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e140f1da JG |
1 | /* Target machine description for generic Motorola 88000, for GDB. |
2 | Copyright 1986, 1987, 1988, 1989, 1990, 1991 Free Software Foundation, Inc. | |
dd3b648e RP |
3 | |
4 | This file is part of GDB. | |
5 | ||
99a7de40 | 6 | This program is free software; you can redistribute it and/or modify |
dd3b648e | 7 | it under the terms of the GNU General Public License as published by |
99a7de40 JG |
8 | the Free Software Foundation; either version 2 of the License, or |
9 | (at your option) any later version. | |
dd3b648e | 10 | |
99a7de40 | 11 | This program is distributed in the hope that it will be useful, |
dd3b648e RP |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
99a7de40 JG |
17 | along with this program; if not, write to the Free Software |
18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
dd3b648e | 19 | |
dd3b648e RP |
20 | /* g++ support is not yet included. */ |
21 | ||
dd3b648e RP |
22 | #define TARGET_BYTE_ORDER BIG_ENDIAN |
23 | ||
e140f1da JG |
24 | /* We cache information about saved registers in the frame structure, |
25 | to save us from having to re-scan function prologues every time | |
26 | a register in a non-current frame is accessed. */ | |
dd3b648e | 27 | |
e140f1da JG |
28 | #define EXTRA_FRAME_INFO \ |
29 | struct frame_saved_regs *fsr; \ | |
30 | CORE_ADDR locals_pointer; \ | |
31 | CORE_ADDR args_pointer; | |
32 | ||
33 | /* Zero the frame_saved_regs pointer when the frame is initialized, | |
34 | so that FRAME_FIND_SAVED_REGS () will know to allocate and | |
35 | initialize a frame_saved_regs struct the first time it is called. | |
36 | Set the arg_pointer to -1, which is not valid; 0 and other values | |
37 | indicate real, cached values. */ | |
dd3b648e | 38 | |
e140f1da JG |
39 | #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \ |
40 | init_extra_frame_info (fromleaf, fi) | |
41 | extern void init_extra_frame_info (); | |
dd3b648e | 42 | |
e140f1da | 43 | #define IEEE_FLOAT |
dd3b648e RP |
44 | |
45 | /* Define this if the C compiler puts an underscore at the front | |
46 | of external names before giving them to the linker. */ | |
47 | ||
48 | #define NAMES_HAVE_UNDERSCORE | |
49 | ||
dd3b648e RP |
50 | /* Offset from address of function to start of its code. |
51 | Zero on most machines. */ | |
52 | ||
53 | #define FUNCTION_START_OFFSET 0 | |
54 | ||
55 | /* Advance PC across any function entry prologue instructions | |
56 | to reach some "real" code. */ | |
57 | ||
e140f1da JG |
58 | #define SKIP_PROLOGUE(frompc) \ |
59 | skip_prologue (frompc) | |
60 | extern CORE_ADDR skip_prologue (); | |
dd3b648e RP |
61 | |
62 | /* The m88k kernel aligns all instructions on 4-byte boundaries. The | |
63 | kernel also uses the least significant two bits for its own hocus | |
64 | pocus. When gdb receives an address from the kernel, it needs to | |
65 | preserve those right-most two bits, but gdb also needs to be careful | |
66 | to realize that those two bits are not really a part of the address | |
67 | of an instruction. Shrug. */ | |
68 | ||
69 | #define ADDR_BITS_REMOVE(addr) ((addr) & ~3) | |
70 | #define ADDR_BITS_SET(addr) (((addr) | 0x00000002) - 4) | |
71 | ||
72 | /* Immediately after a function call, return the saved pc. | |
73 | Can't always go through the frames for this because on some machines | |
