FIXME: Shadow updates in sim/tic80/sim-calls.c */
#define SP_REGNUM 1 /* Contains address of top of stack */
-#define FP_REGNUM 31 /* Contains address of executing stack frame */
+#define ARG0_REGNUM 2 /* Contains argument 1 (r3 has high word) */
+#define RET_REGNUM 2 /* Contains function return value */
+#define ARGLAST_REGNUM 12 /* Contains argument 6 (r13 has high word) */
+#define FP_REGNUM 30 /* Contains address of executing stack frame */
+#define LR_REGNUM 31 /* Contains address of caller (link register) */
#define PC_REGNUM 32 /* Contains program counter (FIXME?) */
#define NPC_REGNUM 33 /* Contains the next program counter (FIXME?) */
#define A0_REGNUM 34 /* Accumulator register 0 */
#define DECR_PC_AFTER_BREAK 0 /* FIXME! */
-/* Push an empty stack frame, to record the current PC, etc. */
-
-#define PUSH_DUMMY_FRAME tic80_push_dummy_frame()
-extern void tic80_push_dummy_frame PARAMS ((void));
-
/* Discard from the stack the innermost frame, restoring all registers. */
-#define POP_FRAME tic80_pop_frame()
-extern void tic80_pop_frame PARAMS ((void));
+#define POP_FRAME tic80_pop_frame(get_current_frame ())
+extern struct frame_info *tic80_pop_frame PARAMS ((struct frame_info *frame));
/* Return number of bytes at start of arglist that are not really args. */
#define FRAME_ARGS_ADDRESS(fi) (fi)->frame
#define FRAME_LOCALS_ADDRESS(fi) (fi)->frame
+/* Define other aspects of the stack frame.
+ We keep the offsets of all saved registers, 'cause we need 'em a lot!
+ We also keep the current size of the stack frame, and the offset of
+ the frame pointer from the stack pointer (for frameless functions, and
+ when we're still in the prologue of a function with a frame) */
+
+#define EXTRA_FRAME_INFO \
+ struct frame_saved_regs fsr; \
+ int framesize; \
+ int frameoffset; \
+ int framereg;
+
+extern void tic80_init_extra_frame_info PARAMS ((struct frame_info *fi));
+#define INIT_EXTRA_FRAME_INFO(fromleaf, fi) tic80_init_extra_frame_info (fi)
+#define INIT_FRAME_PC /* Not necessary */
+
/* 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
the new frame is not set up until the new function executes
some instructions. */
-#define SAVED_PC_AFTER_CALL(frame) tic80_saved_pc_after_call(frame)
-extern CORE_ADDR tic80_saved_pc_after_call PARAMS ((struct frame_info *));
+#define SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM)
/* Describe the pointer in each stack frame to the previous stack frame
(its caller). */
#define FRAME_SAVED_PC(FRAME) tic80_frame_saved_pc (FRAME)
extern CORE_ADDR tic80_frame_saved_pc PARAMS ((struct frame_info *));
+/* Store the address of the place in which to copy the structure the
+ subroutine will return. This is called from call_function.
