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authorDaniel Jacobowitz <drow@false.org>2002-02-05 18:44:18 +0000
committerDaniel Jacobowitz <drow@false.org>2002-02-05 18:44:18 +0000
commitda6d8c049c8b6db7b83409c37e7bc12c67027ed8 (patch)
tree277b3a1dc11b5557d8f181baf46ced2edf2a382a /gdb/gdbserver/linux-low.c
parent44354ae183cc7d12c559514506b506cbed4d9d31 (diff)
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2002-02-05 Daniel Jacobowitz <drow@mvista.com>
* gdbserver/linux-low.c: New file, copied exactly from low-linux.c.
Diffstat (limited to 'gdb/gdbserver/linux-low.c')
-rw-r--r--gdb/gdbserver/linux-low.c777
1 files changed, 777 insertions, 0 deletions
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
new file mode 100644
index 0000000..726e276
--- /dev/null
+++ b/gdb/gdbserver/linux-low.c
@@ -0,0 +1,777 @@
+/* Low level interface to ptrace, for the remote server for GDB.
+ Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002
+ Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include "server.h"
+#include <sys/wait.h>
+#include "frame.h"
+#include "inferior.h"
+
+#include <stdio.h>
+#include <sys/param.h>
+#include <sys/dir.h>
+#include <sys/ptrace.h>
+#include <sys/user.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+
+/***************Begin MY defs*********************/
+static char my_registers[REGISTER_BYTES];
+char *registers = my_registers;
+/***************End MY defs*********************/
+
+#ifdef HAVE_SYS_REG_H
+#include <sys/reg.h>
+#endif
+
+/* Default the type of the ptrace transfer to int. */
+#ifndef PTRACE_XFER_TYPE
+#define PTRACE_XFER_TYPE int
+#endif
+
+extern int errno;
+
+static void initialize_arch (void);
+
+/* Start an inferior process and returns its pid.
+ ALLARGS is a vector of program-name and args. */
+
+int
+create_inferior (char *program, char **allargs)
+{
+ int pid;
+
+ pid = fork ();
+ if (pid < 0)
+ perror_with_name ("fork");
+
+ if (pid == 0)
+ {
+ ptrace (PTRACE_TRACEME, 0, 0, 0);
+
+ execv (program, allargs);
+
+ fprintf (stderr, "Cannot exec %s: %s.\n", program,
+ errno < sys_nerr ? sys_errlist[errno] : "unknown error");
+ fflush (stderr);
+ _exit (0177);
+ }
+
+ return pid;
+}
+
+/* Attach to an inferior process. */
+
+int
+myattach (int pid)
+{
+ if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0)
+ {
+ fprintf (stderr, "Cannot attach to process %d: %s (%d)\n", pid,
+ errno < sys_nerr ? sys_errlist[errno] : "unknown error",
+ errno);
+ fflush (stderr);
+ _exit (0177);
+ }
+
+ return 0;
+}
+
+/* Kill the inferior process. Make us have no inferior. */
+
+void
+kill_inferior (void)
+{
+ if (inferior_pid == 0)
+ return;
+ ptrace (PTRACE_KILL, inferior_pid, 0, 0);
+ wait (0);
+/*************inferior_died ();****VK**************/
+}
+
+/* Return nonzero if the given thread is still alive. */
+int
+mythread_alive (int pid)
+{
+ return 1;
+}
+
+/* Wait for process, returns status */
+
+unsigned char
+mywait (char *status)
+{
+ int pid;
+ union wait w;
+
+ enable_async_io ();
+ pid = waitpid (inferior_pid, &w, 0);
+ disable_async_io ();
+ if (pid != inferior_pid)
+ perror_with_name ("wait");
+
+ if (WIFEXITED (w))
+ {
+ fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w));
+ *status = 'W';
+ return ((unsigned char) WEXITSTATUS (w));
+ }
+ else if (!WIFSTOPPED (w))
+ {
+ fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w));
+ *status = 'X';
+ return ((unsigned char) WTERMSIG (w));
+ }
+
+ fetch_inferior_registers (0);
+
+ *status = 'T';
+ return ((unsigned char) WSTOPSIG (w));
+}
+
+/* Resume execution of the inferior process.
+ If STEP is nonzero, single-step it.