74 | the new frame is not set up until the new function executes | |
75 | some instructions. */ | |
76 | ||
77 | #define SAVED_PC_AFTER_CALL(frame) \ | |
e140f1da | 78 | (ADDR_BITS_REMOVE (read_register (SRP_REGNUM))) |
dd3b648e RP |
79 | |
80 | /* Stack grows downward. */ | |
81 | ||
82 | #define INNER_THAN < | |
83 | ||
84 | /* Sequence of bytes for breakpoint instruction. */ | |
85 | ||
86 | /* instruction 0xF000D1FF is 'tb0 0,r0,511' | |
87 | If Bit bit 0 of r0 is clear (always true), | |
88 | initiate exception processing (trap). | |
89 | */ | |
90 | #define BREAKPOINT {0xF0, 0x00, 0xD1, 0xFF} | |
91 | ||
92 | /* Amount PC must be decremented by after a breakpoint. | |
93 | This is often the number of bytes in BREAKPOINT | |
94 | but not always. */ | |
95 | ||
96 | #define DECR_PC_AFTER_BREAK 0 | |
97 | ||
98 | /* Nonzero if instruction at PC is a return instruction. */ | |
99 | /* 'jmp r1' or 'jmp.n r1' is used to return from a subroutine. */ | |
100 | ||
101 | #define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 2) == 0xF800) | |
102 | ||
103 | /* Return 1 if P points to an invalid floating point value. | |
e140f1da | 104 | LEN is the length in bytes. */ |
dd3b648e RP |
105 | |
106 | #define INVALID_FLOAT(p, len) IEEE_isNAN(p,len) | |
107 | ||
108 | /* Say how long (ordinary) registers are. */ | |
109 | ||
110 | #define REGISTER_TYPE long | |
111 | ||
112 | /* Number of machine registers */ | |
113 | ||
114 | #define NUM_REGS 38 | |
115 | ||
116 | /* Initializer for an array of names of registers. | |
117 | There should be NUM_REGS strings in this initializer. */ | |
118 | ||
119 | #define REGISTER_NAMES {\ | |
120 | "r0",\ | |
121 | "r1",\ | |
122 | "r2",\ | |
123 | "r3",\ | |
124 | "r4",\ | |
125 | "r5",\ | |
126 | "r6",\ | |
127 | "r7",\ | |
128 | "r8",\ | |
129 | "r9",\ | |
130 | "r10",\ | |
131 | "r11",\ | |
132 | "r12",\ | |
133 | "r13",\ | |
134 | "r14",\ | |
135 | "r15",\ | |
136 | "r16",\ | |
137 | "r17",\ | |
138 | "r18",\ | |
139 | "r19",\ | |
140 | "r20",\ | |
141 | "r21",\ | |
142 | "r22",\ | |
143 | "r23",\ | |
144 | "r24",\ | |
145 | "r25",\ | |
146 | "r26",\ | |
147 | "r27",\ | |
148 | "r28",\ | |
149 | "r29",\ | |
150 | "r30",\ | |
151 | "r31",\ | |
152 | "psr",\ | |
153 | "fpsr",\ | |
154 | "fpcr",\ | |
155 | "sxip",\ | |
156 | "snip",\ | |
157 | "sfip",\ | |
158 | "vbr",\ | |
159 | "dmt0",\ | |
160 | "dmd0",\ | |
161 | "dma0",\ | |
162 | "dmt1",\ | |
163 | "dmd1",\ | |
164 | "dma1",\ | |
165 | "dmt2",\ | |
166 | "dmd2",\ | |
167 | "dma2",\ | |
168 | "sr0",\ | |
169 | "sr1",\ | |
170 | "sr2",\ | |
171 | "sr3",\ | |
172 | "fpecr",\ | |
173 | "fphs1",\ | |
174 | "fpls1",\ | |
175 | "fphs2",\ | |
176 | "fpls2",\ | |
177 | "fppt",\ | |
178 | "fprh",\ | |
179 | "fprl",\ | |
180 | "fpit",\ | |
181 | "fpsr",\ | |
182 | "fpcr",\ | |
183 | }; | |
184 | ||
185 | ||
186 | /* Register numbers of various important registers. | |
187 | Note that some of these values are "real" register numbers, | |
188 | and correspond to the general registers of the machine, | |
189 | and some are "phony" register numbers which are too large | |
190 | to be actual register numbers as far as the user is concerned | |
191 | but do serve to get the desired values when passed to read_register. */ | |
192 | ||
193 | #define SRP_REGNUM 1 /* Contains subroutine return pointer */ | |