+
+ We store structs through a pointer passed in R2 */
+
+#define STORE_STRUCT_RETURN(STRUCT_ADDR, SP) \
+ write_register (ARG0_REGNUM, STRUCT_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) \
- tic80_extract_return_value((TYPE), (REGBUF), (VALBUF))
-extern void tic80_extract_return_value PARAMS ((struct type *, char *, char *));
+ memcpy ((VALBUF), \
+ (char *)(REGBUF) + REGISTER_BYTE (RET_REGNUM) + \
+ ((TYPE_LENGTH (TYPE) > 4 ? 8 : 4) - TYPE_LENGTH (TYPE)), \
+ TYPE_LENGTH (TYPE))
/* Write into appropriate registers a function return value
of type TYPE, given in virtual format. */
#define STORE_RETURN_VALUE(TYPE,VALBUF) \
- tic80_store_return_value((TYPE), (VALBUF))
-extern void tic80_store_return_value PARAMS ((struct type *, char *));
+ write_register_bytes(REGISTER_BYTE (RET_REGNUM) + \
+ ((TYPE_LENGTH (TYPE) > 4 ? 8:4) - TYPE_LENGTH (TYPE)),\
+ (VALBUF), TYPE_LENGTH (TYPE));
+
+
+
+/* PUSH_ARGUMENTS */
+extern CORE_ADDR tic80_push_arguments PARAMS ((int nargs,
+ struct value **args,
+ CORE_ADDR sp,
+ unsigned char struct_return,
+ CORE_ADDR struct_addr));
+
+#define PUSH_ARGUMENTS(NARGS, ARGS, SP, STRUCT_RETURN, STRUCT_ADDR) \
+ (SP) = tic80_push_arguments (NARGS, ARGS, SP, STRUCT_RETURN, STRUCT_ADDR)
+
+/* PUSH_RETURN_ADDRESS */
+extern CORE_ADDR tic80_push_return_address PARAMS ((CORE_ADDR, CORE_ADDR));
+#define PUSH_RETURN_ADDRESS(PC, SP) tic80_push_return_address (PC, SP)
+
+/* override the standard get_saved_register function with
+ one that takes account of generic CALL_DUMMY frames */
+#define GET_SAVED_REGISTER
+
+#define USE_GENERIC_DUMMY_FRAMES
+#define CALL_DUMMY {0}
+#define CALL_DUMMY_LENGTH (0)
+#define CALL_DUMMY_START_OFFSET (0)
+#define CALL_DUMMY_BREAKPOINT_OFFSET (0)
+#define FIX_CALL_DUMMY(DUMMY1, STARTADDR, FUNADDR, NARGS, ARGS, TYPE, GCCP)
+#define CALL_DUMMY_LOCATION AT_ENTRY_POINT
+#define CALL_DUMMY_ADDRESS() entry_point_address ()
+
+/* generic dummy frame stuff */
+
+#define PUSH_DUMMY_FRAME generic_push_dummy_frame ()
+#define PC_IN_CALL_DUMMY(PC, SP, FP) generic_pc_in_call_dummy (PC, SP)
#endif /* TM_TIC80_H */
-/* Target-dependent code for the TI TMS320C80 (MVP) architecture,
- for GDB, the GNU Debugger.
- Copyright 1997 Free Software Foundation, Inc.
+/* Target-dependent code for the TI TMS320C80 (MVP) for GDB, the GNU debugger.
+ Copyright 1996, Free Software Foundation, Inc.
This file is part of GDB.
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "defs.h"
+#include "value.h"
+#include "frame.h"
+#include "inferior.h"
+#include "obstack.h"
+#include "target.h"
+#include "bfd.h"
+#include "gdb_string.h"
+#include "gdbcore.h"
+#include "symfile.h"
+
+/* Function: frame_find_saved_regs
+ Return the frame_saved_regs structure for the frame.
+ Doesn't really work for dummy frames, but it does pass back
+ an empty frame_saved_regs, so I guess that's better than total failure */
+
+void
+tic80_frame_find_saved_regs (fi, regaddr)
+ struct frame_info *fi;
+ struct frame_saved_regs *regaddr;
+{
+ memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs));
+}
+
+/* Function: skip_prologue
+ Find end of function prologue. */
CORE_ADDR
tic80_skip_prologue (pc)
CORE_ADDR pc;
{
- error ("tic80_skip_prologue not implemented");
+ CORE_ADDR func_addr, func_end;
+ struct symtab_and_line sal;
+
+ /* See what the symbol table says */
+
+ if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
+ {
+ sal = find_pc_line (func_addr, 0);
+
+ if (sal.line != 0 && sal.end < func_end)
+ return sal.end;
+ else
+ /* Either there's no line info, or the line after the prologue is after
+ the end of the function. In this case, there probably isn't a
+ prologue. */
+ return pc;
+ }
+
+ /* We can't find the start of this function, so there's nothing we can do. */
+ return pc;
+}
+
+/* Function: tic80_scan_prologue
