);
+
+extern uint32 xtensa_operand_decode (xtensa_operand, uint32);
+
+
+/* For PC-relative offset operands, the interpretation of the offset may vary
+   between opcodes, e.g., is it relative to the current PC or that of the next
+   instruction?  The following functions are defined to perform PC-relative
+   relocations and to undo them (as in the disassembler).  The first function
+   takes the desired address and the PC of the current instruction and returns
+   the unencoded value to be stored in the offset field.  The second function
+   takes the unencoded offset value and the current PC and returns the address.
+   Note that these functions do not replace the encode/decode functions; the
+   operands must be encoded/decoded separately.  */
+
+extern int xtensa_operand_isPCRelative (xtensa_operand);
+
+extern uint32 xtensa_operand_do_reloc (xtensa_operand, uint32, uint32);
+
+extern uint32 xtensa_operand_undo_reloc	(xtensa_operand, uint32, uint32);
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* XTENSA_LIBISA_H */