194 | #define RV_REGNUM 2 /* Contains simple return values */ | |
195 | #define SRA_REGNUM 12 /* Contains address of struct return values */ | |
e140f1da | 196 | #define FP_REGNUM 31 /* Reg fetched to locate frame when pgm stops */ |
dd3b648e RP |
197 | #define SP_REGNUM 31 /* Contains address of top of stack */ |
198 | #define SXIP_REGNUM 35 /* Contains Shadow Execute Instruction Pointer */ | |
199 | #define SNIP_REGNUM 36 /* Contains Shadow Next Instruction Pointer */ | |
200 | #define PC_REGNUM SXIP_REGNUM /* Program Counter */ | |
201 | #define NPC_REGNUM SNIP_REGNUM /* Next Program Counter */ | |
202 | #define PSR_REGNUM 32 /* Processor Status Register */ | |
203 | #define FPSR_REGNUM 33 /* Floating Point Status Register */ | |
204 | #define FPCR_REGNUM 34 /* Floating Point Control Register */ | |
205 | #define SFIP_REGNUM 37 /* Contains Shadow Fetched Intruction pointer */ | |
206 | #define NNPC_REGNUM SFIP_REGNUM /* Next Next Program Counter */ | |
207 | ||
208 | /* PSR status bit definitions. */ | |
209 | ||
210 | #define PSR_MODE 0x80000000 | |
211 | #define PSR_BYTE_ORDER 0x40000000 | |
212 | #define PSR_SERIAL_MODE 0x20000000 | |
213 | #define PSR_CARRY 0x10000000 | |
214 | #define PSR_SFU_DISABLE 0x000003f0 | |
215 | #define PSR_SFU1_DISABLE 0x00000008 | |
216 | #define PSR_MXM 0x00000004 | |
217 | #define PSR_IND 0x00000002 | |
218 | #define PSR_SFRZ 0x00000001 | |
219 | ||
220 | /* BCS requires that the SXIP_REGNUM (or PC_REGNUM) contain the address | |
221 | of the next instr to be executed when a breakpoint occurs. Because | |
222 | the kernel gets the next instr (SNIP_REGNUM), the instr in SNIP needs | |
223 | to be put back into SFIP, and the instr in SXIP should be shifted | |
224 | to SNIP */ | |
225 | ||
226 | /* Are you sitting down? It turns out that the 88K BCS (binary compatibility | |
227 | standard) folks originally felt that the debugger should be responsible | |
228 | for backing up the IPs, not the kernel (as is usually done). Well, they | |
229 | have reversed their decision, and in future releases our kernel will be | |
230 | handling the backing up of the IPs. So, eventually, we won't need to | |
231 | do the SHIFT_INST_REGS stuff. But, for now, since there are 88K systems out | |
232 | there that do need the debugger to do the IP shifting, and since there | |
233 | will be systems where the kernel does the shifting, the code is a little | |
234 | more complex than perhaps it needs to be (we still go inside SHIFT_INST_REGS, | |
235 | and if the shifting hasn't occurred then gdb goes ahead and shifts). */ | |
236 | ||
237 | #define SHIFT_INST_REGS | |
238 | ||
239 | /* Total amount of space needed to store our copies of the machine's | |
240 | register state, the array `registers'. */ | |
241 | ||
242 | #define REGISTER_BYTES (NUM_REGS * sizeof(REGISTER_TYPE)) | |
243 | ||
244 | /* Index within `registers' of the first byte of the space for | |
245 | register N. */ | |
246 | ||
247 | #define REGISTER_BYTE(N) ((N)*sizeof(REGISTER_TYPE)) | |
248 | ||
249 | /* Number of bytes of storage in the actual machine representation | |
250 | for register N. */ | |
251 | ||
252 | #define REGISTER_RAW_SIZE(N) (sizeof(REGISTER_TYPE)) | |
253 | ||
254 | /* Number of bytes of storage in the program's representation | |
255 | for register N. */ | |
256 | ||
257 | #define REGISTER_VIRTUAL_SIZE(N) (sizeof(REGISTER_TYPE)) | |