+ If SIGNAL is nonzero, give it that signal. */
+
+void
+myresume (int step, int signal)
+{
+ errno = 0;
+ ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal);
+ if (errno)
+ perror_with_name ("ptrace");
+}
+
+
+#if !defined (offsetof)
+#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER)
+#endif
+
+/* U_REGS_OFFSET is the offset of the registers within the u area. */
+#if !defined (U_REGS_OFFSET)
+#define U_REGS_OFFSET \
+ ptrace (PT_READ_U, inferior_pid, \
+ (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \
+ - KERNEL_U_ADDR
+#endif
+
+#ifdef I386_GNULINUX_TARGET
+/* This module only supports access to the general purpose registers.
+ Adjust the relevant constants accordingly.
+
+ FIXME: kettenis/2001-03-28: We should really use PTRACE_GETREGS to
+ get at the registers. Better yet, we should try to share code with
+ i386-linux-nat.c. */
+#undef NUM_FREGS
+#define NUM_FREGS 0
+#undef NUM_REGS
+#define NUM_REGS NUM_GREGS
+
+/* This stuff comes from i386-tdep.c. */
+
+/* i386_register_byte[i] is the offset into the register file of the
+ start of register number i. We initialize this from
+ i386_register_raw_size. */
+int i386_register_byte[MAX_NUM_REGS];
+
+/* i386_register_raw_size[i] is the number of bytes of storage in
+ GDB's register array occupied by register i. */
+int i386_register_raw_size[MAX_NUM_REGS] = {
+ 4, 4, 4, 4,
+ 4, 4, 4, 4,
+ 4, 4, 4, 4,
+ 4, 4, 4, 4,
+ 10, 10, 10, 10,
+ 10, 10, 10, 10,
+ 4, 4, 4, 4,
+ 4, 4, 4, 4,
+ 16, 16, 16, 16,
+ 16, 16, 16, 16,
+ 4
+};
+
+static void
+initialize_arch (void)
+{
+ /* Initialize the table saying where each register starts in the
+ register file. */
+ {
+ int i, offset;
+
+ offset = 0;
+ for (i = 0; i < MAX_NUM_REGS; i++)
+ {
+ i386_register_byte[i] = offset;
+ offset += i386_register_raw_size[i];
+ }
+ }
+}
+
+/* This stuff comes from i386-linux-nat.c. */
+
+/* Mapping between the general-purpose registers in `struct user'
+ format and GDB's register array layout. */
+static int regmap[] =
+{
+ EAX, ECX, EDX, EBX,
+ UESP, EBP, ESI, EDI,
+ EIP, EFL, CS, SS,
+ DS, ES, FS, GS
+};
+
+/* Return the address of register REGNUM. BLOCKEND is the value of
+ u.u_ar0, which should point to the registers. */
+
+CORE_ADDR
+register_u_addr (CORE_ADDR blockend, int regnum)
+{
+ return (blockend + 4 * regmap[regnum]);
+}
+#elif defined(TARGET_M68K)
+static void
+initialize_arch (void)
+{
+ return;
+}
+
+/* This table must line up with REGISTER_NAMES in tm-m68k.h */
+static int regmap[] =
+{
+#ifdef PT_D0
+ PT_D0, PT_D1, PT_D2, PT_D3, PT_D4, PT_D5, PT_D6, PT_D7,
+ PT_A0, PT_A1, PT_A2, PT_A3, PT_A4, PT_A5, PT_A6, PT_USP,
+ PT_SR, PT_PC,
+#else
+ 14, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15,
+ 17, 18,
+#endif
+#ifdef PT_FP0
+ PT_FP0, PT_FP1, PT_FP2, PT_FP3, PT_FP4, PT_FP5, PT_FP6, PT_FP7,
+ PT_FPCR, PT_FPSR, PT_FPIAR
+#else
+ 21, 24, 27, 30, 33, 36, 39, 42, 45, 46, 47
+#endif
+};
+
+/* BLOCKEND is the value of u.u_ar0, and points to the place where GS
+ is stored. */
+
+int
+m68k_linux_register_u_addr (int blockend, int regnum)
+{
+ return (blockend + 4 * regmap[regnum]);
+}
+#elif defined(IA64_GNULINUX_TARGET)
+#undef NUM_FREGS
+#define NUM_FREGS 0
+
+#include <asm/ptrace_offsets.h>
+
+static int u_offsets[] =
+ {
+ /* general registers */
