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+/* Target-machine dependent code for the Intel 960
+ Copyright 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+ Contributed by Intel Corporation.
+ examine_prologue and other parts contributed by Wind River Systems.
+
+This file is part of GDB.
+
+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. */
+
+#include "defs.h"
+#include "symtab.h"
+#include "value.h"
+#include "frame.h"
+#include "floatformat.h"
+#include "target.h"
+#include "gdbcore.h"
+
+static CORE_ADDR next_insn PARAMS ((CORE_ADDR memaddr,
+ unsigned int *pword1,
+ unsigned int *pword2));
+
+/* Does the specified function use the "struct returning" convention
+ or the "value returning" convention? The "value returning" convention
+ almost invariably returns the entire value in registers. The
+ "struct returning" convention often returns the entire value in
+ memory, and passes a pointer (out of or into the function) saying
+ where the value (is or should go).
+
+ Since this sometimes depends on whether it was compiled with GCC,
+ this is also an argument. This is used in call_function to build a
+ stack, and in value_being_returned to print return values.
+
+ On i960, a structure is returned in registers g0-g3, if it will fit.
+ If it's more than 16 bytes long, g13 pointed to it on entry. */
+
+int
+i960_use_struct_convention (gcc_p, type)
+ int gcc_p;
+ struct type *type;
+{
+ return (TYPE_LENGTH (type) > 16);
+}
+
+/* gdb960 is always running on a non-960 host. Check its characteristics.
+ This routine must be called as part of gdb initialization. */
+
+static void
+check_host()
+{
+ int i;
+
+ static struct typestruct {
+ int hostsize; /* Size of type on host */
+ int i960size; /* Size of type on i960 */
+ char *typename; /* Name of type, for error msg */
+ } types[] = {
+ { sizeof(short), 2, "short" },
+ { sizeof(int), 4, "int" },
+ { sizeof(long), 4, "long" },
+ { sizeof(float), 4, "float" },
+ { sizeof(double), 8, "double" },
+ { sizeof(char *), 4, "pointer" },
+ };
+#define TYPELEN (sizeof(types) / sizeof(struct typestruct))
+
+ /* Make sure that host type sizes are same as i960
+ */
+ for ( i = 0; i < TYPELEN; i++ ){
+ if ( types[i].hostsize != types[i].i960size ){
+ printf_unfiltered("sizeof(%s) != %d: PROCEED AT YOUR OWN RISK!\n",
+ types[i].typename, types[i].i960size );
+ }
+
+ }
+}
+
+/* Examine an i960 function prologue, recording the addresses at which
+ registers are saved explicitly by the prologue code, and returning
+ the address of the first instruction after the prologue (but not
+ after the instruction at address LIMIT, as explained below).
+
+ LIMIT places an upper bound on addresses of the instructions to be
+ examined. If the prologue code scan reaches LIMIT, the scan is
+ aborted and LIMIT is returned. This is used, when examining the
+ prologue for the current frame, to keep examine_prologue () from
+ claiming that a given register has been saved when in fact the
+ instruction that saves it has not yet been executed. LIMIT is used
+ at other times to stop the scan when we hit code after the true
+ function prologue (e.g. for the first source line) which might
+ otherwise be mistaken for function prologue.
+
+ The format of the function prologue matched by this routine is
+ derived from examination of the source to gcc960 1.21, particularly
+ the routine i960_function_prologue (). A "regular expression" for
+ the function prologue is given below:
+
+ (lda LRn, g14
+ mov g14, g[0-7]
+ (mov 0, g14) | (lda 0, g14))?
+
+ (mov[qtl]? g[0-15], r[4-15])*
+ ((addo [1-31], sp, sp) | (lda n(sp), sp))?
+ (st[qtl]? g[0-15], n(fp))*
+
+ (cmpobne 0, g14, LFn
+ mov sp, g14
+ lda 0x30(sp), sp
+ LFn: stq g0, (g14)
+ stq g4, 0x10(g14)
+ stq g8, 0x20(g14))?