258 | ||
259 | /* Largest value REGISTER_RAW_SIZE can have. */ | |
260 | ||
261 | #define MAX_REGISTER_RAW_SIZE (sizeof(REGISTER_TYPE)) | |
262 | ||
263 | /* Largest value REGISTER_VIRTUAL_SIZE can have. | |
264 | /* Are FPS1, FPS2, FPR "virtual" regisers? */ | |
265 | ||
266 | #define MAX_REGISTER_VIRTUAL_SIZE (sizeof(REGISTER_TYPE)) | |
267 | ||
268 | /* Nonzero if register N requires conversion | |
269 | from raw format to virtual format. */ | |
270 | ||
271 | #define REGISTER_CONVERTIBLE(N) (0) | |
272 | ||
273 | /* Convert data from raw format for register REGNUM | |
274 | to virtual format for register REGNUM. */ | |
275 | ||
276 | #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) {bcopy ((FROM), (TO), (sizeof(REGISTER_TYPE)));} | |
277 | ||
278 | /* Convert data from virtual format for register REGNUM | |
279 | to raw format for register REGNUM. */ | |
280 | ||
281 | #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) {bcopy ((FROM), (TO), (sizeof(REGISTER_TYPE)));} | |
282 | ||
283 | /* Return the GDB type object for the "standard" data type | |
284 | of data in register N. */ | |
285 | ||
286 | #define REGISTER_VIRTUAL_TYPE(N) (builtin_type_int) | |
287 | ||
288 | /* The 88k call/return conventions call for "small" values to be returned | |
289 | into consecutive registers starting from r2. */ | |
290 | ||
291 | #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \ | |
8aa13b87 | 292 | bcopy (&(((char *)REGBUF)[REGISTER_BYTE(RV_REGNUM)]), (VALBUF), TYPE_LENGTH (TYPE)) |
dd3b648e RP |
293 | |
294 | #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF)) | |
295 | ||
296 | /* Write into appropriate registers a function return value | |
297 | of type TYPE, given in virtual format. */ | |
298 | ||
299 | #define STORE_RETURN_VALUE(TYPE,VALBUF) \ | |
300 | write_register_bytes (2*sizeof(void*), (VALBUF), TYPE_LENGTH (TYPE)) | |
301 | ||
302 | /* In COFF, if PCC says a parameter is a short or a char, do not | |
303 | change it to int (it seems the convention is to change it). */ | |
304 | ||
305 | #define BELIEVE_PCC_PROMOTION 1 | |
306 | ||
307 | /* Describe the pointer in each stack frame to the previous stack frame | |
308 | (its caller). */ | |
309 | ||
310 | /* FRAME_CHAIN takes a frame's nominal address | |
311 | and produces the frame's chain-pointer. | |
312 | ||
dd3b648e | 313 | However, if FRAME_CHAIN_VALID returns zero, |
e140f1da | 314 | it means the given frame is the outermost one and has no caller. */ |
dd3b648e | 315 | |
e140f1da JG |
316 | extern CORE_ADDR frame_chain (); |
317 | extern int frame_chain_valid (); | |
318 | extern int frameless_function_invocation (); | |
dd3b648e | 319 | |
e140f1da JG |
320 | #define FRAME_CHAIN(thisframe) \ |
321 | frame_chain (thisframe) | |
dd3b648e | 322 | |
e140f1da JG |
323 | #define FRAME_CHAIN_VALID(chain, thisframe) \ |
324 | frame_chain_valid (chain, thisframe) | |
dd3b648e | 325 | |
e140f1da JG |
326 | #define FRAMELESS_FUNCTION_INVOCATION(frame, fromleaf) \ |
327 | fromleaf = frameless_function_invocation (frame) | |
dd3b648e RP |
328 | |
329 | /* Define other aspects of the stack frame. */ | |
330 | ||
e140f1da JG |
331 | #define FRAME_SAVED_PC(FRAME) \ |
332 | frame_saved_pc (FRAME) | |
333 | extern CORE_ADDR frame_saved_pc (); | |
dd3b648e | 334 | |
e140f1da JG |
335 | #define FRAME_ARGS_ADDRESS(fi) \ |
