368 lines
14 KiB
C
368 lines
14 KiB
C
/* Definitions to make GDB run on a vax under 4.2bsd.
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Copyright (C) 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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/* There is one known bug with VAX support that I don't know how to
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fix: if you do a backtrace from a signal handler, you get something
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like:
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#0 0xbc in kill (592, 3)
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#1 0x7f in hand (...) (...)
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#2 0x7fffec7e in ?? (2, 0, 2147478112, 94)
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^^ GDB doesn't know about sigtramp
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#3 0x7fffec70 in ?? (592, 2)
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^^^^^^^^^^ wrong address
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#4 0xae in main (...) (...)
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when the correct backtrace (as given by adb) is:
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_kill(250,3) from _hand+21
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_hand(2,0,7fffea60,5e) from 7fffec7e
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sigtramp(2,0,7fffea60,5e) from _kill+4
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_kill(250,2) from _main+2e
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_main(1,7fffeac4,7fffeacc) from start+3d
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If anyone knows enough about VAX BSD to fix this, please send the
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fix to bug-gdb@prep.ai.mit.edu. */
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#define TARGET_BYTE_ORDER LITTLE_ENDIAN
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/* Define this if the C compiler puts an underscore at the front
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of external names before giving them to the linker. */
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#define NAMES_HAVE_UNDERSCORE
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/* Offset from address of function to start of its code.
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Zero on most machines. */
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#define FUNCTION_START_OFFSET 2
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/* Advance PC across any function entry prologue instructions
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to reach some "real" code. */
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#define SKIP_PROLOGUE(pc) \
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{ register int op = (unsigned char) read_memory_integer (pc, 1); \
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if (op == 0x11) pc += 2; /* skip brb */ \
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if (op == 0x31) pc += 3; /* skip brw */ \
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if (op == 0xC2 && \
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((unsigned char) read_memory_integer (pc+2, 1)) == 0x5E) \
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pc += 3; /* skip subl2 */ \
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if (op == 0x9E && \
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((unsigned char) read_memory_integer (pc+1, 1)) == 0xAE && \
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((unsigned char) read_memory_integer(pc+3, 1)) == 0x5E) \
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pc += 4; /* skip movab */ \
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if (op == 0x9E && \
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((unsigned char) read_memory_integer (pc+1, 1)) == 0xCE && \
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((unsigned char) read_memory_integer(pc+4, 1)) == 0x5E) \
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pc += 5; /* skip movab */ \
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if (op == 0x9E && \
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((unsigned char) read_memory_integer (pc+1, 1)) == 0xEE && \
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((unsigned char) read_memory_integer(pc+6, 1)) == 0x5E) \
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pc += 7; /* skip movab */ \
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}
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/* Immediately after a function call, return the saved pc.
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Can't always go through the frames for this because on some machines
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the new frame is not set up until the new function executes
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some instructions. */
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#define SAVED_PC_AFTER_CALL(frame) FRAME_SAVED_PC(frame)
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#define TARGET_UPAGES 10
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#define TARGET_NBPG 512
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#define STACK_END_ADDR (0x80000000 - (TARGET_UPAGES * TARGET_NBPG))
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/* On the VAX, sigtramp is in the u area. Can't check the exact
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addresses because for cross-debugging we don't have VAX include
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files around. This should be close enough. */
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#define IN_SIGTRAMP(pc, name) ((pc) >= STACK_END_ADDR && (pc < 0x80000000))
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/* Stack grows downward. */
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#define INNER_THAN <
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/* Sequence of bytes for breakpoint instruction. */
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#define BREAKPOINT {3}
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/* Amount PC must be decremented by after a breakpoint.
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This is often the number of bytes in BREAKPOINT
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but not always. */
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#define DECR_PC_AFTER_BREAK 0
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/* Nonzero if instruction at PC is a return instruction. */
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#define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 1) == 04)
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/* Return 1 if P points to an invalid floating point value.
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LEN is the length in bytes -- not relevant on the Vax. */
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#define INVALID_FLOAT(p, len) ((*(short *) p & 0xff80) == 0x8000)
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/* Say how long (ordinary) registers are. */
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#define REGISTER_TYPE long
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/* Number of machine registers */
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#define NUM_REGS 17
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/* Initializer for an array of names of registers.
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There should be NUM_REGS strings in this initializer. */
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#define REGISTER_NAMES {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc", "ps"}
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/* Register numbers of various important registers.