+ This function decodes the target function prologue to determine:
+ 1) the size of the stack frame
+ 2) which registers are saved on it
+ 3) the offsets of saved regs
+ 4) the frame size
+ This information is stored in the "extra" fields of the frame_info. */
+
+static void
+tic80_scan_prologue (fi)
+ struct frame_info *fi;
+{
+ struct symtab_and_line sal;
+ CORE_ADDR prologue_start, prologue_end, current_pc;
+
+ /* Assume there is no frame until proven otherwise. */
+ fi->framereg = SP_REGNUM;
+ fi->framesize = 0;
+ fi->frameoffset = 0;
+
+ /* this code essentially duplicates skip_prologue,
+ but we need the start address below. */
+
+ if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
+ {
+ sal = find_pc_line (prologue_start, 0);
+
+ if (sal.line == 0) /* no line info, use current PC */
+ if (prologue_start != entry_point_address ())
+ prologue_end = fi->pc;
+ else
+ return; /* _start has no frame or prologue */
+ else if (sal.end < prologue_end) /* next line begins after fn end */
+ prologue_end = sal.end; /* (probably means no prologue) */
+ }
+ else
+/* FIXME */
+ prologue_end = prologue_start + 40; /* We're in the boondocks: allow for */
+ /* 16 pushes, an add, and "mv fp,sp" */
+
+ prologue_end = min (prologue_end, fi->pc);
+
+ /* Now search the prologue looking for instructions that set up the
+ frame pointer, adjust the stack pointer, and save registers. */
+
+ for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 4)
+ {
+ unsigned int insn;
+ int regno;
+ int offset = 0;
+
+ insn = read_memory_unsigned_integer (current_pc, 4);
+
+ if ((insn & 0x301000) == 0x301000) /* Long immediate? */
+/* FIXME - set offset for long immediate instructions */
+ current_pc += 4;
+ else
+ {
+ offset = insn & 0x7fff; /* extract 15-bit offset */
+ if (offset & 0x4000) /* if negative, sign-extend */
+ offset = -(0x8000 - offset);
+ }
+
+ if ((insn & 0x7fd0000) == 0x590000) /* st.{w,d} reg, xx(r1) */
+ {
+ regno = ((insn >> 27) & 0x1f);
+ fi->fsr.regs[regno] = offset;
+ if (insn & 0x8000) /* 64-bit store (st.d)? */
+ fi->fsr.regs[regno+1] = offset+4;
+ }
+ else if ((insn & 0xffff8000) == 0x086c8000) /* addu xx, r1, r1 */
+ fi->framesize = -offset;
+ else if ((insn & 0xffff8000) == 0xf06c8000) /* addu xx, r1, r30 */
+ {
+ fi->framereg = FP_REGNUM; /* fp is now valid */
+ fi->frameoffset = offset;
+ break; /* end of stack adjustments */
+ }
+ else if (insn == 0xf03b2001) /* addu r1, r0, r30 */
+ {
+ fi->framereg = FP_REGNUM; /* fp is now valid */
+ fi->frameoffset = 0;
+ break; /* end of stack adjustments */
+ }
+ else
+/* FIXME - handle long immediate instructions */
+ break; /* anything else isn't prologue */
+ }
+}
+
+/* Function: init_extra_frame_info
+ This function actually figures out the frame address for a given pc and
+ sp. This is tricky on the c80 because we sometimes don't use an explicit
+ frame pointer, and the previous stack pointer isn't necessarily recorded
+ on the stack. The only reliable way to get this info is to
+ examine the prologue. */
+
+void
+tic80_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;
+ }
+ else
+ {
+ tic80_scan_prologue (fi);
+
+ if (!fi->next) /* this is the innermost frame? */
+ fi->frame = read_register (fi->framereg);
+ else /* not the innermost frame */
+ if (fi->framereg == FP_REGNUM) /* we have an FP */
+ if (fi->next->fsr.regs[FP_REGNUM] != 0) /* caller saved our FP */
+ fi->frame = read_memory_integer (fi->next->fsr.regs[FP_REGNUM], 4);
+ for (reg = 0; reg < NUM_REGS; reg++)
+ if (fi->fsr.regs[reg] != 0)
+ fi->fsr.regs[reg] += fi->frame - 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
+tic80_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_integer (fi->fsr.regs[regnum],
+ REGISTER_RAW_SIZE(regnum));
+ return read_register (regnum);
}
+/* Function: frame_chain
+ Given a GDB frame, determine the address of the calling function's frame.
