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[PATCH]: Prologue analysis for 68HC12/68HC11
- To: gdb-patches at sourceware dot cygnus dot com
- Subject: [PATCH]: Prologue analysis for 68HC12/68HC11
- From: Stephane Carrez <Stephane dot Carrez at worldnet dot fr>
- Date: Sat, 02 Dec 2000 18:56:51 +0100
Hi!
I've added support for function prologue analysis of 68HC12 targets.
Since the 68HC11 analysis was quite hard-coded for it, I re-wrote the whole
thing to support both 68HC11 and 68HC12. The analysis is more generic
and should allow easier changes and updates.
The prologue description is registered in the gdbarch_tdep so the whole thing follows the gdbarch framework.
I've committed this patch.
Stephane
2000-12-03 Stephane Carrez <Stephane.Carrez@worldnet.fr>
* m68hc11-tdep.c (m68hc11_frame_args_address): Fix args address
computation.
(m68hc11_frame_init_saved_regs): Frame pointer is saved only if
the symbol exist.
(m68hc11_analyze_instruction): New function.
(m6811_prologue, m6812_prologue): New prologue description tables.
(m68hc11_guess_from_prologue): Use the above.
(m68hc11_gdbarch_init): Setup gdbarch_tdep for the prologue
descriptions.
Index: m68hc11-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/m68hc11-tdep.c,v
retrieving revision 1.8
diff -p -r1.8 m68hc11-tdep.c
*** m68hc11-tdep.c 2000/11/24 21:24:04 1.8
--- m68hc11-tdep.c 2000/12/02 16:47:53
***************
*** 1,4 ****
! /* Target-dependent code for Motorola 68HC11
Copyright (C) 1999, 2000 Free Software Foundation, Inc.
Contributed by Stephane Carrez, stcarrez@worldnet.fr
--- 1,4 ----
! /* Target-dependent code for Motorola 68HC11 & 68HC12
Copyright (C) 1999, 2000 Free Software Foundation, Inc.
Contributed by Stephane Carrez, stcarrez@worldnet.fr
*************** Foundation, Inc., 59 Temple Place - Suit
*** 77,82 ****
--- 77,83 ----
#define M68HC11_REG_SIZE (2)
+ struct insn_sequence;
struct gdbarch_tdep
{
/* from the elf header */
*************** struct gdbarch_tdep
*** 87,92 ****
--- 88,96 ----
the address where the last value is saved. For 68hc12, the stack
pointer points to the last value pushed. No offset is necessary. */
int stack_correction;
+
+ /* Description of instructions in the prologue. */
+ struct insn_sequence *prologue;
};
#define M6811_TDEP gdbarch_tdep (current_gdbarch)
*************** m68hc11_frame_saved_pc (struct frame_inf
*** 298,304 ****
static CORE_ADDR
m68hc11_frame_args_address (struct frame_info *frame)
{
! return frame->frame;
}
static CORE_ADDR
--- 302,308 ----
static CORE_ADDR
m68hc11_frame_args_address (struct frame_info *frame)
{
! return frame->frame + frame->extra_info->size + STACK_CORRECTION + 2;
}
static CORE_ADDR
*************** m68hc11_pop_frame (void)
*** 337,342 ****
--- 341,516 ----
flush_cached_frames ();
}
+
+ /* 68HC11 & 68HC12 prologue analysis.
+
+ */
+ #define MAX_CODES 12
+
+ /* 68HC11 opcodes. */
+ #undef M6811_OP_PAGE2
+ #define M6811_OP_PAGE2 (0x18)
+ #define M6811_OP_LDX (0xde)
+ #define M6811_OP_PSHX (0x3c)
+ #define M6811_OP_STS (0x9f)
+ #define M6811_OP_TSX (0x30)
+ #define M6811_OP_XGDX (0x8f)
+ #define M6811_OP_ADDD (0xc3)
+ #define M6811_OP_TXS (0x35)
+ #define M6811_OP_DES (0x34)
+
+ /* 68HC12 opcodes. */
+ #define M6812_OP_PAGE2 (0x18)
+ #define M6812_OP_MOVW (0x01)
+ #define M6812_PB_PSHW (0xae)
+ #define M6812_OP_STS (0x7f)
+ #define M6812_OP_LEAS (0x1b)
+
+ /* Operand extraction. */