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Note that some of these values are "real" register numbers,
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and correspond to the general registers of the machine,
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and some are "phony" register numbers which are too large
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to be actual register numbers as far as the user is concerned
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but do serve to get the desired values when passed to read_register. */
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#define AP_REGNUM 12
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#define FP_REGNUM 13 /* Contains address of executing stack frame */
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#define SP_REGNUM 14 /* Contains address of top of stack */
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#define PC_REGNUM 15 /* Contains program counter */
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#define PS_REGNUM 16 /* Contains processor status */
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/* Total amount of space needed to store our copies of the machine's
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register state, the array `registers'. */
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#define REGISTER_BYTES (17*4)
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/* Index within `registers' of the first byte of the space for
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register N. */
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#define REGISTER_BYTE(N) ((N) * 4)
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/* Number of bytes of storage in the actual machine representation
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for register N. On the vax, all regs are 4 bytes. */
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#define REGISTER_RAW_SIZE(N) 4
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/* Number of bytes of storage in the program's representation
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for register N. On the vax, all regs are 4 bytes. */
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#define REGISTER_VIRTUAL_SIZE(N) 4
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/* Largest value REGISTER_RAW_SIZE can have. */
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#define MAX_REGISTER_RAW_SIZE 4
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/* Largest value REGISTER_VIRTUAL_SIZE can have. */
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#define MAX_REGISTER_VIRTUAL_SIZE 4
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/* Nonzero if register N requires conversion
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from raw format to virtual format. */
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#define REGISTER_CONVERTIBLE(N) 0
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/* Convert data from raw format for register REGNUM
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to virtual format for register REGNUM. */
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#define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
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bcopy ((FROM), (TO), 4);
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/* Convert data from virtual format for register REGNUM
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to raw format for register REGNUM. */
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#define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
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bcopy ((FROM), (TO), 4);
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/* Return the GDB type object for the "standard" data type
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of data in register N. */
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#define REGISTER_VIRTUAL_TYPE(N) builtin_type_int
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/* Store the address of the place in which to copy the structure the
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subroutine will return. This is called from call_function. */
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#define STORE_STRUCT_RETURN(ADDR, SP) \
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{ write_register (1, (ADDR)); }
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/* Extract from an array REGBUF containing the (raw) register state
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a function return value of type TYPE, and copy that, in virtual format,
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into VALBUF. */
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#define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
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bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE))
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/* Write into appropriate registers a function return value
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of type TYPE, given in virtual format. */
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#define STORE_RETURN_VALUE(TYPE,VALBUF) \
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write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
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/* Extract from an array REGBUF containing the (raw) register state
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the address in which a function should return its structure value,
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as a CORE_ADDR (or an expression that can be used as one). */
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#define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
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/* Describe the pointer in each stack frame to the previous stack frame
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(its caller). */
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/* FRAME_CHAIN takes a frame's nominal address
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and produces the frame's chain-pointer.
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However, if FRAME_CHAIN_VALID returns zero,
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it means the given frame is the outermost one and has no caller. */
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/* In the case of the Vax, the frame's nominal address is the FP value,
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and 12 bytes later comes the saved previous FP value as a 4-byte word. */
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#define FRAME_CHAIN(thisframe) \
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(outside_startup_file ((thisframe)->pc) ? \
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read_memory_integer ((thisframe)->frame + 12, 4) :\
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0)
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#define FRAME_CHAIN_VALID(chain, thisframe) \
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(chain != 0 && (outside_startup_file (FRAME_SAVED_PC (thisframe))))
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/* Define other aspects of the stack frame. */
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/* A macro that tells us whether the function invocation represented
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by FI does not have a frame on the stack associated with it. If it
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does not, FRAMELESS is set to 1, else 0. */
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/* On the vax, all functions have frames. */
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#define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) {(FRAMELESS) = 0;}
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/* Saved Pc. */
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#define FRAME_SAVED_PC(FRAME) (read_memory_integer ((FRAME)->frame + 16, 4))
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/* Cannot find the AP register value directly from the FP value. Must
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find it saved in the frame called by this one, or in the AP
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register for the innermost frame. However, there is no way to tell
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the difference between the innermost frame and a frame for which we
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just don't know the frame that it called (e.g. "info frame
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0x7ffec789"). For the sake of argument suppose that the stack is
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somewhat trashed (which is one reason that "info frame" exists).
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So return 0 (indicating we don't know the address of
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the arglist) if we don't know what frame this frame calls. */
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#define FRAME_ARGS_ADDRESS_CORRECT(fi) \
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(((fi)->next_frame \
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? read_memory_integer ((fi)->next_frame + 8, 4) \
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: /* read_register (AP_REGNUM) */ 0))
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/* In most of GDB, getting the args address is too important to
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just say "I don't know". This is sometimes wrong for functions
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that aren't on top of the stack, but c'est la vie. */
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#define FRAME_ARGS_ADDRESS(fi) \
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(((fi)->next_frame \
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? read_memory_integer ((fi)->next_frame + 8, 4) \
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: read_register (AP_REGNUM) /* 0 */))
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#define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
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/* Return number of args passed to a frame.