+ This will be used to create a new GDB frame struct, and then
+ INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
+ For c80, we save the frame size when we initialize the frame_info. */
+
CORE_ADDR
-tic80_frame_chain (finfo)
- struct frame_info *finfo;
+tic80_frame_chain (fi)
+ struct frame_info *fi;
{
- error ("tic80_frame_chain not implemented");
+ CORE_ADDR fn_start, callers_pc, fp;
+
+ /* 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 = tic80_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 */
+
+ if (fi->framereg == FP_REGNUM)
+ return tic80_find_callers_reg (fi, FP_REGNUM);
+ else
+ return fi->frame + fi->framesize;
}
+/* Function: pop_frame
+ Discard from the stack the innermost frame,
+ restoring all saved registers. */
+
+struct frame_info *
+tic80_pop_frame (frame)
+ struct frame_info *frame;
+{
+ int regnum;
+
+ if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
+ generic_pop_dummy_frame ();
+ else
+ {
+ for (regnum = 0; regnum < NUM_REGS; regnum++)
+ if (frame->fsr.regs[regnum] != 0)
+ write_register (regnum,
+ read_memory_integer (frame->fsr.regs[regnum], 4));
+
+ write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
+ write_register (SP_REGNUM, read_register (FP_REGNUM));
+#if 0
+ if (read_register (PSW_REGNUM) & 0x80)
+ write_register (SPU_REGNUM, read_register (SP_REGNUM));
+ else
+ write_register (SPI_REGNUM, read_register (SP_REGNUM));
+#endif
+ }
+ flush_cached_frames ();
+ return NULL;
+}
+
+/* Function: frame_saved_pc
+ Find the caller of this frame. We do this by seeing if LR_REGNUM is saved
+ in the stack anywhere, otherwise we get it from the registers. */
+
CORE_ADDR
-tic80_frame_saved_pc (finfo)
- struct frame_info *finfo;
+tic80_frame_saved_pc (fi)
+ struct frame_info *fi;
{
- error ("tic80_frame_saved_pc not implemented");
+ if (PC_IN_CALL_DUMMY(fi->pc, fi->frame, fi->frame))
+ return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM);
+ else
+ return tic80_find_callers_reg (fi, LR_REGNUM);
}
+/* Function: tic80_push_return_address (pc, sp)
+ Set up the return address for the inferior function call.
+ Necessary for targets that don't actually execute a JSR/BSR instruction
+ (ie. when using an empty CALL_DUMMY) */
+
CORE_ADDR
-tic80_saved_pc_after_call (finfo)
- struct frame_info *finfo;
+tic80_push_return_address (pc, sp)
+ CORE_ADDR pc;
+ CORE_ADDR sp;
{
- error ("tic80_saved_pc_after_call not implemented");
+ write_register (LR_REGNUM, CALL_DUMMY_ADDRESS ());
+ return sp;
}
-void
-tic80_pop_frame ()
+
+/* Function: push_arguments
+ Setup the function arguments for calling a function in the inferior.
+
+ On the TI C80 architecture, there are six register pairs (R2/R3 to R12/13)
+ which are dedicated for passing function arguments. Up to the first six
+ arguments (depending on size) may go into these registers.
+ The rest go on the stack.
+
+ Arguments that are smaller than 4 bytes will still take up a whole
+ register or a whole 32-bit word on the stack, and will be
+ right-justified in the register or the stack word. This includes
+ chars, shorts, and small aggregate types.
+
+ Arguments that are four bytes or less in size are placed in the
+ even-numbered register of a register pair, and the odd-numbered
+ register is not used.
+
+ Arguments of 8 bytes size (such as floating point doubles) are placed
+ in a register pair. The least significant 32-bit word is placed in
+ the even-numbered register, and the most significant word in the
+ odd-numbered register.
+
+ Aggregate types with sizes between 4 and 8 bytes are passed
+ entirely on the stack, and are left-justified within the
+ double-word (as opposed to aggregates smaller than 4 bytes
+ which are right-justified).
+
+ Aggregates of greater than 8 bytes are first copied onto the stack,
+ and then a pointer to the copy is passed in the place of the normal
+ argument (either in a register if available, or on the stack).