336 | frame_args_address (fi) | |
337 | extern CORE_ADDR frame_args_address (); | |
dd3b648e | 338 | |
e140f1da JG |
339 | #define FRAME_LOCALS_ADDRESS(fi) \ |
340 | frame_locals_address (fi) | |
341 | extern CORE_ADDR frame_locals_address (); | |
dd3b648e RP |
342 | |
343 | /* Return number of args passed to a frame. | |
344 | Can return -1, meaning no way to tell. */ | |
345 | ||
346 | #define FRAME_NUM_ARGS(numargs, fi) ((numargs) = -1) | |
347 | ||
348 | /* Return number of bytes at start of arglist that are not really args. */ | |
349 | ||
350 | #define FRAME_ARGS_SKIP 0 | |
351 | ||
352 | /* Put here the code to store, into a struct frame_saved_regs, | |
353 | the addresses of the saved registers of frame described by FRAME_INFO. | |
354 | This includes special registers such as pc and fp saved in special | |
355 | ways in the stack frame. sp is even more special: | |
356 | the address we return for it IS the sp for the next frame. */ | |
357 | ||
358 | /* On the 88k, parameter registers get stored into the so called "homing" | |
359 | area. This *always* happens when you compiled with GCC and use -g. | |
360 | Also, (with GCC and -g) the saving of the parameter register values | |
361 | always happens right within the function prologue code, so these register | |
362 | values can generally be relied upon to be already copied into their | |
363 | respective homing slots by the time you will normally try to look at | |
364 | them (we hope). | |
365 | ||
366 | Note that homing area stack slots are always at *positive* offsets from | |
367 | the frame pointer. Thus, the homing area stack slots for the parameter | |
368 | registers (passed values) for a given function are actually part of the | |
369 | frame area of the caller. This is unusual, but it should not present | |
370 | any special problems for GDB. | |
371 | ||
372 | Note also that on the 88k, we are only interested in finding the | |
373 | registers that might have been saved in memory. This is a subset of | |
374 | the whole set of registers because the standard calling sequence allows | |
375 | the called routine to clobber many registers. | |
376 | ||
377 | We could manage to locate values for all of the so called "preserved" | |
378 | registers (some of which may get saved within any particular frame) but | |
379 | that would require decoding all of the tdesc information. Tht would be | |
380 | nice information for GDB to have, but it is not strictly manditory if we | |
381 | can live without the ability to look at values within (or backup to) | |
382 | previous frames. | |
383 | */ | |
384 | ||
385 | #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \ | |
386 | frame_find_saved_regs (frame_info, &frame_saved_regs) | |
387 | ||
388 | \f | |
8aa13b87 JK |
389 | /* There is not currently a functioning way to call functions in the |
390 | inferior. */ | |
391 | ||
392 | /* But if there was this is where we'd put the call dummy. */ | |
393 | /* #define CALL_DUMMY_LOCATION AFTER_TEXT_END */ | |
394 | ||
dd3b648e RP |
395 | /* When popping a frame on the 88k (say when doing a return command), the |
396 | calling function only expects to have the "preserved" registers restored. | |
397 | Thus, those are the only ones that we even try to restore here. */ | |
398 | ||
dd3b648e | 399 | #define POP_FRAME pop_frame () |
e140f1da | 400 | extern void pop_frame (); |