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Can return -1, meaning no way to tell. */
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#define FRAME_NUM_ARGS(numargs, fi) \
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{ numargs = (0xff & read_memory_integer (FRAME_ARGS_ADDRESS (fi), 1)); }
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/* Return number of bytes at start of arglist that are not really args. */
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#define FRAME_ARGS_SKIP 4
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/* Put here the code to store, into a struct frame_saved_regs,
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the addresses of the saved registers of frame described by FRAME_INFO.
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This includes special registers such as pc and fp saved in special
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ways in the stack frame. sp is even more special:
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the address we return for it IS the sp for the next frame. */
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#define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
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{ register int regnum; \
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register int regmask = read_memory_integer ((frame_info)->frame+4, 4) >> 16; \
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register CORE_ADDR next_addr; \
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bzero (&frame_saved_regs, sizeof frame_saved_regs); \
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next_addr = (frame_info)->frame + 16; \
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/* Regmask's low bit is for register 0, \
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which is the first one that would be pushed. */ \
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for (regnum = 0; regnum < 12; regnum++, regmask >>= 1) \
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(frame_saved_regs).regs[regnum] = (regmask & 1) ? (next_addr += 4) : 0; \
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(frame_saved_regs).regs[SP_REGNUM] = next_addr + 4; \
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if (read_memory_integer ((frame_info)->frame + 4, 4) & 0x20000000) \
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(frame_saved_regs).regs[SP_REGNUM] += 4 + 4 * read_memory_integer (next_addr + 4, 4); \
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(frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 16; \
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(frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame + 12; \
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(frame_saved_regs).regs[AP_REGNUM] = (frame_info)->frame + 8; \
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(frame_saved_regs).regs[PS_REGNUM] = (frame_info)->frame + 4; \
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}
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/* Things needed for making the inferior call functions. */
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/* Push an empty stack frame, to record the current PC, etc. */
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#define PUSH_DUMMY_FRAME \
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{ register CORE_ADDR sp = read_register (SP_REGNUM);\
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register int regnum; \
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sp = push_word (sp, 0); /* arglist */ \
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for (regnum = 11; regnum >= 0; regnum--) \
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sp = push_word (sp, read_register (regnum)); \
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sp = push_word (sp, read_register (PC_REGNUM)); \
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sp = push_word (sp, read_register (FP_REGNUM)); \
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sp = push_word (sp, read_register (AP_REGNUM)); \
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sp = push_word (sp, (read_register (PS_REGNUM) & 0xffef) \
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+ 0x2fff0000); \
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sp = push_word (sp, 0); \
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write_register (SP_REGNUM, sp); \
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write_register (FP_REGNUM, sp); \
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write_register (AP_REGNUM, sp + 17 * sizeof (int)); }
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/* Discard from the stack the innermost frame, restoring all registers. */
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#define POP_FRAME \
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{ register CORE_ADDR fp = read_register (FP_REGNUM); \
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register int regnum; \
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register int regmask = read_memory_integer (fp + 4, 4); \
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write_register (PS_REGNUM, \
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(regmask & 0xffff) \
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| (read_register (PS_REGNUM) & 0xffff0000)); \
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write_register (PC_REGNUM, read_memory_integer (fp + 16, 4)); \
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write_register (FP_REGNUM, read_memory_integer (fp + 12, 4)); \
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write_register (AP_REGNUM, read_memory_integer (fp + 8, 4)); \
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fp += 16; \
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for (regnum = 0; regnum < 12; regnum++) \
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if (regmask & (0x10000 << regnum)) \
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write_register (regnum, read_memory_integer (fp += 4, 4)); \
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fp = fp + 4 + ((regmask >> 30) & 3); \
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if (regmask & 0x20000000) \
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{ regnum = read_memory_integer (fp, 4); \
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fp += (regnum + 1) * 4; } \
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write_register (SP_REGNUM, fp); \
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flush_cached_frames (); \
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set_current_frame (create_new_frame (read_register (FP_REGNUM),\
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read_pc ())); }
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/* This sequence of words is the instructions
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calls #69, @#32323232
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bpt
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Note this is 8 bytes. */
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#define CALL_DUMMY {0x329f69fb, 0x03323232}
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#define CALL_DUMMY_START_OFFSET 0 /* Start execution at beginning of dummy */
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/* Insert the specified number of args and function address
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into a call sequence of the above form stored at DUMMYNAME. */
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#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
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{ *((char *) dummyname + 1) = nargs; \
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*(int *)((char *) dummyname + 3) = fun; }
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