+ #define OP_DIRECT (0x100) /* 8-byte direct addressing. */
+ #define OP_IMM_LOW (0x200) /* Low part of 16-bit constant/address. */
+ #define OP_IMM_HIGH (0x300) /* High part of 16-bit constant/address. */
+ #define OP_PBYTE (0x400) /* 68HC12 indexed operand. */
+
+ /* Identification of the sequence. */
+ enum m6811_seq_type
+ {
+ P_LAST = 0,
+ P_SAVE_REG, /* Save a register on the stack. */
+ P_SET_FRAME, /* Setup the frame pointer. */
+ P_LOCAL_1, /* Allocate 1 byte for locals. */
+ P_LOCAL_2, /* Allocate 2 bytes for locals. */
+ P_LOCAL_N /* Allocate N bytes for locals. */
+ };
+
+ struct insn_sequence {
+ enum m6811_seq_type type;
+ unsigned length;
+ unsigned short code[MAX_CODES];
+ };
+
+ /* Sequence of instructions in the 68HC11 function prologue. */
+ static struct insn_sequence m6811_prologue[] = {
+ /* Sequences to save a soft-register. */
+ { P_SAVE_REG, 3, { M6811_OP_LDX, OP_DIRECT,
+ M6811_OP_PSHX } },
+ { P_SAVE_REG, 5, { M6811_OP_PAGE2, M6811_OP_LDX, OP_DIRECT,
+ M6811_OP_PAGE2, M6811_OP_PSHX } },
+
+ /* Sequences to allocate local variables. */
+ { P_LOCAL_N, 7, { M6811_OP_TSX,
+ M6811_OP_XGDX,
+ M6811_OP_ADDD, OP_IMM_HIGH, OP_IMM_LOW,
+ M6811_OP_XGDX,
+ M6811_OP_TXS } },
+ { P_LOCAL_N, 11, { M6811_OP_PAGE2, M6811_OP_TSX,
+ M6811_OP_PAGE2, M6811_OP_XGDX,
+ M6811_OP_ADDD, OP_IMM_HIGH, OP_IMM_LOW,
+ M6811_OP_PAGE2, M6811_OP_XGDX,
+ M6811_OP_PAGE2, M6811_OP_TXS } },
+ { P_LOCAL_1, 1, { M6811_OP_DES } },
+ { P_LOCAL_2, 1, { M6811_OP_PSHX } },
+ { P_LOCAL_2, 2, { M6811_OP_PAGE2, M6811_OP_PSHX } },
+
+ /* Initialize the frame pointer. */
+ { P_SET_FRAME, 2, { M6811_OP_STS, OP_DIRECT } },
+ { P_LAST, 0, { 0 } }
+ };
+
+
+ /* Sequence of instructions in the 68HC12 function prologue. */
+ static struct insn_sequence m6812_prologue[] = {
+ { P_SAVE_REG, 5, { M6812_OP_PAGE2, M6812_OP_MOVW, M6812_PB_PSHW,
+ OP_IMM_HIGH, OP_IMM_LOW } },
+ { P_SET_FRAME, 3, { M6812_OP_STS, OP_IMM_HIGH, OP_IMM_LOW } },
+ { P_LOCAL_N, 2, { M6812_OP_LEAS, OP_PBYTE } },
+ { P_LAST, 0 }
+ };
+
+
+ /* Analyze the sequence of instructions starting at the given address.
+ Returns a pointer to the sequence when it is recognized and
+ the optional value (constant/address) associated with it.
+ Advance the pc for the next sequence. */
+ static struct insn_sequence *
+ m68hc11_analyze_instruction (struct insn_sequence *seq, CORE_ADDR *pc,
+ CORE_ADDR *val)
+ {
+ unsigned char buffer[MAX_CODES];
+ unsigned bufsize;
+ unsigned j;
+ CORE_ADDR cur_val;
+ short v = 0;
+
+ bufsize = 0;
+ for (; seq->type != P_LAST; seq++)
+ {
+ cur_val = 0;
+ for (j = 0; j < seq->length; j++)
+ {
+ if (bufsize < j + 1)
+ {
+ buffer[bufsize] = read_memory_unsigned_integer (*pc + bufsize,
+ 1);
+ bufsize++;
+ }
+ /* Continue while we match the opcode. */
+ if (seq->code[j] == buffer[j])
+ continue;
+
+ if ((seq->code[j] & 0xf00) == 0)
+ break;
+
+ /* Extract a sequence parameter (address or constant). */
+ switch (seq->code[j])
+ {
+ case OP_DIRECT:
+ cur_val = (CORE_ADDR) buffer[j];
+ break;
+
+ case OP_IMM_HIGH:
+ cur_val = cur_val & 0x0ff;
+ cur_val |= (buffer[j] << 8);
+ break;
+
+ case OP_IMM_LOW:
+ cur_val &= 0x0ff00;
+ cur_val |= buffer[j];
+ break;
+
+ case OP_PBYTE:
+ if ((buffer[j] & 0xE0) == 0x80)
+ {
+ v = buffer[j] & 0x1f;
+ if (v & 0x10)
+ v |= 0xfff0;
+ }
+ else if ((buffer[j] & 0xfe) == 0xf0)
+ {
+ v = read_memory_unsigned_integer (*pc + j + 1, 1);
