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+/* Target-dependent code for the Fujitsu FR30.
+ Copyright 1999, Free Software Foundation, Inc.
+
+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 "frame.h"
+#include "inferior.h"
+#include "obstack.h"
+#include "target.h"
+#include "value.h"
+#include "bfd.h"
+#include "gdb_string.h"
+#include "gdbcore.h"
+#include "symfile.h"
+
+/* Function: pop_frame
+ This routine gets called when either the user uses the `return'
+ command, or the call dummy breakpoint gets hit. */
+
+void
+fr30_pop_frame ()
+{
+ struct frame_info *frame = get_current_frame();
+ int regnum;
+ CORE_ADDR sp = read_register(SP_REGNUM);
+
+ if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame))
+ generic_pop_dummy_frame ();
+ else
+ {
+ write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
+
+ for (regnum = 0; regnum < NUM_REGS; regnum++)
+ if (frame->fsr.regs[regnum] != 0) {
+ write_register (regnum,
+ read_memory_unsigned_integer (frame->fsr.regs[regnum],
+ REGISTER_RAW_SIZE(regnum)));
+ }
+ write_register (SP_REGNUM, sp + frame->framesize);
+ }
+ flush_cached_frames ();
+}
+
+/* Function: skip_prologue
+ Return the address of the first code past the prologue of the function. */
+
+CORE_ADDR
+fr30_skip_prologue(CORE_ADDR pc)
+{
+ CORE_ADDR func_addr, func_end;
+
+ /* See what the symbol table says */
+
+ if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
+ {
+ struct symtab_and_line sal;
+
+ sal = find_pc_line (func_addr, 0);
+
+ if (sal.line != 0 && sal.end < func_end) {
+ return sal.end;
+ }
+ }
+
+/* Either we didn't find the start of this function (nothing we can do),
+ or there's no line info, or the line after the prologue is after
+ the end of the function (there probably isn't a prologue). */
+
+ return pc;
+}
+
+
+/* Function: push_arguments
+ Setup arguments and RP for a call to the target. First four args
+ go in FIRST_ARGREG -> LAST_ARGREG, subsequent args go on stack...
+ Structs are passed by reference. XXX not right now Z.R.
+ 64 bit quantities (doubles and long longs) may be split between
+ the regs and the stack.
+ When calling a function that returns a struct, a pointer to the struct
+ is passed in as a secret first argument (always in FIRST_ARGREG).
+
+ Stack space for the args has NOT been allocated: that job is up to us.
+*/
+
+CORE_ADDR
+fr30_push_arguments(nargs, args, sp, struct_return, struct_addr)
+ int nargs;
+ value_ptr * args;
+ CORE_ADDR sp;
+ int struct_return;
+ CORE_ADDR struct_addr;
+{
+ int argreg;
+ int argnum;
+ int stack_offset;
+ struct stack_arg {
+ char *val;
+ int len;
+ int offset;
+ };
+ struct stack_arg *stack_args =
+ (struct stack_arg*)alloca (nargs * sizeof (struct stack_arg));
+ int nstack_args = 0;
+
+ argreg = FIRST_ARGREG;
+
+ /* the struct_return pointer occupies the first parameter-passing reg */
+ if (struct_return)
+ write_register (argreg++, struct_addr);
+
+ stack_offset = 0;
+
+ /* Process args from left to right. Store as many as allowed in
+ registers, save the rest to be pushed on the stack */
+ for(argnum = 0; argnum < nargs; argnum++)
+ {
+ char * val;
+ value_ptr arg = args[argnum];
+ struct type * arg_type = check_typedef (VALUE_TYPE (arg));
+ struct type * target_type = TYPE_TARGET_TYPE (arg_type);
+ int len = TYPE_LENGTH (arg_type);
+ enum type_code typecode = TYPE_CODE (arg_type);
+ CORE_ADDR regval;
+ int newarg;
+
+ val = (char *) VALUE_CONTENTS (arg);
+
+ {
+ /* Copy the argument to general registers or the stack in
+ register-sized pieces. Large arguments are split between
+ registers and stack. */
+ while (len > 0)
+ {
+ if (argreg <= LAST_ARGREG)
+ {
+ int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE;
+ regval = extract_address (val, partial_len);
+
+ /* It's a simple argument being passed in a general
+ register. */
+ write_register (argreg, regval);
+ argreg++;
+ len -= partial_len;
+ val += partial_len;
+ }
+ else
+ {
+ /* keep for later pushing */
+ stack_args[nstack_args].val = val;
+ stack_args[nstack_args++].len = len;
+ break;
+ }
+ }
+ }
+ }
+ /* now do the real stack pushing, process args right to left */
+ while(nstack_args--)
+ {
+ sp -= stack_args[nstack_args].len;
+ write_memory(sp, stack_args[nstack_args].val,
+ stack_args[nstack_args].len);
+ }
+
+ /* Return adjusted stack pointer. */
+ return sp;
+}
+
+_initialize_fr30_tdep()
+{
+ extern int print_insn_fr30(bfd_vma, disassemble_info *);
+
+ tm_print_insn = print_insn_fr30;
+}
+
+/* Function: check_prologue_cache
+ Check if prologue for this frame's PC has already been scanned.
