xref: /netbsd-src/external/gpl3/gdb/dist/gdb/m68k-tdep.h (revision c664bcbdbaf2e5f4396e0003178d093be0d65cd2)
1 /* Target-dependent code for the Motorola 68000 series.
2 
3    Copyright (C) 1990-2024 Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 3 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19 
20 #ifndef M68K_TDEP_H
21 #define M68K_TDEP_H
22 
23 #include "gdbarch.h"
24 
25 class frame_info_ptr;
26 
27 /* Register numbers of various important registers.  */
28 
29 enum m68k_regnum
30 {
31   M68K_D0_REGNUM = 0,
32   M68K_D1_REGNUM = 1,
33   M68K_D2_REGNUM = 2,
34   M68K_D7_REGNUM = 7,
35   M68K_A0_REGNUM = 8,
36   M68K_A1_REGNUM = 9,
37   M68K_A2_REGNUM = 10,
38   M68K_FP_REGNUM = 14,		/* Address of executing stack frame.  */
39   M68K_SP_REGNUM = 15,		/* Address of top of stack.  */
40   M68K_PS_REGNUM = 16,		/* Processor status.  */
41   M68K_PC_REGNUM = 17,		/* Program counter.  */
42   M68K_FP0_REGNUM = 18,		/* Floating point register 0.  */
43   M68K_FPC_REGNUM = 26,		/* 68881 control register.  */
44   M68K_FPS_REGNUM = 27,		/* 68881 status register.  */
45   M68K_FPI_REGNUM = 28
46 };
47 
48 /* Number of machine registers.  */
49 #define M68K_NUM_REGS	(M68K_FPI_REGNUM + 1)
50 
51 /* Size of the largest register.  */
52 #define M68K_MAX_REGISTER_SIZE	12
53 
54 /* Convention for returning structures.  */
55 
56 enum struct_return
57 {
58   pcc_struct_return,		/* Return "short" structures in memory.  */
59   reg_struct_return		/* Return "short" structures in registers.  */
60 };
61 
62 /* Particular flavour of m68k.  */
63 enum m68k_flavour
64   {
65     m68k_no_flavour,
66     m68k_coldfire_flavour,
67     m68k_fido_flavour
68   };
69 
70 /* Target-dependent structure in gdbarch.  */
71 
72 struct m68k_gdbarch_tdep : gdbarch_tdep_base
73 {
74   /* Offset to PC value in the jump buffer.  If this is negative,
75      longjmp support will be disabled.  */
76   int jb_pc = 0;
77   /* The size of each entry in the jump buffer.  */
78   size_t jb_elt_size = 0;
79 
80   /* Register in which the address to store a structure value is
81      passed to a function.  */
82   int struct_value_regnum = 0;
83 
84   /* Register in which a pointer value is returned.  In the SVR4 ABI,
85      this is %a0, but in GCC's "embedded" ABI, this is %d0.  */
86   int pointer_result_regnum = 0;
87 
88   /* Convention for returning structures.  */
89   enum struct_return struct_return {};
90 
91   /* Convention for returning floats.  zero in int regs, non-zero in float.  */
92   int float_return = 0;
93 
94   /* The particular flavour of m68k.  */
95   enum m68k_flavour flavour {};
96 
97   /* Flag set if the floating point registers are present, or assumed
98      to be present.  */
99   int fpregs_present = 0;
100 
101    /* ISA-specific data types.  */
102   struct type *m68k_ps_type = nullptr;
103   struct type *m68881_ext_type = nullptr;
104 };
105 
106 /* Initialize a SVR4 architecture variant.  */
107 extern void m68k_svr4_init_abi (struct gdbarch_info, struct gdbarch *);
108 
109 
110 /* Functions exported from m68k-bsd-tdep.c.  */
111 
112 extern int m68kbsd_fpreg_offset (struct gdbarch *gdbarch, int regnum);
113 
114 #endif /* m68k-tdep.h */
115