+
+ (st g14, n(fp))?
+ (mov g13,r[4-15])?
+*/
+
+/* Macros for extracting fields from i960 instructions. */
+
+#define BITMASK(pos, width) (((0x1 << (width)) - 1) << (pos))
+#define EXTRACT_FIELD(val, pos, width) ((val) >> (pos) & BITMASK (0, width))
+
+#define REG_SRC1(insn) EXTRACT_FIELD (insn, 0, 5)
+#define REG_SRC2(insn) EXTRACT_FIELD (insn, 14, 5)
+#define REG_SRCDST(insn) EXTRACT_FIELD (insn, 19, 5)
+#define MEM_SRCDST(insn) EXTRACT_FIELD (insn, 19, 5)
+#define MEMA_OFFSET(insn) EXTRACT_FIELD (insn, 0, 12)
+
+/* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
+ is not the address of a valid instruction, the address of the next
+ instruction beyond ADDR otherwise. *PWORD1 receives the first word
+ of the instruction, and (for two-word instructions), *PWORD2 receives
+ the second. */
+
+#define NEXT_PROLOGUE_INSN(addr, lim, pword1, pword2) \
+ (((addr) < (lim)) ? next_insn (addr, pword1, pword2) : 0)
+
+static CORE_ADDR
+examine_prologue (ip, limit, frame_addr, fsr)
+ register CORE_ADDR ip;
+ register CORE_ADDR limit;
+ CORE_ADDR frame_addr;
+ struct frame_saved_regs *fsr;
+{
+ register CORE_ADDR next_ip;
+ register int src, dst;
+ register unsigned int *pcode;
+ unsigned int insn1, insn2;
+ int size;
+ int within_leaf_prologue;
+ CORE_ADDR save_addr;
+ static unsigned int varargs_prologue_code [] =
+ {
+ 0x3507a00c, /* cmpobne 0x0, g14, LFn */
+ 0x5cf01601, /* mov sp, g14 */
+ 0x8c086030, /* lda 0x30(sp), sp */
+ 0xb2879000, /* LFn: stq g0, (g14) */
+ 0xb2a7a010, /* stq g4, 0x10(g14) */
+ 0xb2c7a020 /* stq g8, 0x20(g14) */
+ };
+
+ /* Accept a leaf procedure prologue code fragment if present.
+ Note that ip might point to either the leaf or non-leaf
+ entry point; we look for the non-leaf entry point first: */
+
+ within_leaf_prologue = 0;
+ if ((next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2))
+ && ((insn1 & 0xfffff000) == 0x8cf00000 /* lda LRx, g14 (MEMA) */
+ || (insn1 & 0xfffffc60) == 0x8cf03000)) /* lda LRx, g14 (MEMB) */
+ {
+ within_leaf_prologue = 1;
+ next_ip = NEXT_PROLOGUE_INSN (next_ip, limit, &insn1, &insn2);
+ }
+
+ /* Now look for the prologue code at a leaf entry point: */
+
+ if (next_ip
+ && (insn1 & 0xff87ffff) == 0x5c80161e /* mov g14, gx */
+ && REG_SRCDST (insn1) <= G0_REGNUM + 7)
+ {
+ within_leaf_prologue = 1;
+ if ((next_ip = NEXT_PROLOGUE_INSN (next_ip, limit, &insn1, &insn2))
+ && (insn1 == 0x8cf00000 /* lda 0, g14 */
+ || insn1 == 0x5cf01e00)) /* mov 0, g14 */
+ {
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
+ within_leaf_prologue = 0;
+ }
+ }
+
+ /* If something that looks like the beginning of a leaf prologue
+ has been seen, but the remainder of the prologue is missing, bail.
+ We don't know what we've got. */
+
+ if (within_leaf_prologue)
+ return (ip);
+
+ /* Accept zero or more instances of "mov[qtl]? gx, ry", where y >= 4.
