| /* Target-machine dependent code for the AMD 29000 |
| Copyright 1990, 1991, 1992, 1993, 1994, 1995 |
| Free Software Foundation, Inc. |
| Contributed by Cygnus Support. Written by Jim Kingdon. |
| |
| 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. */ |
| |
| #include "defs.h" |
| #include "gdbcore.h" |
| #include "frame.h" |
| #include "value.h" |
| #include "symtab.h" |
| #include "inferior.h" |
| #include "gdbcmd.h" |
| |
| /* If all these bits in an instruction word are zero, it is a "tag word" |
| which precedes a function entry point and gives stack traceback info. |
| This used to be defined as 0xff000000, but that treated 0x00000deb as |
| a tag word, while it is really used as a breakpoint. */ |
| #define TAGWORD_ZERO_MASK 0xff00f800 |
| |
| extern CORE_ADDR text_start; /* FIXME, kludge... */ |
| |
| /* The user-settable top of the register stack in virtual memory. We |
| won't attempt to access any stored registers above this address, if set |
| nonzero. */ |
| |
| static CORE_ADDR rstack_high_address = UINT_MAX; |
| |
| |
| /* Should call_function allocate stack space for a struct return? */ |
| /* On the a29k objects over 16 words require the caller to allocate space. */ |
| int |
| a29k_use_struct_convention (gcc_p, type) |
| int gcc_p; |
| struct type *type; |
| { |
| return (TYPE_LENGTH (type) > 16 * 4); |
| } |
| |
| |
| /* Structure to hold cached info about function prologues. */ |
| |
| struct prologue_info |
| { |
| CORE_ADDR pc; /* First addr after fn prologue */ |
| unsigned rsize, msize; /* register stack frame size, mem stack ditto */ |
| unsigned mfp_used:1; /* memory frame pointer used */ |
| unsigned rsize_valid:1; /* Validity bits for the above */ |
| unsigned msize_valid:1; |
| unsigned mfp_valid:1; |
| }; |
| |
| /* Examine the prologue of a function which starts at PC. Return |
| the first addess past the prologue. If MSIZE is non-NULL, then |
| set *MSIZE to the memory stack frame size. If RSIZE is non-NULL, |
| then set *RSIZE to the register stack frame size (not including |
| incoming arguments and the return address & frame pointer stored |
| with them). If no prologue is found, *RSIZE is set to zero. |
| If no prologue is found, or a prologue which doesn't involve |
| allocating a memory stack frame, then set *MSIZE to zero. |
| |
| Note that both msize and rsize are in bytes. This is not consistent |
| with the _User's Manual_ with respect to rsize, but it is much more |
| convenient. |
| |
| If MFP_USED is non-NULL, *MFP_USED is set to nonzero if a memory |
| frame pointer is being used. */ |
| |
| CORE_ADDR |
| examine_prologue (pc, rsize, msize, mfp_used) |
| CORE_ADDR pc; |
| unsigned *msize; |
| unsigned *rsize; |
| int *mfp_used; |
| { |
| long insn; |
| CORE_ADDR p = pc; |
| struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc); |
| struct prologue_info *mi = 0; |
| |
| if (msymbol != NULL) |
| mi = (struct prologue_info *) msymbol->info; |
| |
| if (mi != 0) |
| { |
| int valid = 1; |
| if (rsize != NULL) |
| { |
| *rsize = mi->rsize; |
| valid &= mi->rsize_valid; |
| } |
| if (msize != NULL) |
| { |
| *msize = mi->msize; |
| valid &= mi->msize_valid; |
| } |
| if (mfp_used != NULL) |
| { |
| *mfp_used = mi->mfp_used; |
| valid &= mi->mfp_valid; |
| } |
| if (valid) |
| return mi->pc; |
| } |
| |
| if (rsize != NULL) |
| *rsize = 0; |
| if (msize != NULL) |
| *msize = 0; |
| if (mfp_used != NULL) |
| *mfp_used = 0; |
| |
| /* Prologue must start with subtracting a constant from gr1. |
| Normally this is sub gr1,gr1,<rsize * 4>. */ |
| insn = read_memory_integer (p, 4); |
| if ((insn & 0xffffff00) != 0x25010100) |
| { |
| /* If the frame is large, instead of a single instruction it |
| might be a pair of instructions: |
| const <reg>, <rsize * 4> |
| sub gr1,gr1,<reg> |
| */ |
| int reg; |
| /* Possible value for rsize. */ |
| unsigned int rsize0; |
| |