+ If it has, copy the relevant information about that prologue and
+ return non-zero. Otherwise do not copy anything and return zero.
+
+ The information saved in the cache includes:
+ * the frame register number;
+ * the size of the stack frame;
+ * the offsets of saved regs (relative to the old SP); and
+ * the offset from the stack pointer to the frame pointer
+
+ The cache contains only one entry, since this is adequate
+ for the typical sequence of prologue scan requests we get.
+ When performing a backtrace, GDB will usually ask to scan
+ the same function twice in a row (once to get the frame chain,
+ and once to fill in the extra frame information).
+*/
+
+static struct frame_info prologue_cache;
+
+static int
+check_prologue_cache (fi)
+ struct frame_info * fi;
+{
+ int i;
+
+ if (fi->pc == prologue_cache.pc)
+ {
+ fi->framereg = prologue_cache.framereg;
+ fi->framesize = prologue_cache.framesize;
+ fi->frameoffset = prologue_cache.frameoffset;
+ for (i = 0; i <= NUM_REGS; i++)
+ fi->fsr.regs[i] = prologue_cache.fsr.regs[i];
+ return 1;
+ }
+ else
+ return 0;
+}
+
+
+/* Function: save_prologue_cache
+ Copy the prologue information from fi to the prologue cache.
+*/
+
+static void
+save_prologue_cache (fi)
+ struct frame_info * fi;
+{
+ int i;
+
+ prologue_cache.pc = fi->pc;
+ prologue_cache.framereg = fi->framereg;
+ prologue_cache.framesize = fi->framesize;
+ prologue_cache.frameoffset = fi->frameoffset;
+
+ for (i = 0; i <= NUM_REGS; i++) {
+ prologue_cache.fsr.regs[i] = fi->fsr.regs[i];
+ }
+}
+
+
+/* Function: scan_prologue
+ Scan the prologue of the function that contains PC, and record what
+ we find in PI. PI->fsr must be zeroed by the called. Returns the
+ pc after the prologue. Note that the addresses saved in pi->fsr
+ are actually just frame relative (negative offsets from the frame
+ pointer). This is because we don't know the actual value of the
+ frame pointer yet. In some circumstances, the frame pointer can't
+ be determined till after we have scanned the prologue. */
+
+static void
+fr30_scan_prologue (fi)
+ struct frame_info * fi;
+{
+ int sp_offset, fp_offset;
+ CORE_ADDR prologue_start, prologue_end, current_pc;
+
+ /* Check if this function is already in the cache of frame information. */
+ if (check_prologue_cache (fi))
+ return;
+
+ /* Assume there is no frame until proven otherwise. */
+ fi->framereg = SP_REGNUM;
+ fi->framesize = 0;
+ fi->frameoffset = 0;
+
+ /* Find the function prologue. If we can't find the function in
+ the symbol table, peek in the stack frame to find the PC. */
+ if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
+ {
+ /* Assume the prologue is everything between the first instruction
+ in the function and the first source line. */
+ struct symtab_and_line sal = find_pc_line (prologue_start, 0);
+
+ if (sal.line == 0) /* no line info, use current PC */
+ prologue_end = fi->pc;
+ else if (sal.end < prologue_end) /* next line begins after fn end */
+ prologue_end = sal.end; /* (probably means no prologue) */
+ }
+ else
+ {
+ /* XXX Z.R. What now??? The following is entirely bogus */
+ prologue_start = (read_memory_integer (fi->frame, 4) & 0x03fffffc) - 12;
+ prologue_end = prologue_start + 40;
+ }
+
+ /* Now search the prologue looking for instructions that set up the
+ frame pointer, adjust the stack pointer, and save registers. */
+
+ sp_offset = fp_offset = 0;
+ for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2)
+ {
+ unsigned int insn;
+
+ insn = read_memory_unsigned_integer (current_pc, 2);
+
+ if ((insn & 0xfe00) == 0x8e00) /* stm0 or stm1 */
+ {
+ int reg, mask = insn & 0xff;
+
+ /* scan in one sweep - create virtual 16-bit mask from either insn's mask */
+ if((insn & 0x0100) == 0)
+ {
