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+/*
+Date: Thu, 2 Apr 87 00:02:42 EST
+From: crl@maxwell.physics.purdue.edu (Charles R. LaBrec)
+Message-Id: <8704020502.AA01744@maxwell.physics.purdue.edu>
+To: bug-gdb@prep.ai.mit.edu
+Subject: gdb for ISI Optimum V
+
+Here is an m-isi-ov.h file for gdb version 2.1. It supports the 68881
+registers, and tracks down the function prologue (since the ISI cc
+puts it at the end of the function and branches to it if not
+optimizing). Also included are diffs to core.c, findvar.c, and
+inflow.c, since the original code assumed that registers are an int in
+the user struct, which isn't the case for 68020's with 68881's (and
+not using the NEW_SUN_PTRACE). I have not fixed the bugs associated
+with the other direction (writing registers back to the user struct).
+I have also included a diff that turns m68k-pinsn.c into isi-pinsn.c,
+which is needed since the 3.05 release of as does not understand
+floating point ops, and it compiles incorrectly under "cc -20"
+
+I have used gdb for a while now, and it seems to work relatively well,
+but I do not guarantee that it is perfect. The more that use it, the
+faster the bugs will get shaken out. One bug I know of is not in gdb,
+but in the assembler. It seems to screw up the .stabs of variables.
+For externs, this is not important since gdb uses the global symbol
+value, but for statics, this makes gdb unable to find them. I am
+currently trying to track it down.
+
+As an aside, I notice that only global functions are used as symbols
+to print as relative addresses, i.e. "<function + offset>", and not
+static functions, which end up printing as large offsets from the last
+global one. Would there be a problem if static functions were also
+recorded as misc functions in read_dbx_symtab?
+
+Charles LaBrec
+crl @ maxwell.physics.purdue.edu
+
+ Definitions to make GDB run on a ISI Optimum V (3.05) under 4.2bsd.
+
+ Copyright (C) 1987 Free Software Foundation, Inc.
+
+GDB is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY. No author or distributor accepts responsibility to anyone
+for the consequences of using it or for whether it serves any
+particular purpose or works at all, unless he says so in writing.
+Refer to the GDB General Public License for full details.
+
+Everyone is granted permission to copy, modify and redistribute GDB,
+but only under the conditions described in the GDB General Public
+License. A copy of this license is supposed to have been given to you
+along with GDB so you can know your rights and responsibilities. It
+should be in a file named COPYING. Among other things, the copyright
+notice and this notice must be preserved on all copies.
+
+In other words, go ahead and share GDB, but don't try to stop
+anyone else from sharing it farther. Help stamp out software hoarding!
+*/
+
+
+/* Identify this machine */
+#ifndef ISI68K
+#define ISI68K
+#endif
+
+/* Define this if the C compiler puts an underscore at the front
+ of external names before giving them to the linker. */
+
+#define NAMES_HAVE_UNDERSCORE
+
+/* Debugger information will be in DBX format. */
+
+#define READ_DBX_FORMAT
+
+/* Offset from address of function to start of its code.
+ Zero on most machines. */
+
+#define FUNCTION_START_OFFSET 0
+
+/* Advance PC across any function entry prologue instructions
+ to reach some "real" code. */
+
+#define SKIP_PROLOGUE(pc) \
+{ register int op = read_memory_integer (pc, 2); \
+ if (op == 0047126) \
+ pc += 4; /* Skip link #word */ \
+ else if (op == 0044016) \
+ pc += 6; /* Skip link #long */ \
+ else if (op == 0060000) \
+ pc += 4; /* Skip bra #word */ \
+ else if (op == 00600377) \
+ pc += 6; /* skip bra #long */ \
+ else if ((op & 0177400) == 0060000) \
+ pc += 2; /* skip bra #char */ \
+}
+
+
+/* Immediately after a function call, return the saved pc.