+
+ Functions that must return an aggregate type can return it in the
+ normal return value registers (R2 and R3) if its size is 8 bytes or
+ less. For larger return values, the caller must allocate space for
+ the callee to copy the return value to. A pointer to this space is
+ passed as an implicit first argument, always in R0. */
+
+CORE_ADDR
+tic80_push_arguments (nargs, args, sp, struct_return, struct_addr)
+ int nargs;
+ value_ptr *args;
+ CORE_ADDR sp;
+ unsigned char struct_return;
+ CORE_ADDR struct_addr;
{
- error ("tic80_pop_frame not implemented");
+ int stack_offset, stack_alloc;
+ int argreg;
+ int argnum;
+ struct type *type;
+ CORE_ADDR regval;
+ char *val;
+ char valbuf[4];
+ int len;
+ int odd_sized_struct;
+
+ /* first force sp to a 4-byte alignment */
+ sp = sp & ~3;
+
+ argreg = ARG0_REGNUM;
+ /* The "struct return pointer" pseudo-argument goes in R0 */
+ if (struct_return)
+ write_register (argreg++, struct_addr);
+
+ /* Now make sure there's space on the stack */
+ for (argnum = 0, stack_alloc = 0;
+ argnum < nargs; argnum++)
+ stack_alloc += ((TYPE_LENGTH(VALUE_TYPE(args[argnum])) + 3) & ~3);
+ sp -= stack_alloc; /* make room on stack for args */
+
+
+ /* Now load as many as possible of the first arguments into
+ registers, and push the rest onto the stack. There are 16 bytes
+ in four registers available. Loop thru args from first to last. */
+
+ argreg = ARG0_REGNUM;
+ for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++)
+ {
+ type = VALUE_TYPE (args[argnum]);
+ len = TYPE_LENGTH (type);
+ memset(valbuf, 0, sizeof(valbuf));
+ val = (char *) VALUE_CONTENTS (args[argnum]);
+ if (len < 4)
+ { /* value gets right-justified in the register or stack word */
+ memcpy(valbuf + (4 - len), val, len);
+ val = valbuf;
+ }
+
+/* FIXME -- tic80 can take doubleword arguments in register pairs */
+ if (len > 4 && (len & 3) != 0)
+ odd_sized_struct = 1; /* such structs go entirely on stack */
+ else
+ odd_sized_struct = 0;
+ while (len > 0)
+ {
+ if (argreg > ARGLAST_REGNUM || odd_sized_struct)
+ { /* must go on the stack */
+ write_memory (sp + stack_offset, val, 4);
+ stack_offset += 4;
+ }
+ /* NOTE WELL!!!!! This is not an "else if" clause!!!
+ That's because some *&^%$ things get passed on the stack
+ AND in the registers! */
+ if (argreg <= ARGLAST_REGNUM)
+ { /* there's room in a register */
+ regval = extract_address (val, REGISTER_RAW_SIZE(argreg));
+ write_register (argreg, regval);
+ argreg += 2; /* FIXME -- what about doubleword args? */
+ }
+ /* Store the value 4 bytes at a time. This means that things
+ larger than 4 bytes may go partly in registers and partly
+ on the stack. */
+ len -= REGISTER_RAW_SIZE(argreg);
+ val += REGISTER_RAW_SIZE(argreg);
+ }
+ }
+ return sp;
}
+/* Function: get_saved_register
+ Just call the generic_get_saved_register function. */
+
void
-tic80_store_return_value (valtype, valbuf)
- struct type *valtype;
- char *valbuf;
+get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval)
+ char *raw_buffer;
+ int *optimized;
+ CORE_ADDR *addrp;
+ struct frame_info *frame;
+ int regnum;
+ enum lval_type *lval;
{
- error ("tic80_store_return_value not implemented");
+ generic_get_saved_register (raw_buffer, optimized, addrp,
+ frame, regnum, lval);
}
-/* 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. */
+/* Function: tic80_write_sp
+ Because SP is really a read-only register that mirrors either SPU or SPI,
+ we must actually write one of those two as well, depending on PSW. */
void
-tic80_frame_find_saved_regs (fi, fsr)
- struct frame_info *fi;
- struct frame_saved_regs *fsr;
+tic80_write_sp (val)
+ CORE_ADDR val;
{
- error ("tic80_frame_find_saved_regs not implemented");
-}
+#if 0
+ unsigned long psw = read_register (PSW_REGNUM);
-/* Given a return value in `regbuf' with a type `valtype',
- extract and copy its value into `valbuf'. */
+ if (psw & 0x80) /* stack mode: user or interrupt */
+ write_register (SPU_REGNUM, val);
+ else
+ write_register (SPI_REGNUM, val);
+#endif
+ write_register (SP_REGNUM, val);
+}
void
-tic80_extract_return_value (valtype, regbuf, valbuf)
- struct type *valtype;
- char regbuf[REGISTER_BYTES];
- char *valbuf;
+_initialize_tic80_tdep ()
{
- error ("tic80_extract_return_value not implemented");
+ tm_print_insn = print_insn_tic80;
}
+
projects / binutils-gdb.git / commitdiff