+ mask <<= 8; /* stm0 - move to upper byte in virtual mask */
+ }
+
+ /* Calculate offsets of saved registers (to be turned later into addresses). */
+ for (reg = R4_REGNUM; reg <= R11_REGNUM; reg++)
+ if (mask & (1 << (15 - reg)))
+ {
+ sp_offset -= 4;
+ fi->fsr.regs[reg] = sp_offset;
+ }
+ }
+ else if((insn & 0xfff0) == 0x1700) /* st rx,@-r15 */
+ {
+ int reg = insn & 0xf;
+
+ sp_offset -= 4;
+ fi->fsr.regs[reg] = sp_offset;
+ }
+ else if((insn & 0xff00) == 0x0f00) /* enter */
+ {
+ fp_offset = fi->fsr.regs[FP_REGNUM] = sp_offset - 4;
+ sp_offset -= 4 * (insn & 0xff);
+ fi->framereg = FP_REGNUM;
+ }
+ else if(insn == 0x1781) /* st rp,@-sp */
+ {
+ sp_offset -= 4;
+ fi->fsr.regs[RP_REGNUM] = sp_offset;
+ }
+ else if(insn == 0x170e) /* st fp,@-sp */
+ {
+ sp_offset -= 4;
+ fi->fsr.regs[FP_REGNUM] = sp_offset;
+ }
+ else if(insn == 0x8bfe) /* mov sp,fp */
+ {
+ fi->framereg = FP_REGNUM;
+ }
+ else if((insn & 0xff00) == 0xa300) /* addsp xx */
+ {
+ sp_offset += 4 * (signed char)(insn & 0xff);
+ }
+ else if((insn & 0xff0f) == 0x9b00 && /* ldi:20 xx,r0 */
+ read_memory_unsigned_integer(current_pc+4, 2)
+ == 0xac0f) /* sub r0,sp */
+ {
+ /* large stack adjustment */
+ sp_offset -= (((insn & 0xf0) << 12) | read_memory_unsigned_integer(current_pc+2, 2));
+ current_pc += 4;
+ }
+ else if(insn == 0x9f80 && /* ldi:32 xx,r0 */
+ read_memory_unsigned_integer(current_pc+6, 2)
+ == 0xac0f) /* sub r0,sp */
+ {
+ /* large stack adjustment */
+ sp_offset -=
+ (read_memory_unsigned_integer(current_pc+2, 2) << 16 |
+ read_memory_unsigned_integer(current_pc+4, 2));
+ current_pc += 6;
+ }
+ }
+
+ /* The frame size is just the negative of the offset (from the original SP)
+ of the last thing thing we pushed on the stack. The frame offset is
+ [new FP] - [new SP]. */
+ fi->framesize = -sp_offset;
+ fi->frameoffset = fp_offset - sp_offset;
+
+ save_prologue_cache (fi);
+}
+
+/* Function: init_extra_frame_info
+ Setup the frame's frame pointer, pc, and frame addresses for saved
+ registers. Most of the work is done in scan_prologue().
+
+ Note that when we are called for the last frame (currently active frame),
+ that fi->pc and fi->frame will already be setup. However, fi->frame will
+ be valid only if this routine uses FP. For previous frames, fi-frame will
+ always be correct (since that is derived from fr30_frame_chain ()).
+
+ We can be called with the PC in the call dummy under two circumstances.
+ First, during normal backtracing, second, while figuring out the frame
+ pointer just prior to calling the target function (see run_stack_dummy). */
+
+void
+fr30_init_extra_frame_info (fi)
+ struct frame_info * fi;
+{
+ int reg;
+
+ if (fi->next)
+ fi->pc = FRAME_SAVED_PC (fi->next);
+
+ memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);
+
+ if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+ {
+ /* We need to setup fi->frame here because run_stack_dummy gets it wrong
+ by assuming it's always FP. */
+ fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM);
+ fi->framesize = 0;
+ fi->frameoffset = 0;
+ return;
+ }
+ fr30_scan_prologue (fi);
+
+ if (!fi->next) /* this is the innermost frame? */
+ fi->frame = read_register (fi->framereg);
+ else /* not the innermost frame */
+ /* If we have an FP, the callee saved it. */
+ if (fi->framereg == FP_REGNUM)
+ if (fi->next->fsr.regs[fi->framereg] != 0)
+ fi->frame = read_memory_integer (fi->next->fsr.regs[fi->framereg],
+ 4);
+ /* Calculate actual addresses of saved registers using offsets determined
+ by fr30_scan_prologue. */
+ for (reg = 0; reg < NUM_REGS; reg++)
+ if (fi->fsr.regs[reg] != 0) {
+ fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->frameoffset;
+ }
+}
+
+/* Function: find_callers_reg
+ Find REGNUM on the stack. Otherwise, it's in an active register.