+ Can't always go through the frames for this because on some machines
+ the new frame is not set up until the new function executes
+ some instructions. */
+
+#define SAVED_PC_AFTER_CALL(frame) \
+read_memory_integer (read_register (SP_REGNUM), 4)
+
+/* This is the amount to subtract from u.u_ar0
+ to get the offset in the core file of the register values. */
+
+#define KERNEL_U_ADDR 0x10800000
+
+/* Address of end of stack space. */
+
+#define STACK_END_ADDR 0x10000000
+
+/* Stack grows downward. */
+
+#define INNER_THAN <
+
+/* Sequence of bytes for breakpoint instruction. */
+
+#define BREAKPOINT {0x4e, 0x4f}
+
+/* Data segment starts at etext rounded up to DATAROUND in {N,Z}MAGIC files */
+
+#define DATAROUND 0x20000
+#define N_DATADDR(hdr) (hdr.a_magic != OMAGIC ? \
+ (hdr.a_text + DATAROUND) & ~(DATAROUND-1) : hdr.a_text)
+
+/* Text segment starts at sizeof (struct exec) in {N,Z}MAGIC files */
+
+#define N_TXTADDR(hdr) (hdr.a_magic != OMAGIC ? sizeof (struct exec) : 0)
+
+/* Amount PC must be decremented by after a breakpoint.
+ This is often the number of bytes in BREAKPOINT
+ but not always.
+ On the ISI, the kernel resets the pc to the trap instr */
+
+#define DECR_PC_AFTER_BREAK 0
+
+/* Nonzero if instruction at PC is a return instruction. */
+
+#define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 2) == 0x4e75)
+
+/* Return 1 if P points to an invalid floating point value. */
+
+#define INVALID_FLOAT(p, len) 0 /* Just a first guess; not checked */
+
+/* Largest integer type */
+#define LONGEST long
+
+/* Name of the builtin type for the LONGEST type above. */
+#define BUILTIN_TYPE_LONGEST builtin_type_long
+
+/* Say how long registers are. */
+
+#define REGISTER_TYPE long
+
+/* Number of machine registers */
+
+#define NUM_REGS 29
+
+/* Initializer for an array of names of registers.
+ There should be NUM_REGS strings in this initializer. */
+
+#define REGISTER_NAMES \
+ {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
+ "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
+ "ps", "pc", \
+ "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
+ "fpcontrol", "fpstatus", "fpiaddr" }
+
+/* Register numbers of various important registers.
+ Note that some of these values are "real" register numbers,
+ and correspond to the general registers of the machine,
+ and some are "phony" register numbers which are too large
+ to be actual register numbers as far as the user is concerned
+ but do serve to get the desired values when passed to read_register. */
+
+#define FP_REGNUM 14 /* Contains address of executing stack frame */
+#define SP_REGNUM 15 /* Contains address of top of stack */
+#define PS_REGNUM 16 /* Contains processor status */
+#define PC_REGNUM 17 /* Contains program counter */
+#define FP0_REGNUM 18 /* Floating point register 0 */
+#define FPC_REGNUM 26 /* 68881 control register */
+
+#ifdef BSD43_ISI40D
+#define BLOCKFUDGE 0x400000
+#else
+#define BLOCKFUDGE 0
+#endif
+#define REGISTER_U_ADDR(addr, blockend, regno) \
+{ blockend -= BLOCKFUDGE; \
+ if (regno < 2) addr = blockend - 0x18 + regno * 4; \
+ else if (regno < 8) addr = blockend - 0x54 + regno * 4; \
+ else if (regno < 10) addr = blockend - 0x30 + regno * 4;\
+ else if (regno < 15) addr = blockend - 0x5c + regno * 4;\
+ else if (regno < 16) addr = blockend - 0x1c; \
+ else if (regno < 18) addr = blockend - 0x44 + regno * 4;\
+ else if (regno < 26) addr = (int) ((struct user *)0)->u_68881_regs \
+ + (regno - 18) * 12; \
+ else if (regno < 29) addr = (int) ((struct user *)0)->u_68881_regs \
+ + 8 * 12 + (regno - 26) * 4; \
+}
+
+/* Total amount of space needed to store our copies of the machine's
+ register state, the array `registers'. */
+#define REGISTER_BYTES (16*4+8*12+8+20)
+
+/* Index within `registers' of the first byte of the space for
+ register N. */
+
+#define REGISTER_BYTE(N) \
+ ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168 \
+ : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72 \
+ : (N) * 4)
+
+/* Number of bytes of storage in the actual machine representation
+ for register N. On the 68000, all regs are 4 bytes
+ except the floating point regs which are 12 bytes. */
+
+#define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
+
+/* Number of bytes of storage in the program's representation