+ if (buffer[j] & 1)
+ v |= 0xff00;
+ }
+ else if (buffer[j] == 0xf2)
+ {
+ v = read_memory_unsigned_integer (*pc + j + 1, 2);
+ }
+ cur_val = v;
+ break;
+ }
+ }
+
+ /* We have a full match. */
+ if (j == seq->length)
+ {
+ *val = cur_val;
+ *pc = *pc + j;
+ return seq;
+ }
+ }
+ return 0;
+ }
+
/* Analyze the function prologue to find some information
about the function:
- the PC of the first line (for m68hc11_skip_prologue)
*************** m68hc11_guess_from_prologue (CORE_ADDR p
*** 349,361 ****
{
CORE_ADDR save_addr;
CORE_ADDR func_end;
- unsigned char op0, op1, op2;
- int add_sp_mode;
- int sp_adjust = 0;
int size;
int found_frame_point;
int saved_reg;
CORE_ADDR first_pc;
first_pc = get_pc_function_start (pc);
size = 0;
--- 523,534 ----
{
CORE_ADDR save_addr;
CORE_ADDR func_end;
int size;
int found_frame_point;
int saved_reg;
CORE_ADDR first_pc;
+ int done = 0;
+ struct insn_sequence *seq_table;
first_pc = get_pc_function_start (pc);
size = 0;
*************** m68hc11_guess_from_prologue (CORE_ADDR p
*** 367,388 ****
*first_line = pc;
return;
}
-
- #define OP_PAGE2 (0x18)
- #define OP_LDX (0xde)
- #define OP_LDY (0xde)
- #define OP_PSHX (0x3c)
- #define OP_PSHY (0x3c)
- #define OP_STS (0x9f)
- #define OP_TSX (0x30)
- #define OP_TSY (0x30)
- #define OP_XGDX (0x8f)
- #define OP_XGDY (0x8f)
- #define OP_ADDD (0xc3)
- #define OP_TXS (0x35)
- #define OP_TYS (0x35)
- #define OP_DES (0x34)
/* The 68hc11 stack is as follows:
--- 540,548 ----
*first_line = pc;
return;
}
+ seq_table = gdbarch_tdep (current_gdbarch)->prologue;
+
/* The 68hc11 stack is as follows:
*************** m68hc11_guess_from_prologue (CORE_ADDR p
*** 426,594 ****
*/
pc = first_pc;
func_end = pc + 128;
- add_sp_mode = 0;
found_frame_point = 0;
! while (pc + 2 < func_end)
{
! op0 = read_memory_unsigned_integer (pc, 1);
! op1 = read_memory_unsigned_integer (pc + 1, 1);
! op2 = read_memory_unsigned_integer (pc + 2, 1);
! /* ldx *frame */
! if (op0 == OP_LDX && op1 == M68HC11_FP_ADDR)
! {
! pc += 2;
! }
! /* ldy *frame */
! else if (op0 == OP_PAGE2 && op1 == OP_LDY
! && op2 == M68HC11_FP_ADDR)
{
! pc += 3;
! }
!
! /* pshx */
! else if (op0 == OP_PSHX)
! {
! pc += 1;
! size += 2;
}
!
! /* pshy */
! else if (op0 == OP_PAGE2 && op1 == OP_PSHX)
{
- pc += 2;
- size += 2;
- }
-
- /* sts *frame */
- else if (op0 == OP_STS && op1 == M68HC11_FP_ADDR)
- {
found_frame_point = 1;
! pc += 2;
! break;
! }
! else if (op0 == OP_TSX && op1 == OP_XGDX)
! {
! add_sp_mode = 1;
! pc += 2;
}
! /* des to allocate 1 byte on the stack */
! else if (op0 == OP_DES)
{
- pc += 1;
size += 1;
- }
- else if (op0 == OP_PAGE2 && op1 == OP_TSY && op2 == OP_PAGE2)
- {
- op0 = read_memory_unsigned_integer (pc + 3, 1);
- if (op0 != OP_XGDY)
- break;
-
- add_sp_mode = 2;
- pc += 4;
- }
- else if (add_sp_mode && op0 == OP_ADDD)
- {
- sp_adjust = read_memory_unsigned_integer (pc + 1, 2);
- if (sp_adjust & 0x8000)
- sp_adjust |= 0xffff0000L;
-
- sp_adjust = -sp_adjust;
- add_sp_mode |= 4;
- pc += 3;
- }
- else if (add_sp_mode == (1 | 4) && op0 == OP_XGDX
- && op1 == OP_TXS)
- {
- size += sp_adjust;
- pc += 2;
- add_sp_mode = 0;
- }
- else if (add_sp_mode == (2 | 4) && op0 == OP_PAGE2
- && op1 == OP_XGDY && op2 == OP_PAGE2)
- {
- op0 = read_memory_unsigned_integer (pc + 3, 1);
- if (op0 != OP_TYS)
- break;
-
- size += sp_adjust;
- pc += 4;
- add_sp_mode = 0;
}
! else
{
! break;
! }
! }
!