+ -1, /* gr0 not available; i.e, it's always zero */
+ PT_R1,
+ PT_R2,
+ PT_R3,
+ PT_R4,
+ PT_R5,
+ PT_R6,
+ PT_R7,
+ PT_R8,
+ PT_R9,
+ PT_R10,
+ PT_R11,
+ PT_R12,
+ PT_R13,
+ PT_R14,
+ PT_R15,
+ PT_R16,
+ PT_R17,
+ PT_R18,
+ PT_R19,
+ PT_R20,
+ PT_R21,
+ PT_R22,
+ PT_R23,
+ PT_R24,
+ PT_R25,
+ PT_R26,
+ PT_R27,
+ PT_R28,
+ PT_R29,
+ PT_R30,
+ PT_R31,
+ /* gr32 through gr127 not directly available via the ptrace interface */
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ /* Floating point registers */
+ -1, -1, /* f0 and f1 not available (f0 is +0.0 and f1 is +1.0) */
+ PT_F2,
+ PT_F3,
+ PT_F4,
+ PT_F5,
+ PT_F6,
+ PT_F7,
+ PT_F8,
+ PT_F9,
+ PT_F10,
+ PT_F11,
+ PT_F12,
+ PT_F13,
+ PT_F14,
+ PT_F15,
+ PT_F16,
+ PT_F17,
+ PT_F18,
+ PT_F19,
+ PT_F20,
+ PT_F21,
+ PT_F22,
+ PT_F23,
+ PT_F24,
+ PT_F25,
+ PT_F26,
+ PT_F27,
+ PT_F28,
+ PT_F29,
+ PT_F30,
+ PT_F31,
+ PT_F32,
+ PT_F33,
+ PT_F34,
+ PT_F35,
+ PT_F36,
+ PT_F37,
+ PT_F38,
+ PT_F39,
+ PT_F40,
+ PT_F41,
+ PT_F42,
+ PT_F43,
+ PT_F44,
+ PT_F45,
+ PT_F46,
+ PT_F47,
+ PT_F48,
+ PT_F49,
+ PT_F50,
+ PT_F51,
+ PT_F52,
+ PT_F53,
+ PT_F54,
+ PT_F55,
+ PT_F56,
+ PT_F57,
+ PT_F58,
+ PT_F59,
+ PT_F60,
+ PT_F61,
+ PT_F62,
+ PT_F63,
+ PT_F64,
+ PT_F65,
+ PT_F66,
+ PT_F67,
+ PT_F68,
+ PT_F69,
+ PT_F70,
+ PT_F71,
+ PT_F72,
+ PT_F73,
+ PT_F74,
+ PT_F75,
+ PT_F76,
+ PT_F77,
+ PT_F78,
+ PT_F79,
+ PT_F80,
+ PT_F81,
+ PT_F82,
+ PT_F83,
+ PT_F84,
+ PT_F85,
+ PT_F86,
+ PT_F87,
+ PT_F88,
+ PT_F89,
+ PT_F90,
+ PT_F91,
+ PT_F92,
+ PT_F93,
+ PT_F94,
+ PT_F95,
+ PT_F96,
+ PT_F97,
+ PT_F98,
+ PT_F99,
+ PT_F100,
+ PT_F101,
+ PT_F102,
+ PT_F103,
+ PT_F104,
+ PT_F105,
+ PT_F106,
+ PT_F107,
+ PT_F108,
+ PT_F109,
+ PT_F110,
+ PT_F111,
+ PT_F112,
+ PT_F113,
+ PT_F114,
+ PT_F115,
+ PT_F116,
+ PT_F117,
+ PT_F118,
+ PT_F119,
+ PT_F120,
+ PT_F121,
+ PT_F122,
+ PT_F123,
+ PT_F124,
+ PT_F125,
+ PT_F126,
+ PT_F127,
+ /* predicate registers - we don't fetch these individually */
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ /* branch registers */
+ PT_B0,
+ PT_B1,
+ PT_B2,
+ PT_B3,
+ PT_B4,
+ PT_B5,
+ PT_B6,
+ PT_B7,
+ /* virtual frame pointer and virtual return address pointer */
+ -1, -1,
+ /* other registers */
+ PT_PR,
+ PT_CR_IIP, /* ip */
+ PT_CR_IPSR, /* psr */
+ PT_CFM, /* cfm */
+ /* kernel registers not visible via ptrace interface (?) */
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ /* hole */
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ PT_AR_RSC,
+ PT_AR_BSP,
+ PT_AR_BSPSTORE,
+ PT_AR_RNAT,
+ -1,
+ -1, /* Not available: FCR, IA32 floating control register */
+ -1, -1,
+ -1, /* Not available: EFLAG */
+ -1, /* Not available: CSD */
+ -1, /* Not available: SSD */
+ -1, /* Not available: CFLG */
+ -1, /* Not available: FSR */
+ -1, /* Not available: FIR */
+ -1, /* Not available: FDR */
+ -1,
+ PT_AR_CCV,
+ -1, -1, -1,
+ PT_AR_UNAT,
+ -1, -1, -1,
+ PT_AR_FPSR,
+ -1, -1, -1,
+ -1, /* Not available: ITC */
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ PT_AR_PFS,
+ PT_AR_LC,
+ -1, /* Not available: EC, the Epilog Count register */
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1,
+ /* nat bits - not fetched directly; instead we obtain these bits from
+ either rnat or unat or from memory. */
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1,