+ for register N. On the 68000, all regs are 4 bytes
+ except the floating point regs which are 8-byte doubles. */
+
+#define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
+
+/* Largest value REGISTER_RAW_SIZE can have. */
+
+#define MAX_REGISTER_RAW_SIZE 12
+
+/* Largest value REGISTER_VIRTUAL_SIZE can have. */
+
+#define MAX_REGISTER_VIRTUAL_SIZE 8
+
+/* Nonzero if register N requires conversion
+ from raw format to virtual format. */
+
+#define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
+
+/* Convert data from raw format for register REGNUM
+ to virtual format for register REGNUM. */
+
+#define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
+{ if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM) \
+ convert_from_68881 ((FROM), (TO)); \
+ else \
+ bcopy ((FROM), (TO), 4); }
+
+/* Convert data from virtual format for register REGNUM
+ to raw format for register REGNUM. */
+
+#define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
+{ if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM) \
+ convert_to_68881 ((FROM), (TO)); \
+ else \
+ bcopy ((FROM), (TO), 4); }
+
+/* Return the GDB type object for the "standard" data type
+ of data in register N. */
+
+#define REGISTER_VIRTUAL_TYPE(N) \
+ (((unsigned)(N) - FP0_REGNUM) < 8 ? builtin_type_double : builtin_type_int)
+
+/* Store the address of the place in which to copy the structure the
+ subroutine will return. This is called from call_function. */
+
+#define STORE_STRUCT_RETURN(ADDR, SP) \
+ { write_register (9, (ADDR)); }
+
+/* Extract from an array REGBUF containing the (raw) register state
+ a function return value of type TYPE, and copy that, in virtual format,
+ into VALBUF. */
+
+#define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
+ bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE))
+
+/* Write into appropriate registers a function return value
+ of type TYPE, given in virtual format. */
+
+#define STORE_RETURN_VALUE(TYPE,VALBUF) \
+ write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
+
+/* Extract from an array REGBUF containing the (raw) register state
+ the address in which a function should return its structure value,
+ as a CORE_ADDR (or an expression that can be used as one). */
+
+#define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
+
+/* Describe the pointer in each stack frame to the previous stack frame
+ (its caller). */
+
+/* FRAME_CHAIN takes a frame's nominal address
+ and produces the frame's chain-pointer.
+
+ FRAME_CHAIN_COMBINE takes the chain pointer and the frame's nominal address
+ and produces the nominal address of the caller frame.
+
+ However, if FRAME_CHAIN_VALID returns zero,
+ it means the given frame is the outermost one and has no caller.
+ In that case, FRAME_CHAIN_COMBINE is not used. */
+
+/* In the case of the ISI, the frame's nominal address
+ is the address of a 4-byte word containing the calling frame's address. */
+
+#define FRAME_CHAIN(thisframe) (read_memory_integer ((thisframe)->frame, 4))
+
+#define FRAME_CHAIN_VALID(chain, thisframe) \
+ (chain != 0 && (FRAME_SAVED_PC (thisframe) >= first_object_file_end))
+
+#define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
+
+/* Define other aspects of the stack frame. */
+
+#define FRAME_SAVED_PC(FRAME) (read_memory_integer ((FRAME)->frame + 4, 4))
+
+#define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
+
+#define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
+
+/* Return number of args passed to a frame.
+ Can return -1, meaning no way to tell. */
+
+#define FRAME_NUM_ARGS(val, fi) \
+{ register CORE_ADDR pc = FRAME_SAVED_PC (fi); \
+ register int insn = 0177777 & read_memory_integer (pc, 2); \
+ val = 0; \
+ if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */ \
+ val = read_memory_integer (pc + 2, 2); \
+ else if ((insn & 0170777) == 0050217 /* addql #N, sp */ \
+ || (insn & 0170777) == 0050117) /* addqw */ \
+ { val = (insn >> 9) & 7; if (val == 0) val = 8; } \
+ else if (insn == 0157774) /* addal #WW, sp */ \
+ val = read_memory_integer (pc + 2, 4); \
+ val >>= 2; }
+
+/* Return number of bytes at start of arglist that are not really args. */
+
+#define FRAME_ARGS_SKIP 8
+
+/* Put here the code to store, into a struct frame_saved_regs,
+ the addresses of the saved registers of frame described by FRAME_INFO.
