/* Target-dependent code for Hitachi Super-H, for GDB. Copyright 1993, 1994, 1995, 1996, 1997, 1998 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. */ /* Contributed by Steve Chamberlain sac@cygnus.com */ #include "defs.h" #include "frame.h" #include "obstack.h" #include "symtab.h" #include "symfile.h" #include "gdbtypes.h" #include "gdbcmd.h" #include "gdbcore.h" #include "value.h" #include "dis-asm.h" #include "inferior.h" /* for BEFORE_TEXT_END etc. */ #include "gdb_string.h" /* A set of original names, to be used when restoring back to generic registers from a specific set. */ /* *INDENT-OFF* */ static char *sh_generic_reg_names[] = { "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "pc", "pr", "gbr", "vbr", "mach", "macl", "sr", "fpul", "fpscr", "fr0", "fr1", "fr2", "fr3", "fr4", "fr5", "fr6", "fr7", "fr8", "fr9", "fr10", "fr11", "fr12", "fr13", "fr14", "fr15", "ssr", "spc", "r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0", "r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1", }; static char *sh_reg_names[] = { "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "pc", "pr", "gbr", "vbr", "mach", "macl", "sr", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", }; static char *sh3_reg_names[] = { "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "pc", "pr", "gbr", "vbr", "mach", "macl", "sr", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "ssr", "spc", "r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0", "r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1" }; static char *sh3e_reg_names[] = { "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", "pc", "pr", "gbr", "vbr", "mach", "macl", "sr", "fpul", "fpscr", "fr0", "fr1", "fr2", "fr3", "fr4", "fr5", "fr6", "fr7", "fr8", "fr9", "fr10", "fr11", "fr12", "fr13", "fr14", "fr15", "ssr", "spc", "r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0", "r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1", }; /* *INDENT-ON* */ char **sh_register_names = sh_generic_reg_names; struct { char **regnames; int mach; } sh_processor_type_table[] = { { sh_reg_names, bfd_mach_sh } , { sh3_reg_names, bfd_mach_sh3 } , { sh3e_reg_names, bfd_mach_sh3e } , { sh3e_reg_names, bfd_mach_sh4 } , { NULL, 0 } }; /* Prologue looks like [mov.l ,@-r15]... [sts.l pr,@-r15] [mov.l r14,@-r15] [mov r15,r14] */ #define IS_STS(x) ((x) == 0x4f22) #define IS_PUSH(x) (((x) & 0xff0f) == 0x2f06) #define GET_PUSHED_REG(x) (((x) >> 4) & 0xf) #define IS_MOV_SP_FP(x) ((x) == 0x6ef3) #define IS_ADD_SP(x) (((x) & 0xff00) == 0x7f00) #define IS_MOV_R3(x) (((x) & 0xff00) == 0x1a00) #define IS_SHLL_R3(x) ((x) == 0x4300) #define IS_ADD_R3SP(x) ((x) == 0x3f3c) #define IS_FMOV(x) (((x) & 0xf00f) == 0xf00b) #define FPSCR_SZ (1 << 20) /* Should call_function allocate stack space for a struct return? */ int sh_use_struct_convention (gcc_p, type) int gcc_p; struct type *type; { return (TYPE_LENGTH (type) > 1); } /* Skip any prologue before the guts of a function */ CORE_ADDR sh_skip_prologue (start_pc) CORE_ADDR start_pc; { int w; w = read_memory_integer (start_pc, 2); while (IS_STS (w) || IS_FMOV (w) || IS_PUSH (w) || IS_MOV_SP_FP (w) || IS_MOV_R3 (w) || IS_ADD_R3SP (w) || IS_ADD_SP (w) || IS_SHLL_R3 (w)) { start_pc += 2; w = read_memory_integer (start_pc, 2); } return start_pc; } /* Disassemble an instruction. */ int gdb_print_insn_sh (memaddr, info) bfd_vma memaddr; disassemble_info *info; { if (TARGET_BYTE_ORDER == BIG_ENDIAN) return print_insn_sh (memaddr, info); else return print_insn_shl (memaddr, info); } /* 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 us, the frame address is its stack pointer value, so we look up the function prologue to determine the caller's sp value, and return it. */ CORE_ADDR sh_frame_chain (frame) struct frame_info *frame; { if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) return frame->frame; /* dummy frame same as caller's frame */ if (!inside_entry_file (frame->pc)) return read_memory_integer (FRAME_FP (frame) + frame->f_offset, 4); else return 0; } /* 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 sh_find_callers_reg (fi, regnum) struct frame_info *fi; int regnum; { struct frame_saved_regs fsr; for (; fi; fi = fi->next) if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) /* When the caller requests PR from the dummy frame, we return PC because that's where the previous routine appears to have done a call from. */ return generic_read_register_dummy (fi->pc, fi->frame, regnum); else { FRAME_FIND_SAVED_REGS (fi, fsr); if (fsr.regs[regnum] != 0) return read_memory_integer (fsr.regs[regnum], REGISTER_RAW_SIZE (regnum)); } return read_register (regnum); } /* 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. */ void sh_frame_find_saved_regs (fi, fsr) struct frame_info *fi; struct frame_saved_regs *fsr; { int where[NUM_REGS]; int rn; int have_fp = 0; int depth; int pc; int opc; int insn; int r3_val = 0; char *dummy_regs = generic_find_dummy_frame (fi->pc, fi->frame); if (dummy_regs) { /* DANGER! This is ONLY going to work if the char buffer format of the saved registers is byte-for-byte identical to the CORE_ADDR regs[NUM_REGS] format used by struct frame_saved_regs! */ memcpy (&fsr->regs, dummy_regs, sizeof (fsr)); return; } opc = pc = get_pc_function_start (fi->pc); insn = read_memory_integer (pc, 2); fi->leaf_function = 1; fi->f_offset = 0; for (rn = 0; rn < NUM_REGS; rn++) where[rn] = -1; depth = 0; /* Loop around examining the prologue insns until we find something that does not appear to be part of the prologue. But give up after 20 of them, since we're getting silly then. */ while (pc < opc + 20 * 2) { /* See where the registers will be saved to */ if (IS_PUSH (insn)) { pc += 2; rn = GET_PUSHED_REG (insn); where[rn] = depth; insn = read_memory_integer (pc, 2); depth += 4; } else if (IS_STS (insn)) { pc += 2; where[PR_REGNUM] = depth; insn = read_memory_integer (pc, 2); /* If we're storing the pr then this isn't a leaf */ fi->leaf_function = 0; depth += 4; } else if (IS_MOV_R3 (insn)) { r3_val = ((insn & 0xff) ^ 0x80) - 0x80; pc += 2; insn = read_memory_integer (pc, 2); } else if (IS_SHLL_R3 (insn)) { r3_val <<= 1; pc += 2; insn = read_memory_integer (pc, 2); } else if (IS_ADD_R3SP (insn)) { depth += -r3_val; pc += 2; insn = read_memory_integer (pc, 2); } else if (IS_ADD_SP (insn)) { pc += 2; depth -= ((insn & 0xff) ^ 0x80) - 0x80; insn = read_memory_integer (pc, 2); } else if (IS_FMOV (insn)) { pc += 2; insn = read_memory_integer (pc, 2); if (read_register (FPSCR_REGNUM) & FPSCR_SZ) { depth += 8; } else { depth += 4; } } else break; } /* Now we know how deep things are, we can work out their addresses */ for (rn = 0; rn < NUM_REGS; rn++) { if (where[rn] >= 0) { if (rn == FP_REGNUM) have_fp = 1; fsr->regs[rn] = fi->frame - where[rn] + depth - 4; } else { fsr->regs[rn] = 0; } } if (have_fp) { fsr->regs[SP_REGNUM] = read_memory_integer (fsr->regs[FP_REGNUM], 4); } else { fsr->regs[SP_REGNUM] = fi->frame - 4; } fi->f_offset = depth - where[FP_REGNUM] - 4; /* Work out the return pc - either from the saved pr or the pr value */ } /* initialize the extra info saved in a FRAME */ void sh_init_extra_frame_info (fromleaf, fi) int fromleaf; struct frame_info *fi; { struct frame_saved_regs fsr; if (fi->next) fi->pc = FRAME_SAVED_PC (fi->next); 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->return_pc = generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM); fi->f_offset = -(CALL_DUMMY_LENGTH + 4); fi->leaf_function = 0; return; } else { FRAME_FIND_SAVED_REGS (fi, fsr); fi->return_pc = sh_find_callers_reg (fi, PR_REGNUM); } } /* Discard from the stack the innermost frame, restoring all saved registers. */ void sh_pop_frame () { register struct frame_info *frame = get_current_frame (); register CORE_ADDR fp; register int regnum; struct frame_saved_regs fsr; if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) generic_pop_dummy_frame (); else { fp = FRAME_FP (frame); get_frame_saved_regs (frame, &fsr); /* Copy regs from where they were saved in the frame */ for (regnum = 0; regnum < NUM_REGS; regnum++) if (fsr.regs[regnum]) write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); write_register (PC_REGNUM, frame->return_pc); write_register (SP_REGNUM, fp + 4); } flush_cached_frames (); } /* Function: push_arguments Setup the function arguments for calling a function in the inferior. On the Hitachi SH architecture, there are four registers (R4 to R7) which are dedicated for passing function arguments. Up to the first four 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 larger than 4 bytes may be split between two or more registers. If there are not enough registers free, an argument may be passed partly in a register (or registers), and partly on the stack. This includes doubles, long longs, and larger aggregates. As far as I know, there is no upper limit to the size of aggregates that will be passed in this way; in other words, the convention of passing a pointer to a large aggregate instead of a copy is not used. An exceptional case exists for struct arguments (and possibly other aggregates such as arrays) if the size is larger than 4 bytes but not a multiple of 4 bytes. In this case the argument is never split between the registers and the stack, but instead is copied in its entirety onto the stack, AND also copied into as many registers as there is room for. In other words, space in registers permitting, two copies of the same argument are passed in. As far as I can tell, only the one on the stack is used, although that may be a function of the level of compiler optimization. I suspect this is a compiler bug. Arguments of these odd sizes are left-justified within the word (as opposed to arguments smaller than 4 bytes, which are right-justified). If the function is to return an aggregate type such as a struct, it is either returned in the normal return value register R0 (if its size is no greater than one byte), or else the caller must allocate space into which the callee will copy the return value (if the size is greater than one byte). In this case, a pointer to the return value location is passed into the callee in register R2, which does not displace any of the other arguments passed in via registers R4 to R7. */ CORE_ADDR sh_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; { 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; /* The "struct return pointer" pseudo-argument has its own dedicated register */ if (struct_return) write_register (STRUCT_RETURN_REGNUM, 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)); if (len < 4) { /* value gets right-justified in the register or stack word */ memcpy (valbuf + (4 - len), (char *) VALUE_CONTENTS (args[argnum]), len); val = valbuf; } else val = (char *) VALUE_CONTENTS (args[argnum]); 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); } /* 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: push_return_address (pc) Set up the return address for the inferior function call. Needed for targets where we don't actually execute a JSR/BSR instruction */ CORE_ADDR sh_push_return_address (pc, sp) CORE_ADDR pc; CORE_ADDR sp; { write_register (PR_REGNUM, CALL_DUMMY_ADDRESS ()); return sp; } /* Function: fix_call_dummy Poke the callee function's address into the destination part of the CALL_DUMMY. The address is actually stored in a data word following the actualy CALL_DUMMY instructions, which will load it into a register using PC-relative addressing. This function expects the CALL_DUMMY to look like this: mov.w @(2,PC), R8 jsr @R8 nop trap */ #if 0 void sh_fix_call_dummy (dummy, pc, fun, nargs, args, type, gcc_p) char *dummy; CORE_ADDR pc; CORE_ADDR fun; int nargs; value_ptr *args; struct type *type; int gcc_p; { *(unsigned long *) (dummy + 8) = fun; } #endif /* Modify the actual processor type. */ int sh_target_architecture_hook (ap) const bfd_arch_info_type *ap; { int i, j; if (ap->arch != bfd_arch_sh) return 0; for (i = 0; sh_processor_type_table[i].regnames != NULL; i++) { if (sh_processor_type_table[i].mach == ap->mach) { sh_register_names = sh_processor_type_table[i].regnames; return 1; } } internal_error ("Architecture `%s' unreconized", ap->printable_name); } /* Print the registers in a form similar to the E7000 */ static void sh_show_regs (args, from_tty) char *args; int from_tty; { int cpu; if (TARGET_ARCHITECTURE->arch == bfd_arch_sh) cpu = TARGET_ARCHITECTURE->mach; else cpu = 0; /* FIXME: sh4 has more registers */ if (cpu == bfd_mach_sh4) cpu = bfd_mach_sh3; printf_filtered ("PC=%s SR=%08lx PR=%08lx MACH=%08lx MACHL=%08lx\n", paddr (read_register (PC_REGNUM)), (long) read_register (SR_REGNUM), (long) read_register (PR_REGNUM), (long) read_register (MACH_REGNUM), (long) read_register (MACL_REGNUM)); printf_filtered ("GBR=%08lx VBR=%08lx", (long) read_register (GBR_REGNUM), (long) read_register (VBR_REGNUM)); if (cpu == bfd_mach_sh3 || cpu == bfd_mach_sh3e) { printf_filtered (" SSR=%08lx SPC=%08lx", (long) read_register (SSR_REGNUM), (long) read_register (SPC_REGNUM)); if (cpu == bfd_mach_sh3e) { printf_filtered (" FPUL=%08lx FPSCR=%08lx", (long) read_register (FPUL_REGNUM), (long) read_register (FPSCR_REGNUM)); } } printf_filtered ("\nR0-R7 %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", (long) read_register (0), (long) read_register (1), (long) read_register (2), (long) read_register (3), (long) read_register (4), (long) read_register (5), (long) read_register (6), (long) read_register (7)); printf_filtered ("R8-R15 %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", (long) read_register (8), (long) read_register (9), (long) read_register (10), (long) read_register (11), (long) read_register (12), (long) read_register (13), (long) read_register (14), (long) read_register (15)); if (cpu == bfd_mach_sh3e) { printf_filtered ("FP0-FP7 %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", (long) read_register (FP0_REGNUM + 0), (long) read_register (FP0_REGNUM + 1), (long) read_register (FP0_REGNUM + 2), (long) read_register (FP0_REGNUM + 3), (long) read_register (FP0_REGNUM + 4), (long) read_register (FP0_REGNUM + 5), (long) read_register (FP0_REGNUM + 6), (long) read_register (FP0_REGNUM + 7)); printf_filtered ("FP8-FP15 %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", (long) read_register (FP0_REGNUM + 8), (long) read_register (FP0_REGNUM + 9), (long) read_register (FP0_REGNUM + 10), (long) read_register (FP0_REGNUM + 11), (long) read_register (FP0_REGNUM + 12), (long) read_register (FP0_REGNUM + 13), (long) read_register (FP0_REGNUM + 14), (long) read_register (FP0_REGNUM + 15)); } } /* Function: extract_return_value Find a function's return value in the appropriate registers (in regbuf), and copy it into valbuf. */ void sh_extract_return_value (type, regbuf, valbuf) struct type *type; void *regbuf; void *valbuf; { int len = TYPE_LENGTH (type); if (len <= 4) memcpy (valbuf, ((char *) regbuf) + 4 - len, len); else if (len <= 8) memcpy (valbuf, ((char *) regbuf) + 8 - len, len); else error ("bad size for return value"); } void _initialize_sh_tdep () { struct cmd_list_element *c; tm_print_insn = gdb_print_insn_sh; target_architecture_hook = sh_target_architecture_hook; add_com ("regs", class_vars, sh_show_regs, "Print all registers"); }