+ This may cause us to mistake the moving of a register
+ parameter to a local register for the saving of a callee-saved
+ register, but that can't be helped, since with the
+ "-fcall-saved" flag, any register can be made callee-saved. */
+
+ while (next_ip
+ && (insn1 & 0xfc802fb0) == 0x5c000610
+ && (dst = REG_SRCDST (insn1)) >= (R0_REGNUM + 4))
+ {
+ src = REG_SRC1 (insn1);
+ size = EXTRACT_FIELD (insn1, 24, 2) + 1;
+ save_addr = frame_addr + ((dst - R0_REGNUM) * 4);
+ while (size--)
+ {
+ fsr->regs[src++] = save_addr;
+ save_addr += 4;
+ }
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
+ }
+
+ /* Accept an optional "addo n, sp, sp" or "lda n(sp), sp". */
+
+ if (next_ip &&
+ ((insn1 & 0xffffffe0) == 0x59084800 /* addo n, sp, sp */
+ || (insn1 & 0xfffff000) == 0x8c086000 /* lda n(sp), sp (MEMA) */
+ || (insn1 & 0xfffffc60) == 0x8c087400)) /* lda n(sp), sp (MEMB) */
+ {
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
+ }
+
+ /* Accept zero or more instances of "st[qtl]? gx, n(fp)".
+ This may cause us to mistake the copying of a register
+ parameter to the frame for the saving of a callee-saved
+ register, but that can't be helped, since with the
+ "-fcall-saved" flag, any register can be made callee-saved.
+ We can, however, refuse to accept a save of register g14,
+ since that is matched explicitly below. */
+
+ while (next_ip &&
+ ((insn1 & 0xf787f000) == 0x9287e000 /* stl? gx, n(fp) (MEMA) */
+ || (insn1 & 0xf787fc60) == 0x9287f400 /* stl? gx, n(fp) (MEMB) */
+ || (insn1 & 0xef87f000) == 0xa287e000 /* st[tq] gx, n(fp) (MEMA) */
+ || (insn1 & 0xef87fc60) == 0xa287f400) /* st[tq] gx, n(fp) (MEMB) */
+ && ((src = MEM_SRCDST (insn1)) != G14_REGNUM))
+ {
+ save_addr = frame_addr + ((insn1 & BITMASK (12, 1))
+ ? insn2 : MEMA_OFFSET (insn1));
+ size = (insn1 & BITMASK (29, 1)) ? ((insn1 & BITMASK (28, 1)) ? 4 : 3)
+ : ((insn1 & BITMASK (27, 1)) ? 2 : 1);
+ while (size--)
+ {
+ fsr->regs[src++] = save_addr;
+ save_addr += 4;
+ }
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
+ }
+
+ /* Accept the varargs prologue code if present. */
+
+ size = sizeof (varargs_prologue_code) / sizeof (int);
+ pcode = varargs_prologue_code;
+ while (size-- && next_ip && *pcode++ == insn1)
+ {
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
+ }
+
+ /* Accept an optional "st g14, n(fp)". */
+
+ if (next_ip &&
+ ((insn1 & 0xfffff000) == 0x92f7e000 /* st g14, n(fp) (MEMA) */
+ || (insn1 & 0xfffffc60) == 0x92f7f400)) /* st g14, n(fp) (MEMB) */
+ {
+ fsr->regs[G14_REGNUM] = frame_addr + ((insn1 & BITMASK (12, 1))
+ ? insn2 : MEMA_OFFSET (insn1));
+ ip = next_ip;
+ next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
+ }
+
+ /* Accept zero or one instance of "mov g13, ry", where y >= 4.