+ This includes special registers such as pc and fp saved in special
+ ways in the stack frame. sp is even more special:
+ the address we return for it IS the sp for the next frame. */
+
+#define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
+{ register int regnum; \
+ register int regmask; \
+ register CORE_ADDR next_addr; \
+ register CORE_ADDR pc; \
+ register int insn; \
+ register int offset; \
+ bzero (&frame_saved_regs, sizeof frame_saved_regs); \
+ if ((frame_info)->pc >= (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM*4 - 8*12 - 4 \
+ && (frame_info)->pc <= (frame_info)->frame) \
+ { next_addr = (frame_info)->frame; \
+ pc = (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 8*12 - 4; }\
+ else \
+ { pc = get_pc_function_start ((frame_info)->pc); \
+ /* Verify we have a link a6 instruction next, \
+ or a branch followed by a link a6 instruction; \
+ if not we lose. If we win, find the address above the saved \
+ regs using the amount of storage from the link instruction. */\
+retry: \
+ insn = read_memory_integer (pc, 2); \
+ if (insn == 044016) \
+ next_addr = (frame_info)->frame - read_memory_integer (pc += 2, 4), pc+=4; \
+ else if (insn == 047126) \
+ next_addr = (frame_info)->frame - read_memory_integer (pc += 2, 2), pc+=2; \
+ else if ((insn & 0177400) == 060000) /* bra insn */ \
+ { offset = insn & 0377; \
+ pc += 2; /* advance past bra */ \
+ if (offset == 0) /* bra #word */ \
+ offset = read_memory_integer (pc, 2), pc += 2; \
+ else if (offset == 0377) /* bra #long */ \
+ offset = read_memory_integer (pc, 4), pc += 4; \
+ pc += offset; \
+ goto retry; \
+ } else goto lose; \
+ /* If have an addal #-n, sp next, adjust next_addr. */ \
+ if ((0177777 & read_memory_integer (pc, 2)) == 0157774) \
+ next_addr += read_memory_integer (pc += 2, 4), pc += 4; \
+ } \
+ /* next should be a moveml to (sp) or -(sp) or a movl r,-(sp) */ \
+ insn = read_memory_integer (pc, 2), pc += 2; \
+ regmask = read_memory_integer (pc, 2); \
+ if ((insn & 0177760) == 022700) /* movl rn, (sp) */ \
+ (frame_saved_regs).regs[(insn&7) + ((insn&010)?8:0)] = next_addr; \
+ else if ((insn & 0177760) == 024700) /* movl rn, -(sp) */ \
+ (frame_saved_regs).regs[(insn&7) + ((insn&010)?8:0)] = next_addr-=4; \
+ else if (insn == 0044327) /* moveml mask, (sp) */ \
+ { pc += 2; \
+ /* Regmask's low bit is for register 0, the first written */ \
+ next_addr -= 4; \
+ for (regnum = 0; regnum < 16; regnum++, regmask >>= 1) \
+ if (regmask & 1) \
+ (frame_saved_regs).regs[regnum] = (next_addr += 4); \
+ } else if (insn == 0044347) /* moveml mask, -(sp) */ \
+ { pc += 2; \
+ /* Regmask's low bit is for register 15, the first pushed */ \
+ for (regnum = 15; regnum >= 0; regnum--, regmask >>= 1) \
+ if (regmask & 1) \
+ (frame_saved_regs).regs[regnum] = (next_addr -= 4); } \
+ /* clrw -(sp); movw ccr,-(sp) may follow. */ \
+ if (read_memory_integer (pc, 2) == 041147 \
+ && read_memory_integer (pc+2, 2) == 042347) \
+ (frame_saved_regs).regs[PS_REGNUM] = (next_addr -= 4); \
+ lose: ; \
+ (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 8; \
+ (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame; \
+ (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4; \
+}
+
+/* Compensate for lack of `vprintf' function. */
+#define vprintf(format, ap) _doprnt (format, ap, stdout)
+
+/* Things needed for making the inferior call functions. */
+
+/* Push an empty stack frame, to record the current PC, etc. */
+
+#define PUSH_DUMMY_FRAME \
+{ register CORE_ADDR sp = read_register (SP_REGNUM); \
+ register int regnum; \
+ char raw_buffer[12]; \
+ sp = push_word (sp, read_register (PC_REGNUM)); \
+ sp = push_word (sp, read_register (FP_REGNUM)); \
+ write_register (FP_REGNUM, sp); \
+ for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--) \
+ { read_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12); \
+ sp = push_bytes (sp, raw_buffer, 12); } \
+ for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--) \
+ sp = push_word (sp, read_register (regnum)); \
+ sp = push_word (sp, read_register (PS_REGNUM)); \