| if ((insn & 0xff000000) != 0x03000000) |
| { |
| p = pc; |
| goto done; |
| } |
| reg = (insn >> 8) & 0xff; |
| rsize0 = (((insn >> 8) & 0xff00) | (insn & 0xff)); |
| p += 4; |
| insn = read_memory_integer (p, 4); |
| if ((insn & 0xffffff00) != 0x24010100 |
| || (insn & 0xff) != reg) |
| { |
| p = pc; |
| goto done; |
| } |
| if (rsize != NULL) |
| *rsize = rsize0; |
| } |
| else |
| { |
| if (rsize != NULL) |
| *rsize = (insn & 0xff); |
| } |
| p += 4; |
| |
| /* Next instruction ought to be asgeu V_SPILL,gr1,rab. |
| * We don't check the vector number to allow for kernel debugging. The |
| * kernel will use a different trap number. |
| * If this insn is missing, we just keep going; Metaware R2.3u compiler |
| * generates prologue that intermixes initializations and puts the asgeu |
| * way down. |
| */ |
| insn = read_memory_integer (p, 4); |
| if ((insn & 0xff00ffff) == (0x5e000100 | RAB_HW_REGNUM)) |
| { |
| p += 4; |
| } |
| |
| /* Next instruction usually sets the frame pointer (lr1) by adding |
| <size * 4> from gr1. However, this can (and high C does) be |
| deferred until anytime before the first function call. So it is |
| OK if we don't see anything which sets lr1. |
| To allow for alternate register sets (gcc -mkernel-registers) the msp |
| register number is a compile time constant. */ |
| |
| /* Normally this is just add lr1,gr1,<size * 4>. */ |
| insn = read_memory_integer (p, 4); |
| if ((insn & 0xffffff00) == 0x15810100) |
| p += 4; |
| else |
| { |
| /* However, for large frames it can be |
| const <reg>, <size *4> |
| add lr1,gr1,<reg> |
| */ |
| int reg; |
| CORE_ADDR q; |
| |
| if ((insn & 0xff000000) == 0x03000000) |
| { |
| reg = (insn >> 8) & 0xff; |
| q = p + 4; |
| insn = read_memory_integer (q, 4); |
| if ((insn & 0xffffff00) == 0x14810100 |
| && (insn & 0xff) == reg) |
| p = q; |
| } |
| } |
| |
| /* Next comes "add lr{<rsize-1>},msp,0", but only if a memory |
| frame pointer is in use. We just check for add lr<anything>,msp,0; |
| we don't check this rsize against the first instruction, and |
| we don't check that the trace-back tag indicates a memory frame pointer |
| is in use. |
| To allow for alternate register sets (gcc -mkernel-registers) the msp |
| register number is a compile time constant. |
| |
| The recommended instruction is actually "sll lr<whatever>,msp,0". |
| We check for that, too. Originally Jim Kingdon's code seemed |
| to be looking for a "sub" instruction here, but the mask was set |
| up to lose all the time. */ |
| insn = read_memory_integer (p, 4); |
| if (((insn & 0xff80ffff) == (0x15800000 | (MSP_HW_REGNUM << 8))) /* add */ |
| || ((insn & 0xff80ffff) == (0x81800000 | (MSP_HW_REGNUM << 8)))) /* sll */ |
| { |
| p += 4; |
| if (mfp_used != NULL) |
| *mfp_used = 1; |
| } |
| |
| /* Next comes a subtraction from msp to allocate a memory frame, |
| but only if a memory frame is |
| being used. We don't check msize against the trace-back tag. |
| |
| To allow for alternate register sets (gcc -mkernel-registers) the msp |
| register number is a compile time constant. |
| |
| Normally this is just |
| sub msp,msp,<msize> |
| */ |
| insn = read_memory_integer (p, 4); |
| if ((insn & 0xffffff00) == |
| (0x25000000 | (MSP_HW_REGNUM << 16) | (MSP_HW_REGNUM << 8))) |
| { |
| p += 4; |
| if (msize != NULL) |
| *msize = insn & 0xff; |
| } |
| else |
| { |
| /* For large frames, instead of a single instruction it might |
| be |
| |
| const <reg>, <msize> |
| consth <reg>, <msize> ; optional |
| sub msp,msp,<reg> |
| */ |
| int reg; |
| unsigned msize0; |
| CORE_ADDR q = p; |
| |
| if ((insn & 0xff000000) == 0x03000000) |
| { |
| reg = (insn >> 8) & 0xff; |
| msize0 = ((insn >> 8) & 0xff00) | (insn & 0xff); |
| q += 4; |
| insn = read_memory_integer (q, 4); |
| /* Check for consth. */ |
| if ((insn & 0xff000000) == 0x02000000 |
| && (insn & 0x0000ff00) == reg) |
| { |
