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Diffstat (limited to 'gdb/i386-xdep.c')
| -rw-r--r-- | gdb/i386-xdep.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/gdb/i386-xdep.c b/gdb/i386-xdep.c new file mode 100644 index 0000000..dddf22d --- /dev/null +++ b/gdb/i386-xdep.c @@ -0,0 +1,357 @@ +/* Intel 386 stuff. + Copyright (C) 1988, 1989 Free Software Foundation, Inc. + +This file is part of GDB. + +GDB 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 1, or (at your option) +any later version. + +GDB 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 GDB; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include <stdio.h> +#include "defs.h" +#include "param.h" +#include "frame.h" +#include "inferior.h" +#include "gdbcore.h" + +#ifdef USG +#include <sys/types.h> +#endif + +#include <sys/param.h> +#include <sys/dir.h> +#include <signal.h> +#include <sys/user.h> +#include <sys/ioctl.h> +#include <fcntl.h> + +#include <sys/file.h> +#include <sys/stat.h> + +#include <sys/reg.h> + +/* this table must line up with REGISTER_NAMES in m-i386.h */ +/* symbols like 'EAX' come from <sys/reg.h> */ +static int regmap[] = +{ + EAX, ECX, EDX, EBX, + UESP, EBP, ESI, EDI, + EIP, EFL, CS, SS, + DS, ES, FS, GS, +}; + +/* blockend is the value of u.u_ar0, and points to the + * place where GS is stored + */ +i386_register_u_addr (blockend, regnum) +{ +#if 0 + /* this will be needed if fp registers are reinstated */ + /* for now, you can look at them with 'info float' + * sys5 wont let you change them with ptrace anyway + */ + if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM) + { + int ubase, fpstate; + struct user u; + ubase = blockend + 4 * (SS + 1) - KSTKSZ; + fpstate = ubase + ((char *)&u.u_fpstate - (char *)&u); + return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM)); + } + else +#endif + return (blockend + 4 * regmap[regnum]); + +} + +/* This is broken for cross debugging. Possible solutions are: + +1. Don't worry about whether the thing compiles for cross-debugging. +Go ahead and call them from i386-tdep.c. +1a. Same thing but use some macros in xm-i386.h so that gdb will +compile for cross-debugging but just give an error (or some such behavior) +when you attempt to convert floats. + +2. Write a portable (in the sense of running on any machine; it would +always be for i387 floating-point formats) extended<->double converter +(which just deals with the values as arrays of char). + +3. Assume the host machine has *some* IEEE chip. However, IEEE does +not standardize formats for extended floats (387 is 10 bytes, 68881 is +12 bytes), so this won't work. */ + +i387_to_double (from, to) + char *from; + char *to; +{ + long *lp; + /* push extended mode on 387 stack, then pop in double mode + * + * first, set exception masks so no error is generated - + * number will be rounded to inf or 0, if necessary + */ + asm ("pushl %eax"); /* grab a stack slot */ + asm ("fstcw (%esp)"); /* get 387 control word */ + asm ("movl (%esp),%eax"); /* save old value */ + asm ("orl $0x3f,%eax"); /* mask all exceptions */ + asm ("pushl %eax"); + asm ("fldcw (%esp)"); /* load new value into 387 */ + + asm ("movl 8(%ebp),%eax"); + asm ("fldt (%eax)"); /* push extended number on 387 stack */ + asm ("fwait"); + asm ("movl 12(%ebp),%eax"); + asm ("fstpl (%eax)"); /* pop double */ + asm ("fwait"); + + asm ("popl %eax"); /* flush modified control word */ + asm ("fnclex"); /* clear exceptions */ + asm ("fldcw (%esp)"); /* restore original control word */ + asm ("popl %eax"); /* flush saved copy */ +} + +double_to_i387 (from, to) + char *from; + char *to; +{ + /* push double mode on 387 stack, then pop in extended mode + * no errors are possible because every 64-bit pattern + * can be converted to an extended + */ + asm ("movl 8(%ebp),%eax"); + asm ("fldl (%eax)"); + asm ("fwait"); + asm ("movl 12(%ebp),%eax"); + asm ("fstpt (%eax)"); + asm ("fwait"); +} + +struct env387 +{ + unsigned short control; + unsigned short r0; + unsigned short status; + unsigned short r1; + unsigned short tag; + unsigned short r2; + unsigned long eip; + unsigned short code_seg; + unsigned short opcode; + unsigned long operand; + unsigned short operand_seg; + unsigned short r3; + unsigned char regs[8][10]; +}; + +static +print_387_control_word (control) +unsigned short control; +{ + printf ("control 0x%04x: ", control); + printf ("compute to "); + switch ((control >> 8) & 3) + { + case 0: printf ("24 bits; "); break; + case 1: printf ("(bad); "); break; + case 2: printf ("53 bits; "); break; + case 3: printf ("64 bits; "); break; + } + printf ("round "); + switch ((control >> 10) & 3) + { + case 0: printf ("NEAREST; "); break; + case 1: printf ("DOWN; "); break; + case 2: printf ("UP; "); break; + case 3: printf ("CHOP; "); break; + } + if (control & 0x3f) + { + printf ("mask:"); + if (control & 0x0001) printf (" INVALID"); + if (control & 0x0002) printf (" DENORM"); + if (control & 0x0004) printf (" DIVZ"); + if (control & 0x0008) printf (" OVERF"); + if (control & 0x0010) printf (" UNDERF"); + if (control & 0x0020) printf (" LOS"); + printf (";"); + } + printf ("\n"); + if (control & 0xe080) printf ("warning: reserved bits on 0x%x\n", + control & 0xe080); +} + +static +print_387_status_word (status) + unsigned short status; +{ + printf ("status 0x%04x: ", status); + if (status & 0xff) + { + printf ("exceptions:"); + if (status & 0x0001) printf (" INVALID"); + if (status & 0x0002) printf (" DENORM"); + if (status & 0x0004) printf (" DIVZ"); + if (status & 0x0008) printf (" OVERF"); + if (status & 0x0010) printf (" UNDERF"); + if (status & 0x0020) printf (" LOS"); + if (status & 0x0040) printf (" FPSTACK"); + printf ("; "); + } + printf ("flags: %d%d%d%d; ", + (status & 0x4000) != 0, + (status & 0x0400) != 0, + (status & 0x0200) != 0, + (status & 0x0100) != 0); + + printf ("top %d\n", (status >> 11) & 7); +} + +static +print_387_status (status, ep) + unsigned short status; + struct env387 *ep; +{ + int i; + int bothstatus; + int top; + int fpreg; + unsigned char *p; + + bothstatus = ((status != 0) && (ep->status != 0)); + if (status != 0) + { + if (bothstatus) + printf ("u: "); + print_387_status_word (status); + } + + if (ep->status != 0) + { + if (bothstatus) + printf ("e: "); + print_387_status_word (ep->status); + } + + print_387_control_word (ep->control); + printf ("last exception: "); + printf ("opcode 0x%x; ", ep->opcode); + printf ("pc 0x%x:0x%x; ", ep->code_seg, ep->eip); + printf ("operand 0x%x:0x%x\n", ep->operand_seg, ep->operand); + + top = (ep->status >> 11) & 7; + + printf ("regno tag msb lsb value\n"); + for (fpreg = 7; fpreg >= 0; fpreg--) + { + double val; + + printf ("%s %d: ", fpreg == top ? "=>" : " ", fpreg); + + switch ((ep->tag >> (fpreg * 2)) & 3) + { + case 0: printf ("valid "); break; + case 1: printf ("zero "); break; + case 2: printf ("trap "); break; + case 3: printf ("empty "); break; + } + for (i = 9; i >= 0; i--) + printf ("%02x", ep->regs[fpreg][i]); + + i387_to_double (ep->regs[fpreg], (char *)&val); + printf (" %g\n", val); + } + if (ep->r0) + printf ("warning: reserved0 is 0x%x\n", ep->r0); + if (ep->r1) + printf ("warning: reserved1 is 0x%x\n", ep->r1); + if (ep->r2) + printf ("warning: reserved2 is 0x%x\n", ep->r2); + if (ep->r3) + printf ("warning: reserved3 is 0x%x\n", ep->r3); +} + +#ifndef U_FPSTATE +#define U_FPSTATE(u) u.u_fpstate +#endif + +i386_float_info () +{ + struct user u; /* just for address computations */ + int i; + /* fpstate defined in <sys/user.h> */ + struct fpstate *fpstatep; + char buf[sizeof (struct fpstate) + 2 * sizeof (int)]; + unsigned int uaddr; + char fpvalid; + unsigned int rounded_addr; + unsigned int rounded_size; + extern int corechan; + int skip; + + uaddr = (char *)&u.u_fpvalid - (char *)&u; + if (have_inferior_p()) + { + unsigned int data; + unsigned int mask; + + rounded_addr = uaddr & -sizeof (int); + data = ptrace (3, inferior_pid, rounded_addr, 0); + mask = 0xff << ((uaddr - rounded_addr) * 8); + + fpvalid = ((data & mask) != 0); + } + else + { + if (lseek (corechan, uaddr, 0) < 0) + perror ("seek on core file"); + if (myread (corechan, &fpvalid, 1) < 0) + perror ("read on core file"); + + } + + if (fpvalid == 0) + { + printf ("no floating point status saved\n"); + return; + } + + uaddr = (char *)&U_FPSTATE(u) - (char *)&u; + if (have_inferior_p ()) + { + int *ip; + + rounded_addr = uaddr & -sizeof (int); + rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) + + sizeof (int) - 1) / sizeof (int); + skip = uaddr - rounded_addr; + + ip = (int *)buf; + for (i = 0; i < rounded_size; i++) + { + *ip++ = ptrace (3, inferior_pid, rounded_addr, 0); + rounded_addr += sizeof (int); + } + } + else + { + if (lseek (corechan, uaddr, 0) < 0) + perror_with_name ("seek on core file"); + if (myread (corechan, buf, sizeof (struct fpstate)) < 0) + perror_with_name ("read from core file"); + skip = 0; + } + + fpstatep = (struct fpstate *)(buf + skip); + print_387_status (fpstatep->status, (struct env387 *)fpstatep->state); +} + |