+ write_register (SP_REGNUM, sp); }
+
+/* Discard from the stack the innermost frame, restoring all registers. */
+
+#define POP_FRAME \
+{ register FRAME frame = get_current_frame (); \
+ register CORE_ADDR fp; \
+ register int regnum; \
+ struct frame_saved_regs fsr; \
+ struct frame_info *fi; \
+ char raw_buffer[12]; \
+ fi = get_frame_info (frame); \
+ fp = fi->frame; \
+ get_frame_saved_regs (fi, &fsr); \
+ for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--) \
+ if (fsr.regs[regnum]) \
+ { read_memory (fsr.regs[regnum], raw_buffer, 12); \
+ write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12); }\
+ for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--) \
+ if (fsr.regs[regnum]) \
+ write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); \
+ if (fsr.regs[PS_REGNUM]) \
+ write_register (PS_REGNUM, read_memory_integer (fsr.regs[PS_REGNUM], 4)); \
+ write_register (FP_REGNUM, read_memory_integer (fp, 4)); \
+ write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); \
+ write_register (SP_REGNUM, fp + 8); \
+ flush_cached_frames (); \
+ set_current_frame ( create_new_frame (read_register (FP_REGNUM), \
+ read_pc ())); }
+
+/* This sequence of words is the instructions
+ fmovem #<f0-f7>,-(sp)
+ moveml 0xfffc,-(sp)
+ clrw -(sp)
+ movew ccr,-(sp)
+ /..* The arguments are pushed at this point by GDB;
+ no code is needed in the dummy for this.
+ The CALL_DUMMY_START_OFFSET gives the position of
+ the following jsr instruction. *../
+ jsr @#32323232
+ addl #69696969,sp
+ bpt
+ nop
+Note this is 24 bytes.
+We actually start executing at the jsr, since the pushing of the
+registers is done by PUSH_DUMMY_FRAME. If this were real code,
+the arguments for the function called by the jsr would be pushed
+between the moveml and the jsr, and we could allow it to execute through.
+But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
+and we cannot allow the moveml to push the registers again lest they be
+taken for the arguments. */
+
+#define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, 0x4e4f4e71}
+
+#define CALL_DUMMY_LENGTH 28
+
+#define CALL_DUMMY_START_OFFSET 12
+
+/* Insert the specified number of args and function address
+ into a call sequence of the above form stored at DUMMYNAME. */
+
+#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, type) \
+{ *(int *)((char *) dummyname + 20) = nargs * 4; \
+ *(int *)((char *) dummyname + 14) = fun; }
+
+/* Interface definitions for kernel debugger KDB. */
+
+/* Map machine fault codes into signal numbers.
+ First subtract 0, divide by 4, then index in a table.
+ Faults for which the entry in this table is 0
+ are not handled by KDB; the program's own trap handler
+ gets to handle then. */
+
+#define FAULT_CODE_ORIGIN 0
+#define FAULT_CODE_UNITS 4
+#define FAULT_TABLE \
+{ 0, 0, 0, 0, SIGTRAP, 0, 0, 0, \
+ 0, SIGTRAP, 0, 0, 0, 0, 0, SIGKILL, \
+ 0, 0, 0, 0, 0, 0, 0, 0, \
+ SIGILL }
+
+/* Start running with a stack stretching from BEG to END.
+ BEG and END should be symbols meaningful to the assembler.
+ This is used only for kdb. */
+
+#define INIT_STACK(beg, end) \
+{ asm (".globl end"); \
+ asm ("movl $ end, sp"); \
+ asm ("clrl fp"); }
+
+/* Push the frame pointer register on the stack. */
+#define PUSH_FRAME_PTR \
+ asm ("movel fp, -(sp)");
+
+/* Copy the top-of-stack to the frame pointer register. */
+#define POP_FRAME_PTR \
+ asm ("movl (sp), fp");
+
+/* After KDB is entered by a fault, push all registers
+ that GDB thinks about (all NUM_REGS of them),
+ so that they appear in order of ascending GDB register number.
+ The fault code will be on the stack beyond the last register. */
+
+#define PUSH_REGISTERS \
+{ asm ("clrw -(sp)"); \
+ asm ("pea 10(sp)"); \
+ asm ("movem $ 0xfffe,-(sp)"); }
+
+/* Assuming the registers (including processor status) have been
+ pushed on the stack in order of ascending GDB register number,
+ restore them and return to the address in the saved PC register. */
+
+#define POP_REGISTERS \
+{ asm ("subil $8,28(sp)"); \
+ asm ("movem (sp),$ 0xffff"); \
+ asm ("rte"); }