| msize0 |= (insn << 8) & 0xff000000; |
| msize0 |= (insn << 16) & 0x00ff0000; |
| q += 4; |
| insn = read_memory_integer (q, 4); |
| } |
| /* Check for sub msp,msp,<reg>. */ |
| if ((insn & 0xffffff00) == |
| (0x24000000 | (MSP_HW_REGNUM << 16) | (MSP_HW_REGNUM << 8)) |
| && (insn & 0xff) == reg) |
| { |
| p = q + 4; |
| if (msize != NULL) |
| *msize = msize0; |
| } |
| } |
| } |
| |
| /* Next instruction might be asgeu V_SPILL,gr1,rab. |
| * We don't check the vector number to allow for kernel debugging. The |
| * kernel will use a different trap number. |
| * Metaware R2.3u compiler |
| * generates prologue that intermixes initializations and puts the asgeu |
| * way down after everything else. |
| */ |
| insn = read_memory_integer (p, 4); |
| if ((insn & 0xff00ffff) == (0x5e000100 | RAB_HW_REGNUM)) |
| { |
| p += 4; |
| } |
| |
| done: |
| if (msymbol != NULL) |
| { |
| if (mi == 0) |
| { |
| /* Add a new cache entry. */ |
| mi = (struct prologue_info *) xmalloc (sizeof (struct prologue_info)); |
| msymbol->info = (char *) mi; |
| mi->rsize_valid = 0; |
| mi->msize_valid = 0; |
| mi->mfp_valid = 0; |
| } |
| /* else, cache entry exists, but info is incomplete. */ |
| mi->pc = p; |
| if (rsize != NULL) |
| { |
| mi->rsize = *rsize; |
| mi->rsize_valid = 1; |
| } |
| if (msize != NULL) |
| { |
| mi->msize = *msize; |
| mi->msize_valid = 1; |
| } |
| if (mfp_used != NULL) |
| { |
| mi->mfp_used = *mfp_used; |
| mi->mfp_valid = 1; |
| } |
| } |
| return p; |
| } |
| |
| /* Advance PC across any function entry prologue instructions |
| to reach some "real" code. */ |
| |
| CORE_ADDR |
| a29k_skip_prologue (pc) |
| CORE_ADDR pc; |
| { |
| return examine_prologue (pc, NULL, NULL, NULL); |
| } |
| |
| /* |
| * Examine the one or two word tag at the beginning of a function. |
| * The tag word is expect to be at 'p', if it is not there, we fail |
| * by returning 0. The documentation for the tag word was taken from |
| * page 7-15 of the 29050 User's Manual. We are assuming that the |
| * m bit is in bit 22 of the tag word, which seems to be the agreed upon |
| * convention today (1/15/92). |
| * msize is return in bytes. |
| */ |
| |
| static int /* 0/1 - failure/success of finding the tag word */ |
| examine_tag (p, is_trans, argcount, msize, mfp_used) |
| CORE_ADDR p; |
| int *is_trans; |
| int *argcount; |
| unsigned *msize; |
| int *mfp_used; |
| { |
| unsigned int tag1, tag2; |
| |
| tag1 = read_memory_integer (p, 4); |
| if ((tag1 & TAGWORD_ZERO_MASK) != 0) /* Not a tag word */ |
| return 0; |
| if (tag1 & (1 << 23)) /* A two word tag */ |
| { |
| tag2 = read_memory_integer (p - 4, 4); |
| if (msize) |
| *msize = tag2 * 2; |
| } |
| else |
| /* A one word tag */ |
| { |
| if (msize) |
| *msize = tag1 & 0x7ff; |
| } |
| if (is_trans) |
| *is_trans = ((tag1 & (1 << 21)) ? 1 : 0); |
| /* Note that this includes the frame pointer and the return address |
| register, so the actual number of registers of arguments is two less. |
| argcount can be zero, however, sometimes, for strange assembler |
| routines. */ |
| if (argcount) |
| *argcount = (tag1 >> 16) & 0x1f; |
| if (mfp_used) |
| *mfp_used = ((tag1 & (1 << 22)) ? 1 : 0); |
| return 1; |
| } |
| |
| /* Initialize the frame. In addition to setting "extra" frame info, |
| we also set ->frame because we use it in a nonstandard way, and ->pc |
| because we need to know it to get the other stuff. See the diagram |
| of stacks and the frame cache in tm-a29k.h for more detail. */ |
| |
| static void |
| init_frame_info (innermost_frame, frame) |
| int innermost_frame; |
| struct frame_info *frame; |
| { |
| CORE_ADDR p; |
| long insn; |
| unsigned rsize; |
| unsigned msize; |
| int mfp_used, trans; |
| struct symbol *func; |
| |
| p = frame->pc; |
| |
| if (innermost_frame) |
| frame->frame = read_register (GR1_REGNUM); |
| else |
| frame->frame = frame->next->frame + frame->next->rsize; |