+ This is saving the address where a struct should be returned. */
+
+ if (next_ip
+ && (insn1 & 0xff802fbf) == 0x5c00061d
+ && (dst = REG_SRCDST (insn1)) >= (R0_REGNUM + 4))
+ {
+ save_addr = frame_addr + ((dst - R0_REGNUM) * 4);
+ fsr->regs[G0_REGNUM+13] = save_addr;
+ ip = next_ip;
+#if 0 /* We'll need this once there is a subsequent instruction examined. */
+ next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
+#endif
+ }
+
+ return (ip);
+}
+
+/* Given an ip value corresponding to the start of a function,
+ return the ip of the first instruction after the function
+ prologue. */
+
+CORE_ADDR
+skip_prologue (ip)
+ CORE_ADDR (ip);
+{
+ struct frame_saved_regs saved_regs_dummy;
+ struct symtab_and_line sal;
+ CORE_ADDR limit;
+
+ sal = find_pc_line (ip, 0);
+ limit = (sal.end) ? sal.end : 0xffffffff;
+
+ return (examine_prologue (ip, limit, (CORE_ADDR) 0, &saved_regs_dummy));
+}
+
+/* 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.
+
+ We cache the result of doing this in the frame_obstack, since it is
+ fairly expensive. */
+
+void
+frame_find_saved_regs (fi, fsr)
+ struct frame_info *fi;
+ struct frame_saved_regs *fsr;
+{
+ register CORE_ADDR next_addr;
+ register CORE_ADDR *saved_regs;
+ register int regnum;
+ register struct frame_saved_regs *cache_fsr;
+ CORE_ADDR ip;
+ struct symtab_and_line sal;
+ CORE_ADDR limit;
+
+ if (!fi->fsr)
+ {
+ cache_fsr = (struct frame_saved_regs *)
+ frame_obstack_alloc (sizeof (struct frame_saved_regs));
+ memset (cache_fsr, '\0', sizeof (struct frame_saved_regs));
+ fi->fsr = cache_fsr;
+
+ /* Find the start and end of the function prologue. If the PC
+ is in the function prologue, we only consider the part that
+ has executed already. */
+
+ ip = get_pc_function_start (fi->pc);
+ sal = find_pc_line (ip, 0);
+ limit = (sal.end && sal.end < fi->pc) ? sal.end: fi->pc;
+
+ examine_prologue (ip, limit, fi->frame, cache_fsr);
+
+ /* Record the addresses at which the local registers are saved.
+ Strictly speaking, we should only do this for non-leaf procedures,
+ but no one will ever look at these values if it is a leaf procedure,
+ since local registers are always caller-saved. */
+
+ next_addr = (CORE_ADDR) fi->frame;
+ saved_regs = cache_fsr->regs;
+ for (regnum = R0_REGNUM; regnum <= R15_REGNUM; regnum++)
+ {
+ *saved_regs++ = next_addr;
+ next_addr += 4;
+ }
+
+ cache_fsr->regs[FP_REGNUM] = cache_fsr->regs[PFP_REGNUM];
+ }
+
+ *fsr = *fi->fsr;
+
+ /* Fetch the value of the sp from memory every time, since it
+ is conceivable that it has changed since the cache was flushed.
+ This unfortunately undoes much of the savings from caching the
+ saved register values. I suggest adding an argument to
+ get_frame_saved_regs () specifying the register number we're
+ interested in (or -1 for all registers). This would be passed
+ through to FRAME_FIND_SAVED_REGS (), permitting more efficient
+ computation of saved register addresses (e.g., on the i960,
+ we don't have to examine the prologue to find local registers).
+ -- markf@wrs.com
+ FIXME, we don't need to refetch this, since the cache is cleared
+ every time the child process is restarted. If GDB itself
+ modifies SP, it has to clear the cache by hand (does it?). -gnu */
+
+ fsr->regs[SP_REGNUM] = read_memory_integer (fsr->regs[SP_REGNUM], 4);
+}
+
+/* Return the address of the argument block for the frame
+ described by FI. Returns 0 if the address is unknown. */
+
+CORE_ADDR
+frame_args_address (fi, must_be_correct)
+ struct frame_info *fi;
+{
+ struct frame_saved_regs fsr;
+ CORE_ADDR ap;
+
+ /* If g14 was saved in the frame by the function prologue code, return
+ the saved value. If the frame is current and we are being sloppy,
+ return the value of g14. Otherwise, return zero. */
+
+ get_frame_saved_regs (fi, &fsr);
+ if (fsr.regs[G14_REGNUM])
+ ap = read_memory_integer (fsr.regs[G14_REGNUM],4);
+ else
+ {
+ if (must_be_correct)
+ return 0; /* Don't cache this result */
+ if (get_next_frame (fi))
+ ap = 0;
+ else
+ ap = read_register (G14_REGNUM);
+ if (ap == 0)
+ ap = fi->frame;
+ }
+ fi->arg_pointer = ap; /* Cache it for next time */
+ return ap;
+}
+
+/* Return the address of the return struct for the frame
+ described by FI. Returns 0 if the address is unknown. */
+
+CORE_ADDR
+frame_struct_result_address (fi)
+ struct frame_info *fi;
+{
+ struct frame_saved_regs fsr;
+ CORE_ADDR ap;
+
+ /* If the frame is non-current, check to see if g14 was saved in the
+ frame by the function prologue code; return the saved value if so,
+ zero otherwise. If the frame is current, return the value of g14.
+
+ FIXME, shouldn't this use the saved value as long as we are past
+ the function prologue, and only use the current value if we have
+ no saved value and are at TOS? -- gnu@cygnus.com */
+
+ if (get_next_frame (fi))
+ {
+ get_frame_saved_regs (fi, &fsr);
+ if (fsr.regs[G13_REGNUM])
+ ap = read_memory_integer (fsr.regs[G13_REGNUM],4);
+ else
+ ap = 0;
+ }
+ else
+ ap = read_register (G13_REGNUM);
+
+ return ap;
+}
+
+/* Return address to which the currently executing leafproc will return,
+ or 0 if ip is not in a leafproc (or if we can't tell if it is).
+
+ Do this by finding the starting address of the routine in which ip lies.
+ If the instruction there is "mov g14, gx" (where x is in [0,7]), this
+ is a leafproc and the return address is in register gx. Well, this is
+ true unless the return address points at a RET instruction in the current
+ procedure, which indicates that we have a 'dual entry' routine that
+ has been entered through the CALL entry point. */
+
+CORE_ADDR
+leafproc_return (ip)
+ CORE_ADDR ip; /* ip from currently executing function */
+{
+ register struct minimal_symbol *msymbol;
+ char *p;
+ int dst;
+ unsigned int insn1, insn2;
+ CORE_ADDR return_addr;
+
+ if ((msymbol = lookup_minimal_symbol_by_pc (ip)) != NULL)
+ {
+ if ((p = strchr(SYMBOL_NAME (msymbol), '.')) && STREQ (p, ".lf"))
+ {
+ if (next_insn (SYMBOL_VALUE_ADDRESS (msymbol), &insn1, &insn2)
+ && (insn1 & 0xff87ffff) == 0x5c80161e /* mov g14, gx */
+ && (dst = REG_SRCDST (insn1)) <= G0_REGNUM + 7)
+ {
+ /* Get the return address. If the "mov g14, gx"
+ instruction hasn't been executed yet, read
+ the return address from g14; otherwise, read it
+ from the register into which g14 was moved. */
+
+ return_addr =
+ read_register ((ip == SYMBOL_VALUE_ADDRESS (msymbol))
+ ? G14_REGNUM : dst);
+
+ /* We know we are in a leaf procedure, but we don't know
+ whether the caller actually did a "bal" to the ".lf"
+ entry point, or a normal "call" to the non-leaf entry
+ point one instruction before. In the latter case, the
+ return address will be the address of a "ret"
+ instruction within the procedure itself. We test for
+ this below. */
+
+ if (!next_insn (return_addr, &insn1, &insn2)
+ || (insn1 & 0xff000000) != 0xa000000 /* ret */
+ || lookup_minimal_symbol_by_pc (return_addr) != msymbol)
+ return (return_addr);
+ }
+ }
+ }
+
+ return (0);
+}
+
+/* Immediately after a function call, return the saved pc.