+ One thing we might want to do here is to check REGNUM against the
+ clobber mask, and somehow flag it as invalid if it isn't saved on
+ the stack somewhere. This would provide a graceful failure mode
+ when trying to get the value of caller-saves registers for an inner
+ frame. */
+
+CORE_ADDR
+fr30_find_callers_reg (fi, regnum)
+ struct frame_info *fi;
+ int regnum;
+{
+ for (; fi; fi = fi->next)
+ if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+ return generic_read_register_dummy (fi->pc, fi->frame, regnum);
+ else if (fi->fsr.regs[regnum] != 0)
+ return read_memory_unsigned_integer (fi->fsr.regs[regnum],
+ REGISTER_RAW_SIZE(regnum));
+
+ return read_register (regnum);
+}
+
+
+/* Function: frame_chain
+ Figure out the frame prior to FI. Unfortunately, this involves
+ scanning the prologue of the caller, which will also be done
+ shortly by fr30_init_extra_frame_info. For the dummy frame, we
+ just return the stack pointer that was in use at the time the
+ function call was made. */
+
+
+CORE_ADDR
+fr30_frame_chain (fi)
+ struct frame_info * fi;
+{
+ CORE_ADDR fn_start, callers_pc, fp;
+ struct frame_info caller_fi;
+ int framereg;
+
+ /* is this a dummy frame? */
+ if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
+ return fi->frame; /* dummy frame same as caller's frame */
+
+ /* is caller-of-this a dummy frame? */
+ callers_pc = FRAME_SAVED_PC(fi); /* find out who called us: */
+ fp = fr30_find_callers_reg (fi, FP_REGNUM);
+ if (PC_IN_CALL_DUMMY (callers_pc, fp, fp))
+ return fp; /* dummy frame's frame may bear no relation to ours */
+
+ if (find_pc_partial_function (fi->pc, 0, &fn_start, 0))
+ if (fn_start == entry_point_address ())
+ return 0; /* in _start fn, don't chain further */
+
+ framereg = fi->framereg;
+
+ /* If the caller is the startup code, we're at the end of the chain. */
+ if (find_pc_partial_function (callers_pc, 0, &fn_start, 0))
+ if (fn_start == entry_point_address ())
+ return 0;
+
+ memset (& caller_fi, 0, sizeof (caller_fi));
+ caller_fi.pc = callers_pc;
+ fr30_scan_prologue (& caller_fi);
+ framereg = caller_fi.framereg;
+
+ /* If the caller used a frame register, return its value.
+ Otherwise, return the caller's stack pointer. */
+ if (framereg == FP_REGNUM)
+ return fr30_find_callers_reg (fi, framereg);
+ else
+ return fi->frame + fi->framesize;
+}
+
+/* Function: frame_saved_pc
+ Find the caller of this frame. We do this by seeing if RP_REGNUM
+ is saved in the stack anywhere, otherwise we get it from the
+ registers. If the inner frame is a dummy frame, return its PC
+ instead of RP, because that's where "caller" of the dummy-frame
+ will be found. */
+
+CORE_ADDR
+fr30_frame_saved_pc (fi)
+ struct frame_info *fi;
+{
+ if (PC_IN_CALL_DUMMY(fi->pc, fi->frame, fi->frame))
+ return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM);
+ else
+ return fr30_find_callers_reg (fi, RP_REGNUM);
+}
+
+/* Function: fix_call_dummy
+ Pokes the callee function's address into the CALL_DUMMY assembly stub.
+ Assumes that the CALL_DUMMY looks like this:
+ jarl <offset24>, r31
+ trap
+ */
+
+int
+fr30_fix_call_dummy (dummy, sp, fun, nargs, args, type, gcc_p)
+ char *dummy;
+ CORE_ADDR sp;
+ CORE_ADDR fun;
+ int nargs;
+ value_ptr *args;
+ struct type *type;
+ int gcc_p;
+{
+ long offset24;
+
+ offset24 = (long) fun - (long) entry_point_address ();
+ offset24 &= 0x3fffff;
+ offset24 |= 0xff800000; /* jarl <offset24>, r31 */
+
+ store_unsigned_integer ((unsigned int *)&dummy[2], 2, offset24 & 0xffff);
+ store_unsigned_integer ((unsigned int *)&dummy[0], 2, offset24 >> 16);
+ return 0;
+}
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