| |
| #if 0 /* CALL_DUMMY_LOCATION == ON_STACK */ |
| This wont work; |
| #else |
| if (PC_IN_CALL_DUMMY (p, 0, 0)) |
| #endif |
| { |
| frame->rsize = DUMMY_FRAME_RSIZE; |
| /* This doesn't matter since we never try to get locals or args |
| from a dummy frame. */ |
| frame->msize = 0; |
| /* Dummy frames always use a memory frame pointer. */ |
| frame->saved_msp = |
| read_register_stack_integer (frame->frame + DUMMY_FRAME_RSIZE - 4, 4); |
| frame->flags |= (TRANSPARENT_FRAME | MFP_USED); |
| return; |
| } |
| |
| func = find_pc_function (p); |
| if (func != NULL) |
| p = BLOCK_START (SYMBOL_BLOCK_VALUE (func)); |
| else |
| { |
| /* Search backward to find the trace-back tag. However, |
| do not trace back beyond the start of the text segment |
| (just as a sanity check to avoid going into never-never land). */ |
| #if 1 |
| while (p >= text_start |
| && ((insn = read_memory_integer (p, 4)) & TAGWORD_ZERO_MASK) != 0) |
| p -= 4; |
| #else /* 0 */ |
| char pat[4] = |
| {0, 0, 0, 0}; |
| char mask[4]; |
| char insn_raw[4]; |
| store_unsigned_integer (mask, 4, TAGWORD_ZERO_MASK); |
| /* Enable this once target_search is enabled and tested. */ |
| target_search (4, pat, mask, p, -4, text_start, p + 1, &p, &insn_raw); |
| insn = extract_unsigned_integer (insn_raw, 4); |
| #endif /* 0 */ |
| |
| if (p < text_start) |
| { |
| /* Couldn't find the trace-back tag. |
| Something strange is going on. */ |
| frame->saved_msp = 0; |
| frame->rsize = 0; |
| frame->msize = 0; |
| frame->flags = TRANSPARENT_FRAME; |
| return; |
| } |
| else |
| /* Advance to the first word of the function, i.e. the word |
| after the trace-back tag. */ |
| p += 4; |
| } |
| |
| /* We've found the start of the function. |
| Try looking for a tag word that indicates whether there is a |
| memory frame pointer and what the memory stack allocation is. |
| If one doesn't exist, try using a more exhaustive search of |
| the prologue. */ |
| |
| if (examine_tag (p - 4, &trans, (int *) NULL, &msize, &mfp_used)) /* Found good tag */ |
| examine_prologue (p, &rsize, 0, 0); |
| else /* No tag try prologue */ |
| examine_prologue (p, &rsize, &msize, &mfp_used); |
| |
| frame->rsize = rsize; |
| frame->msize = msize; |
| frame->flags = 0; |
| if (mfp_used) |
| frame->flags |= MFP_USED; |
| if (trans) |
| frame->flags |= TRANSPARENT_FRAME; |
| if (innermost_frame) |
| { |
| frame->saved_msp = read_register (MSP_REGNUM) + msize; |
| } |
| else |
| { |
| if (mfp_used) |
| frame->saved_msp = |
| read_register_stack_integer (frame->frame + rsize - 4, 4); |
| else |
| frame->saved_msp = frame->next->saved_msp + msize; |
| } |
| } |
| |
| void |
| init_extra_frame_info (frame) |
| struct frame_info *frame; |
| { |
| if (frame->next == 0) |
| /* Assume innermost frame. May produce strange results for "info frame" |
| but there isn't any way to tell the difference. */ |
| init_frame_info (1, frame); |
| else |
| { |
| /* We're in get_prev_frame. |
| Take care of everything in init_frame_pc. */ |
| ; |
| } |
| } |
| |
| void |
| init_frame_pc (fromleaf, frame) |
| int fromleaf; |
| struct frame_info *frame; |
| { |
| frame->pc = (fromleaf ? SAVED_PC_AFTER_CALL (frame->next) : |
| frame->next ? FRAME_SAVED_PC (frame->next) : read_pc ()); |
| init_frame_info (fromleaf, frame); |
| } |
| |
| /* Local variables (i.e. LOC_LOCAL) are on the memory stack, with their |
| offsets being relative to the memory stack pointer (high C) or |
| saved_msp (gcc). */ |
| |
| CORE_ADDR |
| frame_locals_address (fi) |
| struct frame_info *fi; |
| { |
| if (fi->flags & MFP_USED) |
| return fi->saved_msp; |
| else |
| return fi->saved_msp - fi->msize; |
| } |
| |
| /* Routines for reading the register stack. The caller gets to treat |
| the register stack as a uniform stack in memory, from address $gr1 |
| straight through $rfb and beyond. */ |
| |
| /* Analogous to read_memory except the length is understood to be 4. |
| Also, myaddr can be NULL (meaning don't bother to read), and |
| if actual_mem_addr is non-NULL, store there the address that it |
| was fetched from (or if from a register the offset within |
| registers). Set *LVAL to lval_memory or lval_register, depending |
| on where it came from. The contents written into MYADDR are in |
| target format. */ |
| void |
| read_register_stack (memaddr, myaddr, actual_mem_addr, lval) |
| CORE_ADDR memaddr; |
| char *myaddr; |
| CORE_ADDR *actual_mem_addr; |
| enum lval_type *lval; |
| { |
| long rfb = read_register (RFB_REGNUM); |
| long rsp = read_register (RSP_REGNUM); |
| |
| /* If we don't do this 'info register' stops in the middle. */ |
| if (memaddr >= rstack_high_address) |
| { |
| /* a bogus value */ |
| static char val[] = |
| {~0, ~0, ~0, ~0}; |
| /* It's in a local register, but off the end of the stack. */ |
| int regnum = (memaddr - rsp) / 4 + LR0_REGNUM; |
| if (myaddr != NULL) |
| { |
| /* Provide bogusness */ |
| memcpy (myaddr, val, 4); |
| } |
| supply_register (regnum, val); /* More bogusness */ |
| if (lval != NULL) |
| *lval = lval_register; |
| if (actual_mem_addr != NULL) |
| *actual_mem_addr = REGISTER_BYTE (regnum); |
| } |
| /* If it's in the part of the register stack that's in real registers, |
| get the value from the registers. If it's anywhere else in memory |
| (e.g. in another thread's saved stack), skip this part and get |
| it from real live memory. */ |
| else if (memaddr < rfb && memaddr >= rsp) |
| { |
| /* It's in a register. */ |
| int regnum = (memaddr - rsp) / 4 + LR0_REGNUM; |
| if (regnum > LR0_REGNUM + 127) |
| error ("Attempt to read register stack out of range."); |
| if (myaddr != NULL) |
| read_register_gen (regnum, myaddr); |
| if (lval != NULL) |
| *lval = lval_register; |
| if (actual_mem_addr != NULL) |
| *actual_mem_addr = REGISTER_BYTE (regnum); |
| } |
| else |
| { |
| /* It's in the memory portion of the register stack. */ |
| if (myaddr != NULL) |
| read_memory (memaddr, myaddr, 4); |
| if (lval != NULL) |
| *lval = lval_memory; |
| if (actual_mem_addr != NULL) |
| *actual_mem_addr = memaddr; |
| } |
| } |
| |
| /* Analogous to read_memory_integer |
| except the length is understood to be 4. */ |
| long |
| read_register_stack_integer (memaddr, len) |
| CORE_ADDR memaddr; |
| int len; |
| { |
| char buf[4]; |
| read_register_stack (memaddr, buf, NULL, NULL); |
| return extract_signed_integer (buf, 4); |
| } |
| |
| /* Copy 4 bytes from GDB memory at MYADDR into inferior memory |
| at MEMADDR and put the actual address written into in |
| *ACTUAL_MEM_ADDR. */ |
| static void |
| write_register_stack (memaddr, myaddr, actual_mem_addr) |
| CORE_ADDR memaddr; |
| char *myaddr; |
| CORE_ADDR *actual_mem_addr; |
| { |
| long rfb = read_register (RFB_REGNUM); |
| long rsp = read_register (RSP_REGNUM); |
| /* If we don't do this 'info register' stops in the middle. */ |
| if (memaddr >= rstack_high_address) |
| { |
| /* It's in a register, but off the end of the stack. */ |
| if (actual_mem_addr != NULL) |
| *actual_mem_addr = 0; |
| } |
| else if (memaddr < rfb) |
| { |
| /* It's in a register. */ |
| int regnum = (memaddr - rsp) / 4 + LR0_REGNUM; |
| if (regnum < LR0_REGNUM || regnum > LR0_REGNUM + 127) |
| error ("Attempt to read register stack out of range."); |
| if (myaddr != NULL) |
| write_register (regnum, *(long *) myaddr); |
| if (actual_mem_addr != NULL) |
| *actual_mem_addr = 0; |
| } |
| else |
| { |
| /* It's in the memory portion of the register stack. */ |
| if (myaddr != NULL) |
| write_memory (memaddr, myaddr, 4); |
| if (actual_mem_addr != NULL) |
| *actual_mem_addr = memaddr; |
| } |
| } |
| |
| /* Find register number REGNUM relative to FRAME and put its |
| (raw) contents in *RAW_BUFFER. Set *OPTIMIZED if the variable |
| was optimized out (and thus can't be fetched). If the variable |
| was fetched from memory, set *ADDRP to where it was fetched from, |
| otherwise it was fetched from a register. |
| |
| The argument RAW_BUFFER must point to aligned memory. */ |
| |
| void |
| a29k_get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lvalp) |
| char *raw_buffer; |
| int *optimized; |
| CORE_ADDR *addrp; |
| struct frame_info *frame; |
| int regnum; |
| enum lval_type *lvalp; |
| { |
| struct frame_info *fi; |
| CORE_ADDR addr; |
| enum lval_type lval; |
| |
| if (!target_has_registers) |
| error ("No registers."); |
| |
| /* Probably now redundant with the target_has_registers check. */ |
| if (frame == 0) |
| return; |
| |
| /* Once something has a register number, it doesn't get optimized out. */ |
| if (optimized != NULL) |
| *optimized = 0; |
| if (regnum == RSP_REGNUM) |
| { |
| if (raw_buffer != NULL) |
| { |
| store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), frame->frame); |
| } |
| if (lvalp != NULL) |
| *lvalp = not_lval; |
| return; |
| } |
| else if (regnum == PC_REGNUM && frame->next != NULL) |
| { |
| if (raw_buffer != NULL) |
| { |
| store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), frame->pc); |
| } |
| |
| /* Not sure we have to do this. */ |
| if (lvalp != NULL) |
| *lvalp = not_lval; |
| |
| return; |
| } |
| else if (regnum == MSP_REGNUM) |
| { |
| if (raw_buffer != NULL) |
| { |
| if (frame->next != NULL) |
| { |
| store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), |
| frame->next->saved_msp); |
| } |
| else |
| read_register_gen (MSP_REGNUM, raw_buffer); |
| } |
| /* The value may have been computed, not fetched. */ |
| if (lvalp != NULL) |
| *lvalp = not_lval; |
| return; |
| } |
| else if (regnum < LR0_REGNUM || regnum >= LR0_REGNUM + 128) |
| { |
| /* These registers are not saved over procedure calls, |
| so just print out the current values. */ |
| if (raw_buffer != NULL) |
| read_register_gen (regnum, raw_buffer); |
| if (lvalp != NULL) |
| *lvalp = lval_register; |
| if (addrp != NULL) |
| *addrp = REGISTER_BYTE (regnum); |
| return; |
| } |
| |
| addr = frame->frame + (regnum - LR0_REGNUM) * 4; |
| if (raw_buffer != NULL) |
| read_register_stack (addr, raw_buffer, &addr, &lval); |
| if (lvalp != NULL) |
| *lvalp = lval; |
| if (addrp != NULL) |
| *addrp = addr; |
| } |
| |
| |
| /* Discard from the stack the innermost frame, |
| restoring all saved registers. */ |
| |
| void |
| pop_frame () |
| { |
| struct frame_info *frame = get_current_frame (); |
| CORE_ADDR rfb = read_register (RFB_REGNUM); |
| CORE_ADDR gr1 = frame->frame + frame->rsize; |
| CORE_ADDR lr1; |
| CORE_ADDR original_lr0; |
| int must_fix_lr0 = 0; |
| int i; |
| |
| /* If popping a dummy frame, need to restore registers. */ |
| if (PC_IN_CALL_DUMMY (read_register (PC_REGNUM), |
| read_register (SP_REGNUM), |
| FRAME_FP (frame))) |
| { |
| int lrnum = LR0_REGNUM + DUMMY_ARG / 4; |
| for (i = 0; i < DUMMY_SAVE_SR128; ++i) |
| write_register (SR_REGNUM (i + 128), read_register (lrnum++)); |
| for (i = 0; i < DUMMY_SAVE_SR160; ++i) |
| write_register (SR_REGNUM (i + 160), read_register (lrnum++)); |
| for (i = 0; i < DUMMY_SAVE_GREGS; ++i) |
| write_register (RETURN_REGNUM + i, read_register (lrnum++)); |
| /* Restore the PCs and prepare to restore LR0. */ |
| write_register (PC_REGNUM, read_register (lrnum++)); |
| write_register (NPC_REGNUM, read_register (lrnum++)); |
| write_register (PC2_REGNUM, read_register (lrnum++)); |
| original_lr0 = read_register (lrnum++); |
| must_fix_lr0 = 1; |
| } |
| |
| /* Restore the memory stack pointer. */ |
| write_register (MSP_REGNUM, frame->saved_msp); |
| /* Restore the register stack pointer. */ |
| write_register (GR1_REGNUM, gr1); |
| |
| /* If we popped a dummy frame, restore lr0 now that gr1 has been restored. */ |
| if (must_fix_lr0) |
| write_register (LR0_REGNUM, original_lr0); |
| |
| /* Check whether we need to fill registers. */ |
| lr1 = read_register (LR0_REGNUM + 1); |
| if (lr1 > rfb) |
| { |
| /* Fill. */ |
| int num_bytes = lr1 - rfb; |
| int i; |
| long word; |
| |
| write_register (RAB_REGNUM, read_register (RAB_REGNUM) + num_bytes); |
| write_register (RFB_REGNUM, lr1); |
| for (i = 0; i < num_bytes; i += 4) |
| { |
| /* Note: word is in host byte order. */ |
| word = read_memory_integer (rfb + i, 4); |
| write_register (LR0_REGNUM + ((rfb - gr1) % 0x80) + i / 4, word); |
| } |
| } |
| flush_cached_frames (); |
| } |
| |
| /* Push an empty stack frame, to record the current PC, etc. */ |
| |
| void |
| push_dummy_frame () |
| { |
| long w; |
| CORE_ADDR rab, gr1; |
| CORE_ADDR msp = read_register (MSP_REGNUM); |
| int lrnum, i; |
| CORE_ADDR original_lr0; |
| |
| /* Read original lr0 before changing gr1. This order isn't really needed |
| since GDB happens to have a snapshot of all the regs and doesn't toss |
| it when gr1 is changed. But it's The Right Thing To Do. */ |
| original_lr0 = read_register (LR0_REGNUM); |
| |
| /* Allocate the new frame. */ |
| gr1 = read_register (GR1_REGNUM) - DUMMY_FRAME_RSIZE; |
| write_register (GR1_REGNUM, gr1); |
| |
| #ifdef VXWORKS_TARGET |
| /* We force re-reading all registers to get the new local registers set |
| after gr1 has been modified. This fix is due to the lack of single |
| register read/write operation in the RPC interface between VxGDB and |
| VxWorks. This really must be changed ! */ |
| |
| vx_read_register (-1); |
| |
| #endif /* VXWORK_TARGET */ |
| |
| rab = read_register (RAB_REGNUM); |
| if (gr1 < rab) |
| { |
| /* We need to spill registers. */ |
| int num_bytes = rab - gr1; |
| CORE_ADDR rfb = read_register (RFB_REGNUM); |
| int i; |
| long word; |
| |
| write_register (RFB_REGNUM, rfb - num_bytes); |
| write_register (RAB_REGNUM, gr1); |
| for (i = 0; i < num_bytes; i += 4) |
| { |
| /* Note: word is in target byte order. */ |
| read_register_gen (LR0_REGNUM + i / 4, (char *) &word); |
| write_memory (rfb - num_bytes + i, (char *) &word, 4); |
| } |
| } |
| |
| /* There are no arguments in to the dummy frame, so we don't need |
| more than rsize plus the return address and lr1. */ |
| write_register (LR0_REGNUM + 1, gr1 + DUMMY_FRAME_RSIZE + 2 * 4); |
| |
| /* Set the memory frame pointer. */ |
| write_register (LR0_REGNUM + DUMMY_FRAME_RSIZE / 4 - 1, msp); |
| |
| /* Allocate arg_slop. */ |
| write_register (MSP_REGNUM, msp - 16 * 4); |
| |
| /* Save registers. */ |
| lrnum = LR0_REGNUM + DUMMY_ARG / 4; |
| for (i = 0; i < DUMMY_SAVE_SR128; ++i) |
| write_register (lrnum++, read_register (SR_REGNUM (i + 128))); |
| for (i = 0; i < DUMMY_SAVE_SR160; ++i) |
| write_register (lrnum++, read_register (SR_REGNUM (i + 160))); |
| for (i = 0; i < DUMMY_SAVE_GREGS; ++i) |
| write_register (lrnum++, read_register (RETURN_REGNUM + i)); |
| /* Save the PCs and LR0. */ |
| write_register (lrnum++, read_register (PC_REGNUM)); |
| write_register (lrnum++, read_register (NPC_REGNUM)); |
| write_register (lrnum++, read_register (PC2_REGNUM)); |
| |
| /* Why are we saving LR0? What would clobber it? (the dummy frame should |
| be below it on the register stack, no?). */ |
| write_register (lrnum++, original_lr0); |
| } |
| |
| |
| |
| /* |
| This routine takes three arguments and makes the cached frames look |
| as if these arguments defined a frame on the cache. This allows the |
| rest of `info frame' to extract the important arguments without much |
| difficulty. Since an individual frame on the 29K is determined by |
| three values (FP, PC, and MSP), we really need all three to do a |
| good job. */ |
| |
| struct frame_info * |
| setup_arbitrary_frame (argc, argv) |
| int argc; |
| CORE_ADDR *argv; |
| { |
| struct frame_info *frame; |
| |
| if (argc != 3) |
| error ("AMD 29k frame specifications require three arguments: rsp pc msp"); |
| |
| frame = create_new_frame (argv[0], argv[1]); |
| |
| if (!frame) |
| internal_error ("create_new_frame returned invalid frame id"); |
| |
| /* Creating a new frame munges the `frame' value from the current |
| GR1, so we restore it again here. FIXME, untangle all this |
| 29K frame stuff... */ |
| frame->frame = argv[0]; |
| |
| /* Our MSP is in argv[2]. It'd be intelligent if we could just |
| save this value in the FRAME. But the way it's set up (FIXME), |
| we must save our caller's MSP. We compute that by adding our |
| memory stack frame size to our MSP. */ |
| frame->saved_msp = argv[2] + frame->msize; |
| |
| return frame; |
| } |
| |
| int |
| gdb_print_insn_a29k (memaddr, info) |
| bfd_vma memaddr; |
| disassemble_info *info; |
| { |
| if (TARGET_BYTE_ORDER == BIG_ENDIAN) |
| return print_insn_big_a29k (memaddr, info); |
| else |
| return print_insn_little_a29k (memaddr, info); |
| } |
| |
| enum a29k_processor_types processor_type = a29k_unknown; |
| |
| void |
| a29k_get_processor_type () |
| { |
| unsigned int cfg_reg = (unsigned int) read_register (CFG_REGNUM); |
| |
| /* Most of these don't have freeze mode. */ |
| processor_type = a29k_no_freeze_mode; |
| |
| switch ((cfg_reg >> 28) & 0xf) |
| { |
| case 0: |
| fprintf_filtered (gdb_stderr, "Remote debugging an Am29000"); |
| break; |
| case 1: |
| fprintf_filtered (gdb_stderr, "Remote debugging an Am29005"); |
| break; |
| case 2: |
| fprintf_filtered (gdb_stderr, "Remote debugging an Am29050"); |
| processor_type = a29k_freeze_mode; |
| break; |
| case 3: |
| fprintf_filtered (gdb_stderr, "Remote debugging an Am29035"); |
| break; |
| case 4: |
| fprintf_filtered (gdb_stderr, "Remote debugging an Am29030"); |
| break; |
| case 5: |
| fprintf_filtered (gdb_stderr, "Remote debugging an Am2920*"); |
| break; |
| case 6: |
| fprintf_filtered (gdb_stderr, "Remote debugging an Am2924*"); |
| break; |
| case 7: |
| fprintf_filtered (gdb_stderr, "Remote debugging an Am29040"); |
| break; |
| default: |
| fprintf_filtered (gdb_stderr, "Remote debugging an unknown Am29k\n"); |
| /* Don't bother to print the revision. */ |
| return; |
| } |
| fprintf_filtered (gdb_stderr, " revision %c\n", 'A' + ((cfg_reg >> 24) & 0x0f)); |
| } |
| |
| #ifdef GET_LONGJMP_TARGET |
| /* Figure out where the longjmp will land. We expect that we have just entered |
| longjmp and haven't yet setup the stack frame, so the args are still in the |
| output regs. lr2 (LR2_REGNUM) points at the jmp_buf structure from which we |
| extract the pc (JB_PC) that we will land at. The pc is copied into ADDR. |
| This routine returns true on success */ |
| |
| int |
| get_longjmp_target (pc) |
| CORE_ADDR *pc; |
| { |
| CORE_ADDR jb_addr; |
| char buf[sizeof (CORE_ADDR)]; |
| |
| jb_addr = read_register (LR2_REGNUM); |
| |
| if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, (char *) buf, |
| sizeof (CORE_ADDR))) |
| return 0; |
| |
| *pc = extract_address ((PTR) buf, sizeof (CORE_ADDR)); |
| return 1; |
| } |
| #endif /* GET_LONGJMP_TARGET */ |
| |
| void |
| _initialize_a29k_tdep () |
| { |
| extern CORE_ADDR text_end; |
| |
| tm_print_insn = gdb_print_insn_a29k; |
| |
| /* FIXME, there should be a way to make a CORE_ADDR variable settable. */ |
| add_show_from_set |
| (add_set_cmd ("rstack_high_address", class_support, var_uinteger, |
| (char *) &rstack_high_address, |
| "Set top address in memory of the register stack.\n\ |
| Attempts to access registers saved above this address will be ignored\n\ |
| or will produce the value -1.", &setlist), |
| &showlist); |
| |
| /* FIXME, there should be a way to make a CORE_ADDR variable settable. */ |
| add_show_from_set |
| (add_set_cmd ("call_scratch_address", class_support, var_uinteger, |
| (char *) &text_end, |
| "Set address in memory where small amounts of RAM can be used\n\ |
| when making function calls into the inferior.", &setlist), |
| &showlist); |
| } |