+ Can't go through the frames for this because on some machines
+ the new frame is not set up until the new function executes
+ some instructions.
+ On the i960, the frame *is* set up immediately after the call,
+ unless the function is a leaf procedure. */
+
+CORE_ADDR
+saved_pc_after_call (frame)
+ struct frame_info *frame;
+{
+ CORE_ADDR saved_pc;
+
+ saved_pc = leafproc_return (get_frame_pc (frame));
+ if (!saved_pc)
+ saved_pc = FRAME_SAVED_PC (frame);
+
+ return saved_pc;
+}
+
+/* Discard from the stack the innermost frame,
+ restoring all saved registers. */
+
+void
+pop_frame ()
+{
+ register struct frame_info *current_fi, *prev_fi;
+ register int i;
+ CORE_ADDR save_addr;
+ CORE_ADDR leaf_return_addr;
+ struct frame_saved_regs fsr;
+ char local_regs_buf[16 * 4];
+
+ current_fi = get_current_frame ();
+
+ /* First, undo what the hardware does when we return.
+ If this is a non-leaf procedure, restore local registers from
+ the save area in the calling frame. Otherwise, load the return
+ address obtained from leafproc_return () into the rip. */
+
+ leaf_return_addr = leafproc_return (current_fi->pc);
+ if (!leaf_return_addr)
+ {
+ /* Non-leaf procedure. Restore local registers, incl IP. */
+ prev_fi = get_prev_frame (current_fi);
+ read_memory (prev_fi->frame, local_regs_buf, sizeof (local_regs_buf));
+ write_register_bytes (REGISTER_BYTE (R0_REGNUM), local_regs_buf,
+ sizeof (local_regs_buf));
+
+ /* Restore frame pointer. */
+ write_register (FP_REGNUM, prev_fi->frame);
+ }
+ else
+ {
+ /* Leaf procedure. Just restore the return address into the IP. */
+ write_register (RIP_REGNUM, leaf_return_addr);
+ }
+
+ /* Now restore any global regs that the current function had saved. */
+ get_frame_saved_regs (current_fi, &fsr);
+ for (i = G0_REGNUM; i < G14_REGNUM; i++)
+ {
+ if (save_addr = fsr.regs[i])
+ write_register (i, read_memory_integer (save_addr, 4));
+ }
+
+ /* Flush the frame cache, create a frame for the new innermost frame,
+ and make it the current frame. */
+
+ flush_cached_frames ();
+}
+
+/* Given a 960 stop code (fault or trace), return the signal which
+ corresponds. */
+
+enum target_signal
+i960_fault_to_signal (fault)
+ int fault;
+{
+ switch (fault)
+ {
+ case 0: return TARGET_SIGNAL_BUS; /* parallel fault */
+ case 1: return TARGET_SIGNAL_UNKNOWN;
+ case 2: return TARGET_SIGNAL_ILL; /* operation fault */
+ case 3: return TARGET_SIGNAL_FPE; /* arithmetic fault */
+ case 4: return TARGET_SIGNAL_FPE; /* floating point fault */
+
+ /* constraint fault. This appears not to distinguish between
+ a range constraint fault (which should be SIGFPE) and a privileged
+ fault (which should be SIGILL). */
+ case 5: return TARGET_SIGNAL_ILL;
+
+ case 6: return TARGET_SIGNAL_SEGV; /* virtual memory fault */
+
+ /* protection fault. This is for an out-of-range argument to
+ "calls". I guess it also could be SIGILL. */
+ case 7: return TARGET_SIGNAL_SEGV;
+
+ case 8: return TARGET_SIGNAL_BUS; /* machine fault */
+ case 9: return TARGET_SIGNAL_BUS; /* structural fault */
+ case 0xa: return TARGET_SIGNAL_ILL; /* type fault */
+ case 0xb: return TARGET_SIGNAL_UNKNOWN; /* reserved fault */
+ case 0xc: return TARGET_SIGNAL_BUS; /* process fault */
+ case 0xd: return TARGET_SIGNAL_SEGV; /* descriptor fault */