! if (found_frame_point == 0)
! {
! *frame_offset = 0;
! }
! else
! {
! *frame_offset = size;
! }
!
! /* Now, look forward to see how many registers are pushed on the stack.
! We look only for soft registers so there must be a first LDX *REG
! before a PSHX. */
! saved_reg = -1;
! save_addr = fp;
! while (pc + 2 < func_end)
! {
! op0 = read_memory_unsigned_integer (pc, 1);
! op1 = read_memory_unsigned_integer (pc + 1, 1);
! op2 = read_memory_unsigned_integer (pc + 2, 1);
! if (op0 == OP_LDX)
! {
! saved_reg = m68hc11_which_soft_register (op1);
! if (saved_reg < 0 || saved_reg == SOFT_FP_REGNUM)
! break;
!
! pc += 2;
! }
! else if (op0 == OP_PAGE2 && op1 == OP_LDY)
! {
! saved_reg = m68hc11_which_soft_register (op2);
! if (saved_reg < 0 || saved_reg == SOFT_FP_REGNUM)
! break;
!
! pc += 3;
! }
! else if (op0 == OP_PSHX)
! {
! /* If there was no load, this is a push for a function call. */
! if (saved_reg < 0 || saved_reg >= M68HC11_ALL_REGS)
! break;
!
! /* Keep track of the address where that register is saved
! on the stack. */
! save_addr -= 2;
! if (pushed_regs)
! pushed_regs[saved_reg] = save_addr;
!
! pc += 1;
! saved_reg = -1;
! }
! else if (op0 == OP_PAGE2 && op1 == OP_PSHY)
! {
! if (saved_reg < 0 || saved_reg >= M68HC11_ALL_REGS)
! break;
!
! /* Keep track of the address where that register is saved
! on the stack. */
! save_addr -= 2;
! if (pushed_regs)
! pushed_regs[saved_reg] = save_addr;
!
! pc += 2;
! saved_reg = -1;
}
! else
{
! break;
}
}
*first_line = pc;
--- 586,640 ----
*/
pc = first_pc;
func_end = pc + 128;
found_frame_point = 0;
! *frame_offset = 0;
! save_addr = fp;
! while (!done && pc + 2 < func_end)
{
! struct insn_sequence *seq;
! CORE_ADDR val;
! seq = m68hc11_analyze_instruction (seq_table, &pc, &val);
! if (seq == 0)
! break;
! if (seq->type == P_SAVE_REG)
{
! if (found_frame_point)
! {
! saved_reg = m68hc11_which_soft_register (val);
! if (saved_reg < 0)
! break;
!
! save_addr -= 2;
! if (pushed_regs)
! pushed_regs[saved_reg] = save_addr;
! }
! else
! {
! size += 2;
! }
}
! else if (seq->type == P_SET_FRAME)
{
found_frame_point = 1;
! *frame_offset = size;
}
! else if (seq->type == P_LOCAL_1)
{
size += 1;
}
! else if (seq->type == P_LOCAL_2)
{
! size += 2;
}
! else if (seq->type == P_LOCAL_N)
{
! /* Stack pointer is decremented for the allocation. */
! if (val & 0x8000)
! size -= (int) (val) | 0xffff0000;
! else
! size -= val;
}
}
*first_line = pc;
*************** m68hc11_frame_init_saved_regs (struct fr
*** 668,674 ****
fi->saved_regs);
addr = fi->frame + fi->extra_info->size + STACK_CORRECTION;
! fi->saved_regs[SOFT_FP_REGNUM] = addr - 2;
fi->saved_regs[HARD_SP_REGNUM] = addr;
fi->saved_regs[HARD_PC_REGNUM] = fi->saved_regs[HARD_SP_REGNUM];
}
--- 714,721 ----
fi->saved_regs);
addr = fi->frame + fi->extra_info->size + STACK_CORRECTION;
! if (soft_regs[SOFT_FP_REGNUM].name)
! fi->saved_regs[SOFT_FP_REGNUM] = addr - 2;
fi->saved_regs[HARD_SP_REGNUM] = addr;
fi->saved_regs[HARD_PC_REGNUM] = fi->saved_regs[HARD_SP_REGNUM];
}
*************** m68hc11_gdbarch_init (struct gdbarch_inf
*** 1009,1018 ****
--- 1056,1067 ----
{
case bfd_arch_m68hc11:
tdep->stack_correction = 1;
+ tdep->prologue = m6811_prologue;
break;
case bfd_arch_m68hc12:
tdep->stack_correction = 0;
+ tdep->prologue = m6812_prologue;
break;
default: