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- /* Target-dependent code for the 32-bit OpenRISC 1000, for the GDB.
- Copyright (C) 2008-2022 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 3 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, see <http://www.gnu.org/licenses/>. */
- #include "defs.h"
- #include "frame.h"
- #include "inferior.h"
- #include "symtab.h"
- #include "value.h"
- #include "gdbcmd.h"
- #include "language.h"
- #include "gdbcore.h"
- #include "symfile.h"
- #include "objfiles.h"
- #include "gdbtypes.h"
- #include "target.h"
- #include "regcache.h"
- #include "safe-ctype.h"
- #include "block.h"
- #include "reggroups.h"
- #include "arch-utils.h"
- #include "frame-unwind.h"
- #include "frame-base.h"
- #include "dwarf2/frame.h"
- #include "trad-frame.h"
- #include "regset.h"
- #include "remote.h"
- #include "target-descriptions.h"
- #include <inttypes.h>
- #include "dis-asm.h"
- #include "gdbarch.h"
- /* OpenRISC specific includes. */
- #include "or1k-tdep.h"
- #include "features/or1k.c"
- /* Global debug flag. */
- static bool or1k_debug = false;
- static void
- show_or1k_debug (struct ui_file *file, int from_tty,
- struct cmd_list_element *c, const char *value)
- {
- gdb_printf (file, _("OpenRISC debugging is %s.\n"), value);
- }
- /* The target-dependent structure for gdbarch. */
- struct or1k_gdbarch_tdep : gdbarch_tdep
- {
- int bytes_per_word = 0;
- int bytes_per_address = 0;
- CGEN_CPU_DESC gdb_cgen_cpu_desc = nullptr;
- };
- /* Support functions for the architecture definition. */
- /* Get an instruction from memory. */
- static ULONGEST
- or1k_fetch_instruction (struct gdbarch *gdbarch, CORE_ADDR addr)
- {
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- gdb_byte buf[OR1K_INSTLEN];
- if (target_read_code (addr, buf, OR1K_INSTLEN)) {
- memory_error (TARGET_XFER_E_IO, addr);
- }
- return extract_unsigned_integer (buf, OR1K_INSTLEN, byte_order);
- }
- /* Generic function to read bits from an instruction. */
- static bool
- or1k_analyse_inst (uint32_t inst, const char *format, ...)
- {
- /* Break out each field in turn, validating as we go. */
- va_list ap;
- int i;
- int iptr = 0; /* Instruction pointer */
- va_start (ap, format);
- for (i = 0; 0 != format[i];)
- {
- const char *start_ptr;
- char *end_ptr;
- uint32_t bits; /* Bit substring of interest */
- uint32_t width; /* Substring width */
- uint32_t *arg_ptr;
- switch (format[i])
- {
- case ' ':
- i++;
- break; /* Formatting: ignored */
- case '0':
- case '1': /* Constant bit field */
- bits = (inst >> (OR1K_INSTBITLEN - iptr - 1)) & 0x1;
- if ((format[i] - '0') != bits)
- return false;
- iptr++;
- i++;
- break;
- case '%': /* Bit field */
- i++;
- start_ptr = &(format[i]);
- width = strtoul (start_ptr, &end_ptr, 10);
- /* Check we got something, and if so skip on. */
- if (start_ptr == end_ptr)
- error (_("bitstring \"%s\" at offset %d has no length field."),
- format, i);
- i += end_ptr - start_ptr;
- /* Look for and skip the terminating 'b'. If it's not there, we
- still give a fatal error, because these are fixed strings that
- just should not be wrong. */
- if ('b' != format[i++])
- error (_("bitstring \"%s\" at offset %d has no terminating 'b'."),
- format, i);
- /* Break out the field. There is a special case with a bit width
- of 32. */
- if (32 == width)
- bits = inst;
- else
- bits =
- (inst >> (OR1K_INSTBITLEN - iptr - width)) & ((1 << width) - 1);
- arg_ptr = va_arg (ap, uint32_t *);
- *arg_ptr = bits;
- iptr += width;
- break;
- default:
- error (_("invalid character in bitstring \"%s\" at offset %d."),
- format, i);
- break;
- }
- }
- /* Is the length OK? */
- gdb_assert (OR1K_INSTBITLEN == iptr);
- return true; /* Success */
- }
- /* This is used to parse l.addi instructions during various prologue
- analysis routines. The l.addi instruction has semantics:
- assembly: l.addi rD,rA,I
- implementation: rD = rA + sign_extend(Immediate)
- The rd_ptr, ra_ptr and simm_ptr must be non NULL pointers and are used
- to store the parse results. Upon successful parsing true is returned,
- false on failure. */
- static bool
- or1k_analyse_l_addi (uint32_t inst, unsigned int *rd_ptr,
- unsigned int *ra_ptr, int *simm_ptr)
- {
- /* Instruction fields */
- uint32_t rd, ra, i;
- if (or1k_analyse_inst (inst, "10 0111 %5b %5b %16b", &rd, &ra, &i))
- {
- /* Found it. Construct the result fields. */
- *rd_ptr = (unsigned int) rd;
- *ra_ptr = (unsigned int) ra;
- *simm_ptr = (int) (((i & 0x8000) == 0x8000) ? 0xffff0000 | i : i);
- return true; /* Success */
- }
- else
- return false; /* Failure */
- }
- /* This is used to to parse store instructions during various prologue
- analysis routines. The l.sw instruction has semantics:
- assembly: l.sw I(rA),rB
- implementation: store rB contents to memory at effective address of
- rA + sign_extend(Immediate)
- The simm_ptr, ra_ptr and rb_ptr must be non NULL pointers and are used
- to store the parse results. Upon successful parsing true is returned,
- false on failure. */
- static bool
- or1k_analyse_l_sw (uint32_t inst, int *simm_ptr, unsigned int *ra_ptr,
- unsigned int *rb_ptr)
- {
- /* Instruction fields */
- uint32_t ihi, ilo, ra, rb;
- if (or1k_analyse_inst (inst, "11 0101 %5b %5b %5b %11b", &ihi, &ra, &rb,
- &ilo))
- {
- /* Found it. Construct the result fields. */
- *simm_ptr = (int) ((ihi << 11) | ilo);
- *simm_ptr |= ((ihi & 0x10) == 0x10) ? 0xffff0000 : 0;
- *ra_ptr = (unsigned int) ra;
- *rb_ptr = (unsigned int) rb;
- return true; /* Success */
- }
- else
- return false; /* Failure */
- }
- /* Functions defining the architecture. */
- /* Implement the return_value gdbarch method. */
- static enum return_value_convention
- or1k_return_value (struct gdbarch *gdbarch, struct value *functype,
- struct type *valtype, struct regcache *regcache,
- gdb_byte *readbuf, const gdb_byte *writebuf)
- {
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- enum type_code rv_type = valtype->code ();
- unsigned int rv_size = TYPE_LENGTH (valtype);
- or1k_gdbarch_tdep *tdep = (or1k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- int bpw = tdep->bytes_per_word;
- /* Deal with struct/union as addresses. If an array won't fit in a
- single register it is returned as address. Anything larger than 2
- registers needs to also be passed as address (matches gcc
- default_return_in_memory). */
- if ((TYPE_CODE_STRUCT == rv_type) || (TYPE_CODE_UNION == rv_type)
- || ((TYPE_CODE_ARRAY == rv_type) && (rv_size > bpw))
- || (rv_size > 2 * bpw))
- {
- if (readbuf != NULL)
- {
- ULONGEST tmp;
- regcache_cooked_read_unsigned (regcache, OR1K_RV_REGNUM, &tmp);
- read_memory (tmp, readbuf, rv_size);
- }
- if (writebuf != NULL)
- {
- ULONGEST tmp;
- regcache_cooked_read_unsigned (regcache, OR1K_RV_REGNUM, &tmp);
- write_memory (tmp, writebuf, rv_size);
- }
- return RETURN_VALUE_ABI_RETURNS_ADDRESS;
- }
- if (rv_size <= bpw)
- {
- /* Up to one word scalars are returned in R11. */
- if (readbuf != NULL)
- {
- ULONGEST tmp;
- regcache_cooked_read_unsigned (regcache, OR1K_RV_REGNUM, &tmp);
- store_unsigned_integer (readbuf, rv_size, byte_order, tmp);
- }
- if (writebuf != NULL)
- {
- gdb_byte *buf = XCNEWVEC(gdb_byte, bpw);
- if (BFD_ENDIAN_BIG == byte_order)
- memcpy (buf + (sizeof (gdb_byte) * bpw) - rv_size, writebuf,
- rv_size);
- else
- memcpy (buf, writebuf, rv_size);
- regcache->cooked_write (OR1K_RV_REGNUM, buf);
- free (buf);
- }
- }
- else
- {
- /* 2 word scalars are returned in r11/r12 (with the MS word in r11). */
- if (readbuf != NULL)
- {
- ULONGEST tmp_lo;
- ULONGEST tmp_hi;
- ULONGEST tmp;
- regcache_cooked_read_unsigned (regcache, OR1K_RV_REGNUM,
- &tmp_hi);
- regcache_cooked_read_unsigned (regcache, OR1K_RV_REGNUM + 1,
- &tmp_lo);
- tmp = (tmp_hi << (bpw * 8)) | tmp_lo;
- store_unsigned_integer (readbuf, rv_size, byte_order, tmp);
- }
- if (writebuf != NULL)
- {
- gdb_byte *buf_lo = XCNEWVEC(gdb_byte, bpw);
- gdb_byte *buf_hi = XCNEWVEC(gdb_byte, bpw);
- /* This is cheating. We assume that we fit in 2 words exactly,
- which wouldn't work if we had (say) a 6-byte scalar type on a
- big endian architecture (with the OpenRISC 1000 usually is). */
- memcpy (buf_hi, writebuf, rv_size - bpw);
- memcpy (buf_lo, writebuf + bpw, bpw);
- regcache->cooked_write (OR1K_RV_REGNUM, buf_hi);
- regcache->cooked_write (OR1K_RV_REGNUM + 1, buf_lo);
- free (buf_lo);
- free (buf_hi);
- }
- }
- return RETURN_VALUE_REGISTER_CONVENTION;
- }
- /* OR1K always uses a l.trap instruction for breakpoints. */
- constexpr gdb_byte or1k_break_insn[] = {0x21, 0x00, 0x00, 0x01};
- typedef BP_MANIPULATION (or1k_break_insn) or1k_breakpoint;
- static int
- or1k_delay_slot_p (struct gdbarch *gdbarch, CORE_ADDR pc)
- {
- const CGEN_INSN *insn;
- CGEN_FIELDS tmp_fields;
- or1k_gdbarch_tdep *tdep = (or1k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- insn = cgen_lookup_insn (tdep->gdb_cgen_cpu_desc,
- NULL,
- or1k_fetch_instruction (gdbarch, pc),
- NULL, 32, &tmp_fields, 0);
- /* NULL here would mean the last instruction was not understood by cgen.
- This should not usually happen, but if does its not a delay slot. */
- if (insn == NULL)
- return 0;
- /* TODO: we should add a delay slot flag to the CGEN_INSN and remove
- this hard coded test. */
- return ((CGEN_INSN_NUM (insn) == OR1K_INSN_L_J)
- || (CGEN_INSN_NUM (insn) == OR1K_INSN_L_JAL)
- || (CGEN_INSN_NUM (insn) == OR1K_INSN_L_JR)
- || (CGEN_INSN_NUM (insn) == OR1K_INSN_L_JALR)
- || (CGEN_INSN_NUM (insn) == OR1K_INSN_L_BNF)
- || (CGEN_INSN_NUM (insn) == OR1K_INSN_L_BF));
- }
- /* Implement the single_step_through_delay gdbarch method. */
- static int
- or1k_single_step_through_delay (struct gdbarch *gdbarch,
- struct frame_info *this_frame)
- {
- ULONGEST val;
- CORE_ADDR ppc;
- CORE_ADDR npc;
- struct regcache *regcache = get_current_regcache ();
- /* Get the previous and current instruction addresses. If they are not
- adjacent, we cannot be in a delay slot. */
- regcache_cooked_read_unsigned (regcache, OR1K_PPC_REGNUM, &val);
- ppc = (CORE_ADDR) val;
- regcache_cooked_read_unsigned (regcache, OR1K_NPC_REGNUM, &val);
- npc = (CORE_ADDR) val;
- if (0x4 != (npc - ppc))
- return 0;
- return or1k_delay_slot_p (gdbarch, ppc);
- }
- /* or1k_software_single_step() is called just before we want to resume
- the inferior, if we want to single-step it but there is no hardware
- or kernel single-step support (OpenRISC on GNU/Linux for example). We
- find the target of the coming instruction skipping over delay slots
- and breakpoint it. */
- std::vector<CORE_ADDR>
- or1k_software_single_step (struct regcache *regcache)
- {
- struct gdbarch *gdbarch = regcache->arch ();
- CORE_ADDR pc, next_pc;
- pc = regcache_read_pc (regcache);
- next_pc = pc + 4;
- if (or1k_delay_slot_p (gdbarch, pc))
- next_pc += 4;
- return {next_pc};
- }
- /* Name for or1k general registers. */
- static const char *const or1k_reg_names[OR1K_NUM_REGS] = {
- /* general purpose registers */
- "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
- "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
- "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
- "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
- /* previous program counter, next program counter and status register */
- "ppc", "npc", "sr"
- };
- static int
- or1k_is_arg_reg (unsigned int regnum)
- {
- return (OR1K_FIRST_ARG_REGNUM <= regnum)
- && (regnum <= OR1K_LAST_ARG_REGNUM);
- }
- static int
- or1k_is_callee_saved_reg (unsigned int regnum)
- {
- return (OR1K_FIRST_SAVED_REGNUM <= regnum) && (0 == regnum % 2);
- }
- /* Implement the skip_prologue gdbarch method. */
- static CORE_ADDR
- or1k_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
- {
- CORE_ADDR start_pc;
- CORE_ADDR addr;
- uint32_t inst;
- unsigned int ra, rb, rd; /* for instruction analysis */
- int simm;
- int frame_size = 0;
- /* Try using SAL first if we have symbolic information available. This
- only works for DWARF 2, not STABS. */
- if (find_pc_partial_function (pc, NULL, &start_pc, NULL))
- {
- CORE_ADDR prologue_end = skip_prologue_using_sal (gdbarch, pc);
- if (0 != prologue_end)
- {
- struct symtab_and_line prologue_sal = find_pc_line (start_pc, 0);
- struct compunit_symtab *compunit
- = prologue_sal.symtab->compunit ();
- const char *debug_format = compunit->debugformat ();
- if ((NULL != debug_format)
- && (strlen ("dwarf") <= strlen (debug_format))
- && (0 == strncasecmp ("dwarf", debug_format, strlen ("dwarf"))))
- return (prologue_end > pc) ? prologue_end : pc;
- }
- }
- /* Look to see if we can find any of the standard prologue sequence. All
- quite difficult, since any or all of it may be missing. So this is
- just a best guess! */
- addr = pc; /* Where we have got to */
- inst = or1k_fetch_instruction (gdbarch, addr);
- /* Look for the new stack pointer being set up. */
- if (or1k_analyse_l_addi (inst, &rd, &ra, &simm)
- && (OR1K_SP_REGNUM == rd) && (OR1K_SP_REGNUM == ra)
- && (simm < 0) && (0 == (simm % 4)))
- {
- frame_size = -simm;
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- }
- /* Look for the frame pointer being manipulated. */
- if (or1k_analyse_l_sw (inst, &simm, &ra, &rb)
- && (OR1K_SP_REGNUM == ra) && (OR1K_FP_REGNUM == rb)
- && (simm >= 0) && (0 == (simm % 4)))
- {
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- gdb_assert (or1k_analyse_l_addi (inst, &rd, &ra, &simm)
- && (OR1K_FP_REGNUM == rd) && (OR1K_SP_REGNUM == ra)
- && (simm == frame_size));
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- }
- /* Look for the link register being saved. */
- if (or1k_analyse_l_sw (inst, &simm, &ra, &rb)
- && (OR1K_SP_REGNUM == ra) && (OR1K_LR_REGNUM == rb)
- && (simm >= 0) && (0 == (simm % 4)))
- {
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- }
- /* Look for arguments or callee-saved register being saved. The register
- must be one of the arguments (r3-r8) or the 10 callee saved registers
- (r10, r12, r14, r16, r18, r20, r22, r24, r26, r28, r30). The base
- register must be the FP (for the args) or the SP (for the callee_saved
- registers). */
- while (1)
- {
- if (or1k_analyse_l_sw (inst, &simm, &ra, &rb)
- && (((OR1K_FP_REGNUM == ra) && or1k_is_arg_reg (rb))
- || ((OR1K_SP_REGNUM == ra) && or1k_is_callee_saved_reg (rb)))
- && (0 == (simm % 4)))
- {
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- }
- else
- {
- /* Nothing else to look for. We have found the end of the
- prologue. */
- break;
- }
- }
- return addr;
- }
- /* Implement the frame_align gdbarch method. */
- static CORE_ADDR
- or1k_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
- {
- return align_down (sp, OR1K_STACK_ALIGN);
- }
- /* Implement the unwind_pc gdbarch method. */
- static CORE_ADDR
- or1k_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
- {
- CORE_ADDR pc;
- if (or1k_debug)
- gdb_printf (gdb_stdlog, "or1k_unwind_pc, next_frame=%d\n",
- frame_relative_level (next_frame));
- pc = frame_unwind_register_unsigned (next_frame, OR1K_NPC_REGNUM);
- if (or1k_debug)
- gdb_printf (gdb_stdlog, "or1k_unwind_pc, pc=%s\n",
- paddress (gdbarch, pc));
- return pc;
- }
- /* Implement the unwind_sp gdbarch method. */
- static CORE_ADDR
- or1k_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
- {
- CORE_ADDR sp;
- if (or1k_debug)
- gdb_printf (gdb_stdlog, "or1k_unwind_sp, next_frame=%d\n",
- frame_relative_level (next_frame));
- sp = frame_unwind_register_unsigned (next_frame, OR1K_SP_REGNUM);
- if (or1k_debug)
- gdb_printf (gdb_stdlog, "or1k_unwind_sp, sp=%s\n",
- paddress (gdbarch, sp));
- return sp;
- }
- /* Implement the push_dummy_code gdbarch method. */
- static CORE_ADDR
- or1k_push_dummy_code (struct gdbarch *gdbarch, CORE_ADDR sp,
- CORE_ADDR function, struct value **args, int nargs,
- struct type *value_type, CORE_ADDR * real_pc,
- CORE_ADDR * bp_addr, struct regcache *regcache)
- {
- CORE_ADDR bp_slot;
- /* Reserve enough room on the stack for our breakpoint instruction. */
- bp_slot = sp - 4;
- /* Store the address of that breakpoint. */
- *bp_addr = bp_slot;
- /* keeping the stack aligned. */
- sp = or1k_frame_align (gdbarch, bp_slot);
- /* The call starts at the callee's entry point. */
- *real_pc = function;
- return sp;
- }
- /* Implement the push_dummy_call gdbarch method. */
- static CORE_ADDR
- or1k_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
- struct regcache *regcache, CORE_ADDR bp_addr,
- int nargs, struct value **args, CORE_ADDR sp,
- function_call_return_method return_method,
- CORE_ADDR struct_addr)
- {
- int argreg;
- int argnum;
- int first_stack_arg;
- int stack_offset = 0;
- int heap_offset = 0;
- CORE_ADDR heap_sp = sp - 128;
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- or1k_gdbarch_tdep *tdep = (or1k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- int bpa = tdep->bytes_per_address;
- int bpw = tdep->bytes_per_word;
- struct type *func_type = value_type (function);
- /* Return address */
- regcache_cooked_write_unsigned (regcache, OR1K_LR_REGNUM, bp_addr);
- /* Register for the next argument. */
- argreg = OR1K_FIRST_ARG_REGNUM;
- /* Location for a returned structure. This is passed as a silent first
- argument. */
- if (return_method == return_method_struct)
- {
- regcache_cooked_write_unsigned (regcache, OR1K_FIRST_ARG_REGNUM,
- struct_addr);
- argreg++;
- }
- /* Put as many args as possible in registers. */
- for (argnum = 0; argnum < nargs; argnum++)
- {
- const gdb_byte *val;
- gdb_byte valbuf[sizeof (ULONGEST)];
- struct value *arg = args[argnum];
- struct type *arg_type = check_typedef (value_type (arg));
- int len = TYPE_LENGTH (arg_type);
- enum type_code typecode = arg_type->code ();
- if (func_type->has_varargs () && argnum >= func_type->num_fields ())
- break; /* end or regular args, varargs go to stack. */
- /* Extract the value, either a reference or the data. */
- if ((TYPE_CODE_STRUCT == typecode) || (TYPE_CODE_UNION == typecode)
- || (len > bpw * 2))
- {
- CORE_ADDR valaddr = value_address (arg);
- /* If the arg is fabricated (i.e. 3*i, instead of i) valaddr is
- undefined. */
- if (valaddr == 0)
- {
- /* The argument needs to be copied into the target space.
- Since the bottom of the stack is reserved for function
- arguments we store this at the these at the top growing
- down. */
- heap_offset += align_up (len, bpw);
- valaddr = heap_sp + heap_offset;
- write_memory (valaddr, value_contents (arg).data (), len);
- }
- /* The ABI passes all structures by reference, so get its
- address. */
- store_unsigned_integer (valbuf, bpa, byte_order, valaddr);
- len = bpa;
- val = valbuf;
- }
- else
- {
- /* Everything else, we just get the value. */
- val = value_contents (arg).data ();
- }
- /* Stick the value in a register. */
- if (len > bpw)
- {
- /* Big scalars use two registers, but need NOT be pair aligned. */
- if (argreg <= (OR1K_LAST_ARG_REGNUM - 1))
- {
- ULONGEST regval = extract_unsigned_integer (val, len,
- byte_order);
- unsigned int bits_per_word = bpw * 8;
- ULONGEST mask = (((ULONGEST) 1) << bits_per_word) - 1;
- ULONGEST lo = regval & mask;
- ULONGEST hi = regval >> bits_per_word;
- regcache_cooked_write_unsigned (regcache, argreg, hi);
- regcache_cooked_write_unsigned (regcache, argreg + 1, lo);
- argreg += 2;
- }
- else
- {
- /* Run out of regs */
- break;
- }
- }
- else if (argreg <= OR1K_LAST_ARG_REGNUM)
- {
- /* Smaller scalars fit in a single register. */
- regcache_cooked_write_unsigned
- (regcache, argreg, extract_unsigned_integer (val, len,
- byte_order));
- argreg++;
- }
- else
- {
- /* Ran out of regs. */
- break;
- }
- }
- first_stack_arg = argnum;
- /* If we get here with argnum < nargs, then arguments remain to be
- placed on the stack. This is tricky, since they must be pushed in
- reverse order and the stack in the end must be aligned. The only
- solution is to do it in two stages, the first to compute the stack
- size, the second to save the args. */
- for (argnum = first_stack_arg; argnum < nargs; argnum++)
- {
- struct value *arg = args[argnum];
- struct type *arg_type = check_typedef (value_type (arg));
- int len = TYPE_LENGTH (arg_type);
- enum type_code typecode = arg_type->code ();
- if ((TYPE_CODE_STRUCT == typecode) || (TYPE_CODE_UNION == typecode)
- || (len > bpw * 2))
- {
- /* Structures are passed as addresses. */
- sp -= bpa;
- }
- else
- {
- /* Big scalars use more than one word. Code here allows for
- future quad-word entities (e.g. long double.) */
- sp -= align_up (len, bpw);
- }
- /* Ensure our dummy heap doesn't touch the stack, this could only
- happen if we have many arguments including fabricated arguments. */
- gdb_assert (heap_offset == 0 || ((heap_sp + heap_offset) < sp));
- }
- sp = gdbarch_frame_align (gdbarch, sp);
- stack_offset = 0;
- /* Push the remaining args on the stack. */
- for (argnum = first_stack_arg; argnum < nargs; argnum++)
- {
- const gdb_byte *val;
- gdb_byte valbuf[sizeof (ULONGEST)];
- struct value *arg = args[argnum];
- struct type *arg_type = check_typedef (value_type (arg));
- int len = TYPE_LENGTH (arg_type);
- enum type_code typecode = arg_type->code ();
- /* The EABI passes structures that do not fit in a register by
- reference. In all other cases, pass the structure by value. */
- if ((TYPE_CODE_STRUCT == typecode) || (TYPE_CODE_UNION == typecode)
- || (len > bpw * 2))
- {
- store_unsigned_integer (valbuf, bpa, byte_order,
- value_address (arg));
- len = bpa;
- val = valbuf;
- }
- else
- val = value_contents (arg).data ();
- while (len > 0)
- {
- int partial_len = (len < bpw ? len : bpw);
- write_memory (sp + stack_offset, val, partial_len);
- stack_offset += align_up (partial_len, bpw);
- len -= partial_len;
- val += partial_len;
- }
- }
- /* Save the updated stack pointer. */
- regcache_cooked_write_unsigned (regcache, OR1K_SP_REGNUM, sp);
- if (heap_offset > 0)
- sp = heap_sp;
- return sp;
- }
- /* Support functions for frame handling. */
- /* Initialize a prologue cache
- We build a cache, saying where registers of the prev frame can be found
- from the data so far set up in this this.
- We also compute a unique ID for this frame, based on the function start
- address and the stack pointer (as it will be, even if it has yet to be
- computed.
- STACK FORMAT
- ============
- The OR1K has a falling stack frame and a simple prolog. The Stack
- pointer is R1 and the frame pointer R2. The frame base is therefore the
- address held in R2 and the stack pointer (R1) is the frame base of the
- next frame.
- l.addi r1,r1,-frame_size # SP now points to end of new stack frame
- The stack pointer may not be set up in a frameless function (e.g. a
- simple leaf function).
- l.sw fp_loc(r1),r2 # old FP saved in new stack frame
- l.addi r2,r1,frame_size # FP now points to base of new stack frame
- The frame pointer is not necessarily saved right at the end of the stack
- frame - OR1K saves enough space for any args to called functions right
- at the end (this is a difference from the Architecture Manual).
- l.sw lr_loc(r1),r9 # Link (return) address
- The link register is usually saved at fp_loc - 4. It may not be saved at
- all in a leaf function.
- l.sw reg_loc(r1),ry # Save any callee saved regs
- The offsets x for the callee saved registers generally (always?) rise in
- increments of 4, starting at fp_loc + 4. If the frame pointer is
- omitted (an option to GCC), then it may not be saved at all. There may
- be no callee saved registers.
- So in summary none of this may be present. However what is present
- seems always to follow this fixed order, and occur before any
- substantive code (it is possible for GCC to have more flexible
- scheduling of the prologue, but this does not seem to occur for OR1K).
- ANALYSIS
- ========
- This prolog is used, even for -O3 with GCC.
- All this analysis must allow for the possibility that the PC is in the
- middle of the prologue. Data in the cache should only be set up insofar
- as it has been computed.
- HOWEVER. The frame_id must be created with the SP *as it will be* at
- the end of the Prologue. Otherwise a recursive call, checking the frame
- with the PC at the start address will end up with the same frame_id as
- the caller.
- A suite of "helper" routines are used, allowing reuse for
- or1k_skip_prologue().
- Reportedly, this is only valid for frames less than 0x7fff in size. */
- static struct trad_frame_cache *
- or1k_frame_cache (struct frame_info *this_frame, void **prologue_cache)
- {
- struct gdbarch *gdbarch;
- struct trad_frame_cache *info;
- CORE_ADDR this_pc;
- CORE_ADDR this_sp;
- CORE_ADDR this_sp_for_id;
- int frame_size = 0;
- CORE_ADDR start_addr;
- CORE_ADDR end_addr;
- if (or1k_debug)
- gdb_printf (gdb_stdlog,
- "or1k_frame_cache, prologue_cache = %s\n",
- host_address_to_string (*prologue_cache));
- /* Nothing to do if we already have this info. */
- if (NULL != *prologue_cache)
- return (struct trad_frame_cache *) *prologue_cache;
- /* Get a new prologue cache and populate it with default values. */
- info = trad_frame_cache_zalloc (this_frame);
- *prologue_cache = info;
- /* Find the start address of this function (which is a normal frame, even
- if the next frame is the sentinel frame) and the end of its prologue. */
- this_pc = get_frame_pc (this_frame);
- find_pc_partial_function (this_pc, NULL, &start_addr, NULL);
- /* Get the stack pointer if we have one (if there's no process executing
- yet we won't have a frame. */
- this_sp = (NULL == this_frame) ? 0 :
- get_frame_register_unsigned (this_frame, OR1K_SP_REGNUM);
- /* Return early if GDB couldn't find the function. */
- if (start_addr == 0)
- {
- if (or1k_debug)
- gdb_printf (gdb_stdlog, " couldn't find function\n");
- /* JPB: 28-Apr-11. This is a temporary patch, to get round GDB
- crashing right at the beginning. Build the frame ID as best we
- can. */
- trad_frame_set_id (info, frame_id_build (this_sp, this_pc));
- return info;
- }
- /* The default frame base of this frame (for ID purposes only - frame
- base is an overloaded term) is its stack pointer. For now we use the
- value of the SP register in this frame. However if the PC is in the
- prologue of this frame, before the SP has been set up, then the value
- will actually be that of the prev frame, and we'll need to adjust it
- later. */
- trad_frame_set_this_base (info, this_sp);
- this_sp_for_id = this_sp;
- /* The default is to find the PC of the previous frame in the link
- register of this frame. This may be changed if we find the link
- register was saved on the stack. */
- trad_frame_set_reg_realreg (info, OR1K_NPC_REGNUM, OR1K_LR_REGNUM);
- /* We should only examine code that is in the prologue. This is all code
- up to (but not including) end_addr. We should only populate the cache
- while the address is up to (but not including) the PC or end_addr,
- whichever is first. */
- gdbarch = get_frame_arch (this_frame);
- end_addr = or1k_skip_prologue (gdbarch, start_addr);
- /* All the following analysis only occurs if we are in the prologue and
- have executed the code. Check we have a sane prologue size, and if
- zero we are frameless and can give up here. */
- if (end_addr < start_addr)
- error (_("end addr %s is less than start addr %s"),
- paddress (gdbarch, end_addr), paddress (gdbarch, start_addr));
- if (end_addr == start_addr)
- frame_size = 0;
- else
- {
- /* We have a frame. Look for the various components. */
- CORE_ADDR addr = start_addr; /* Where we have got to */
- uint32_t inst = or1k_fetch_instruction (gdbarch, addr);
- unsigned int ra, rb, rd; /* for instruction analysis */
- int simm;
- /* Look for the new stack pointer being set up. */
- if (or1k_analyse_l_addi (inst, &rd, &ra, &simm)
- && (OR1K_SP_REGNUM == rd) && (OR1K_SP_REGNUM == ra)
- && (simm < 0) && (0 == (simm % 4)))
- {
- frame_size = -simm;
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- /* If the PC has not actually got to this point, then the frame
- base will be wrong, and we adjust it.
- If we are past this point, then we need to populate the stack
- accordingly. */
- if (this_pc <= addr)
- {
- /* Only do if executing. */
- if (0 != this_sp)
- {
- this_sp_for_id = this_sp + frame_size;
- trad_frame_set_this_base (info, this_sp_for_id);
- }
- }
- else
- {
- /* We are past this point, so the stack pointer of the prev
- frame is frame_size greater than the stack pointer of this
- frame. */
- trad_frame_set_reg_value (info, OR1K_SP_REGNUM,
- this_sp + frame_size);
- }
- }
- /* From now on we are only populating the cache, so we stop once we
- get to either the end OR the current PC. */
- end_addr = (this_pc < end_addr) ? this_pc : end_addr;
- /* Look for the frame pointer being manipulated. */
- if ((addr < end_addr)
- && or1k_analyse_l_sw (inst, &simm, &ra, &rb)
- && (OR1K_SP_REGNUM == ra) && (OR1K_FP_REGNUM == rb)
- && (simm >= 0) && (0 == (simm % 4)))
- {
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- /* At this stage, we can find the frame pointer of the previous
- frame on the stack of the current frame. */
- trad_frame_set_reg_addr (info, OR1K_FP_REGNUM, this_sp + simm);
- /* Look for the new frame pointer being set up. */
- if ((addr < end_addr)
- && or1k_analyse_l_addi (inst, &rd, &ra, &simm)
- && (OR1K_FP_REGNUM == rd) && (OR1K_SP_REGNUM == ra)
- && (simm == frame_size))
- {
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- /* If we have got this far, the stack pointer of the previous
- frame is the frame pointer of this frame. */
- trad_frame_set_reg_realreg (info, OR1K_SP_REGNUM,
- OR1K_FP_REGNUM);
- }
- }
- /* Look for the link register being saved. */
- if ((addr < end_addr)
- && or1k_analyse_l_sw (inst, &simm, &ra, &rb)
- && (OR1K_SP_REGNUM == ra) && (OR1K_LR_REGNUM == rb)
- && (simm >= 0) && (0 == (simm % 4)))
- {
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- /* If the link register is saved in the this frame, it holds the
- value of the PC in the previous frame. This overwrites the
- previous information about finding the PC in the link
- register. */
- trad_frame_set_reg_addr (info, OR1K_NPC_REGNUM, this_sp + simm);
- }
- /* Look for arguments or callee-saved register being saved. The
- register must be one of the arguments (r3-r8) or the 10 callee
- saved registers (r10, r12, r14, r16, r18, r20, r22, r24, r26, r28,
- r30). The base register must be the FP (for the args) or the SP
- (for the callee_saved registers). */
- while (addr < end_addr)
- {
- if (or1k_analyse_l_sw (inst, &simm, &ra, &rb)
- && (((OR1K_FP_REGNUM == ra) && or1k_is_arg_reg (rb))
- || ((OR1K_SP_REGNUM == ra)
- && or1k_is_callee_saved_reg (rb)))
- && (0 == (simm % 4)))
- {
- addr += OR1K_INSTLEN;
- inst = or1k_fetch_instruction (gdbarch, addr);
- /* The register in the previous frame can be found at this
- location in this frame. */
- trad_frame_set_reg_addr (info, rb, this_sp + simm);
- }
- else
- break; /* Not a register save instruction. */
- }
- }
- /* Build the frame ID */
- trad_frame_set_id (info, frame_id_build (this_sp_for_id, start_addr));
- if (or1k_debug)
- {
- gdb_printf (gdb_stdlog, " this_sp_for_id = %s\n",
- paddress (gdbarch, this_sp_for_id));
- gdb_printf (gdb_stdlog, " start_addr = %s\n",
- paddress (gdbarch, start_addr));
- }
- return info;
- }
- /* Implement the this_id function for the stub unwinder. */
- static void
- or1k_frame_this_id (struct frame_info *this_frame,
- void **prologue_cache, struct frame_id *this_id)
- {
- struct trad_frame_cache *info = or1k_frame_cache (this_frame,
- prologue_cache);
- trad_frame_get_id (info, this_id);
- }
- /* Implement the prev_register function for the stub unwinder. */
- static struct value *
- or1k_frame_prev_register (struct frame_info *this_frame,
- void **prologue_cache, int regnum)
- {
- struct trad_frame_cache *info = or1k_frame_cache (this_frame,
- prologue_cache);
- return trad_frame_get_register (info, this_frame, regnum);
- }
- /* Data structures for the normal prologue-analysis-based unwinder. */
- static const struct frame_unwind or1k_frame_unwind = {
- "or1k prologue",
- NORMAL_FRAME,
- default_frame_unwind_stop_reason,
- or1k_frame_this_id,
- or1k_frame_prev_register,
- NULL,
- default_frame_sniffer,
- NULL,
- };
- /* Architecture initialization for OpenRISC 1000. */
- static struct gdbarch *
- or1k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
- {
- struct gdbarch *gdbarch;
- const struct bfd_arch_info *binfo;
- tdesc_arch_data_up tdesc_data;
- const struct target_desc *tdesc = info.target_desc;
- /* Find a candidate among the list of pre-declared architectures. */
- arches = gdbarch_list_lookup_by_info (arches, &info);
- if (NULL != arches)
- return arches->gdbarch;
- /* None found, create a new architecture from the information
- provided. Can't initialize all the target dependencies until we
- actually know which target we are talking to, but put in some defaults
- for now. */
- binfo = info.bfd_arch_info;
- or1k_gdbarch_tdep *tdep = new or1k_gdbarch_tdep;
- tdep->bytes_per_word = binfo->bits_per_word / binfo->bits_per_byte;
- tdep->bytes_per_address = binfo->bits_per_address / binfo->bits_per_byte;
- gdbarch = gdbarch_alloc (&info, tdep);
- /* Target data types */
- set_gdbarch_short_bit (gdbarch, 16);
- set_gdbarch_int_bit (gdbarch, 32);
- set_gdbarch_long_bit (gdbarch, 32);
- set_gdbarch_long_long_bit (gdbarch, 64);
- set_gdbarch_float_bit (gdbarch, 32);
- set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
- set_gdbarch_double_bit (gdbarch, 64);
- set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
- set_gdbarch_long_double_bit (gdbarch, 64);
- set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
- set_gdbarch_ptr_bit (gdbarch, binfo->bits_per_address);
- set_gdbarch_addr_bit (gdbarch, binfo->bits_per_address);
- set_gdbarch_char_signed (gdbarch, 1);
- /* Information about the target architecture */
- set_gdbarch_return_value (gdbarch, or1k_return_value);
- set_gdbarch_breakpoint_kind_from_pc (gdbarch,
- or1k_breakpoint::kind_from_pc);
- set_gdbarch_sw_breakpoint_from_kind (gdbarch,
- or1k_breakpoint::bp_from_kind);
- set_gdbarch_have_nonsteppable_watchpoint (gdbarch, 1);
- /* Register architecture */
- set_gdbarch_num_regs (gdbarch, OR1K_NUM_REGS);
- set_gdbarch_num_pseudo_regs (gdbarch, OR1K_NUM_PSEUDO_REGS);
- set_gdbarch_sp_regnum (gdbarch, OR1K_SP_REGNUM);
- set_gdbarch_pc_regnum (gdbarch, OR1K_NPC_REGNUM);
- set_gdbarch_ps_regnum (gdbarch, OR1K_SR_REGNUM);
- set_gdbarch_deprecated_fp_regnum (gdbarch, OR1K_FP_REGNUM);
- /* Functions to analyse frames */
- set_gdbarch_skip_prologue (gdbarch, or1k_skip_prologue);
- set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
- set_gdbarch_frame_align (gdbarch, or1k_frame_align);
- set_gdbarch_frame_red_zone_size (gdbarch, OR1K_FRAME_RED_ZONE_SIZE);
- /* Functions to access frame data */
- set_gdbarch_unwind_pc (gdbarch, or1k_unwind_pc);
- set_gdbarch_unwind_sp (gdbarch, or1k_unwind_sp);
- /* Functions handling dummy frames */
- set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
- set_gdbarch_push_dummy_code (gdbarch, or1k_push_dummy_code);
- set_gdbarch_push_dummy_call (gdbarch, or1k_push_dummy_call);
- /* Frame unwinders. Use DWARF debug info if available, otherwise use our
- own unwinder. */
- dwarf2_append_unwinders (gdbarch);
- frame_unwind_append_unwinder (gdbarch, &or1k_frame_unwind);
- /* Get a CGEN CPU descriptor for this architecture. */
- {
- const char *mach_name = binfo->printable_name;
- enum cgen_endian endian = (info.byte_order == BFD_ENDIAN_BIG
- ? CGEN_ENDIAN_BIG : CGEN_ENDIAN_LITTLE);
- tdep->gdb_cgen_cpu_desc =
- or1k_cgen_cpu_open (CGEN_CPU_OPEN_BFDMACH, mach_name,
- CGEN_CPU_OPEN_ENDIAN, endian, CGEN_CPU_OPEN_END);
- or1k_cgen_init_asm (tdep->gdb_cgen_cpu_desc);
- }
- /* If this mach has a delay slot. */
- if (binfo->mach == bfd_mach_or1k)
- set_gdbarch_single_step_through_delay (gdbarch,
- or1k_single_step_through_delay);
- if (!tdesc_has_registers (info.target_desc))
- /* Pick a default target description. */
- tdesc = tdesc_or1k;
- /* Check any target description for validity. */
- if (tdesc_has_registers (tdesc))
- {
- const struct tdesc_feature *feature;
- int valid_p;
- int i;
- feature = tdesc_find_feature (tdesc, "org.gnu.gdb.or1k.group0");
- if (feature == NULL)
- return NULL;
- tdesc_data = tdesc_data_alloc ();
- valid_p = 1;
- for (i = 0; i < OR1K_NUM_REGS; i++)
- valid_p &= tdesc_numbered_register (feature, tdesc_data.get (), i,
- or1k_reg_names[i]);
- if (!valid_p)
- return NULL;
- }
- if (tdesc_data != NULL)
- tdesc_use_registers (gdbarch, tdesc, std::move (tdesc_data));
- /* Hook in ABI-specific overrides, if they have been registered. */
- gdbarch_init_osabi (info, gdbarch);
- return gdbarch;
- }
- /* Dump the target specific data for this architecture. */
- static void
- or1k_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file)
- {
- or1k_gdbarch_tdep *tdep = (or1k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- if (NULL == tdep)
- return; /* Nothing to report */
- gdb_printf (file, "or1k_dump_tdep: %d bytes per word\n",
- tdep->bytes_per_word);
- gdb_printf (file, "or1k_dump_tdep: %d bytes per address\n",
- tdep->bytes_per_address);
- }
- void _initialize_or1k_tdep ();
- void
- _initialize_or1k_tdep ()
- {
- /* Register this architecture. */
- gdbarch_register (bfd_arch_or1k, or1k_gdbarch_init, or1k_dump_tdep);
- initialize_tdesc_or1k ();
- /* Debugging flag. */
- add_setshow_boolean_cmd ("or1k", class_maintenance, &or1k_debug,
- _("Set OpenRISC debugging."),
- _("Show OpenRISC debugging."),
- _("When on, OpenRISC specific debugging is enabled."),
- NULL,
- show_or1k_debug,
- &setdebuglist, &showdebuglist);
- }
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