+ case 0xe: return TARGET_SIGNAL_BUS; /* event fault */
+ case 0xf: return TARGET_SIGNAL_UNKNOWN; /* reserved fault */
+ case 0x10: return TARGET_SIGNAL_TRAP; /* single-step trace */
+ case 0x11: return TARGET_SIGNAL_TRAP; /* branch trace */
+ case 0x12: return TARGET_SIGNAL_TRAP; /* call trace */
+ case 0x13: return TARGET_SIGNAL_TRAP; /* return trace */
+ case 0x14: return TARGET_SIGNAL_TRAP; /* pre-return trace */
+ case 0x15: return TARGET_SIGNAL_TRAP; /* supervisor call trace */
+ case 0x16: return TARGET_SIGNAL_TRAP; /* breakpoint trace */
+ default: return TARGET_SIGNAL_UNKNOWN;
+ }
+}
+
+/****************************************/
+/* MEM format */
+/****************************************/
+
+struct tabent {
+ char *name;
+ char numops;
+};
+
+static int /* returns instruction length: 4 or 8 */
+mem( memaddr, word1, word2, noprint )
+ unsigned long memaddr;
+ unsigned long word1, word2;
+ int noprint; /* If TRUE, return instruction length, but
+ don't output any text. */
+{
+ int i, j;
+ int len;
+ int mode;
+ int offset;
+ const char *reg1, *reg2, *reg3;
+
+ /* This lookup table is too sparse to make it worth typing in, but not
+ * so large as to make a sparse array necessary. We allocate the
+ * table at runtime, initialize all entries to empty, and copy the
+ * real ones in from an initialization table.
+ *
+ * NOTE: In this table, the meaning of 'numops' is:
+ * 1: single operand
+ * 2: 2 operands, load instruction
+ * -2: 2 operands, store instruction
+ */
+ static struct tabent *mem_tab = NULL;
+/* Opcodes of 0x8X, 9X, aX, bX, and cX must be in the table. */
+#define MEM_MIN 0x80
+#define MEM_MAX 0xcf
+#define MEM_SIZ ((MEM_MAX-MEM_MIN+1) * sizeof(struct tabent))
+
+ static struct { int opcode; char *name; char numops; } mem_init[] = {
+ 0x80, "ldob", 2,
+ 0x82, "stob", -2,
+ 0x84, "bx", 1,
+ 0x85, "balx", 2,
+ 0x86, "callx", 1,
+ 0x88, "ldos", 2,
+ 0x8a, "stos", -2,
+ 0x8c, "lda", 2,
+ 0x90, "ld", 2,
+ 0x92, "st", -2,
+ 0x98, "ldl", 2,
+ 0x9a, "stl", -2,
+ 0xa0, "ldt", 2,
+ 0xa2, "stt", -2,
+ 0xb0, "ldq", 2,
+ 0xb2, "stq", -2,
+ 0xc0, "ldib", 2,
+ 0xc2, "stib", -2,
+ 0xc8, "ldis", 2,
+ 0xca, "stis", -2,
+ 0, NULL, 0
+ };
+
+ if ( mem_tab == NULL ){
+ mem_tab = (struct tabent *) xmalloc( MEM_SIZ );
+ memset( mem_tab, '\0', MEM_SIZ );
+ for ( i = 0; mem_init[i].opcode != 0; i++ ){
+ j = mem_init[i].opcode - MEM_MIN;
+ mem_tab[j].name = mem_init[i].name;
+ mem_tab[j].numops = mem_init[i].numops;
+ }
+ }
+
+ i = ((word1 >> 24) & 0xff) - MEM_MIN;
+ mode = (word1 >> 10) & 0xf;
+
+ if ( (mem_tab[i].name != NULL) /* Valid instruction */
+ && ((mode == 5) || (mode >=12)) ){ /* With 32-bit displacement */
+ len = 8;
+ } else {
+ len = 4;
+ }
+
+ if ( noprint ){
+ return len;
+ }
+ abort ();
+}
+
+/* Read the i960 instruction at 'memaddr' and return the address of
+ the next instruction after that, or 0 if 'memaddr' is not the
+ address of a valid instruction. The first word of the instruction
+ is stored at 'pword1', and the second word, if any, is stored at
+ 'pword2'. */
+
+static CORE_ADDR
+next_insn (memaddr, pword1, pword2)
+ unsigned int *pword1, *pword2;
+ CORE_ADDR memaddr;
+{
+ int len;
+ char buf[8];
+
+ /* Read the two (potential) words of the instruction at once,
+ to eliminate the overhead of two calls to read_memory ().
+ FIXME: Loses if the first one is readable but the second is not
+ (e.g. last word of the segment). */
+
+ read_memory (memaddr, buf, 8);
+ *pword1 = extract_unsigned_integer (buf, 4);
+ *pword2 = extract_unsigned_integer (buf + 4, 4);
+
+ /* Divide instruction set into classes based on high 4 bits of opcode*/
+
+ switch ((*pword1 >> 28) & 0xf)
+ {
+ case 0x0:
+ case 0x1: /* ctrl */
+
+ case 0x2:
+ case 0x3: /* cobr */
+
+ case 0x5:
+ case 0x6:
+ case 0x7: /* reg */
+ len = 4;
+ break;
+
+ case 0x8:
+ case 0x9:
+ case 0xa:
+ case 0xb:
+ case 0xc:
+ len = mem (memaddr, *pword1, *pword2, 1);
+ break;
+
+ default: /* invalid instruction */
+ len = 0;
+ break;
+ }
+
+ if (len)
+ return memaddr + len;
+ else
+ return 0;
+}
+
+/* 'start_frame' is a variable in the MON960 runtime startup routine
+ that contains the frame pointer of the 'start' routine (the routine
+ that calls 'main'). By reading its contents out of remote memory,
+ we can tell where the frame chain ends: backtraces should halt before
+ they display this frame. */
+
+int
+mon960_frame_chain_valid (chain, curframe)
+ CORE_ADDR chain;
+ struct frame_info *curframe;
+{
+ struct symbol *sym;
+ struct minimal_symbol *msymbol;
+
+ /* crtmon960.o is an assembler module that is assumed to be linked
+ * first in an i80960 executable. It contains the true entry point;
+ * it performs startup up initialization and then calls 'main'.
+ *
+ * 'sf' is the name of a variable in crtmon960.o that is set
+ * during startup to the address of the first frame.
+ *
+ * 'a' is the address of that variable in 80960 memory.
+ */
+ static char sf[] = "start_frame";
+ CORE_ADDR a;
+
+
+ chain &= ~0x3f; /* Zero low 6 bits because previous frame pointers
+ contain return status info in them. */
+ if ( chain == 0 ){
+ return 0;
+ }
+
+ sym = lookup_symbol(sf, 0, VAR_NAMESPACE, (int *)NULL,
+ (struct symtab **)NULL);
+ if ( sym != 0 ){
+ a = SYMBOL_VALUE (sym);
+ } else {
+ msymbol = lookup_minimal_symbol (sf, NULL, NULL);
+ if (msymbol == NULL)
+ return 0;
+ a = SYMBOL_VALUE_ADDRESS (msymbol);
+ }
+
+ return ( chain != read_memory_integer(a,4) );
+}
+
+void
+_initialize_i960_tdep ()
+{
+ check_host ();
+
+ tm_print_insn = print_insn_i960;
+}