+ };
+
+int
+ia64_register_u_addr (int blockend, int regnum)
+{
+ int addr;
+
+ if (regnum < 0 || regnum >= NUM_REGS)
+ error ("Invalid register number %d.", regnum);
+
+ addr = u_offsets[regnum];
+ if (addr == -1)
+ addr = 0;
+
+ return addr;
+}
+
+static void
+initialize_arch (void)
+{
+ return;
+}
+
+#elif defined(ARM_GNULINUX_TARGET)
+int arm_register_u_addr(blockend, regnum)
+ int blockend;
+ int regnum;
+{
+ return blockend + REGISTER_BYTE(regnum);
+}
+
+static void
+initialize_arch ()
+{
+}
+#endif
+
+CORE_ADDR
+register_addr (int regno, CORE_ADDR blockend)
+{
+ CORE_ADDR addr;
+
+ if (regno < 0 || regno >= NUM_REGS)
+ error ("Invalid register number %d.", regno);
+
+ REGISTER_U_ADDR (addr, blockend, regno);
+
+ return addr;
+}
+
+/* Fetch one register. */
+
+static void
+fetch_register (int regno)
+{
+ CORE_ADDR regaddr;
+ register int i;
+
+ /* Offset of registers within the u area. */
+ unsigned int offset;
+
+ offset = U_REGS_OFFSET;
+
+ regaddr = register_addr (regno, offset);
+ for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE))
+ {
+ errno = 0;
+ *(PTRACE_XFER_TYPE *) &registers[REGISTER_BYTE (regno) + i] =
+ ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0);
+ regaddr += sizeof (PTRACE_XFER_TYPE);
+ if (errno != 0)
+ {
+ /* Warning, not error, in case we are attached; sometimes the
+ kernel doesn't let us at the registers. */
+ char *err = strerror (errno);
+ char *msg = alloca (strlen (err) + 128);
+ sprintf (msg, "reading register %d: %s", regno, err);
+ error (msg);
+ goto error_exit;
+ }
+ }
+error_exit:;
+}
+
+/* Fetch all registers, or just one, from the child process. */
+
+void
+fetch_inferior_registers (int regno)
+{
+ if (regno == -1 || regno == 0)
+ for (regno = 0; regno < NUM_REGS - NUM_FREGS; regno++)
+ fetch_register (regno);
+ else
+ fetch_register (regno);
+}
+
+/* Store our register values back into the inferior.
+ If REGNO is -1, do this for all registers.
+ Otherwise, REGNO specifies which register (so we can save time). */
+
+void
+store_inferior_registers (int regno)
+{
+ CORE_ADDR regaddr;
+ int i;
+ unsigned int offset = U_REGS_OFFSET;
+
+ if (regno >= 0)
+ {
+#if 0
+ if (CANNOT_STORE_REGISTER (regno))
+ return;
+#endif
+ regaddr = register_addr (regno, offset);
+ errno = 0;
+#if 0
+ if (regno == PCOQ_HEAD_REGNUM || regno == PCOQ_TAIL_REGNUM)
+ {
+ scratch = *(int *) &registers[REGISTER_BYTE (regno)] | 0x3;
+ ptrace (PT_WUREGS, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
+ scratch, 0);
+ if (errno != 0)
+ {
+ /* Error, even if attached. Failing to write these two
+ registers is pretty serious. */
+ sprintf (buf, "writing register number %d", regno);
+ perror_with_name (buf);
+ }
+ }
+ else
+#endif
+ for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
+ {
+ errno = 0;
+ ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
+ *(int *) &registers[REGISTER_BYTE (regno) + i]);
+ if (errno != 0)
+ {
+ /* Warning, not error, in case we are attached; sometimes the
+ kernel doesn't let us at the registers. */
+ char *err = strerror (errno);
+ char *msg = alloca (strlen (err) + 128);
+ sprintf (msg, "writing register %d: %s",
+ regno, err);
+ error (msg);
+ return;
+ }
+ regaddr += sizeof (int);
+ }
+ }
+ else
+ for (regno = 0; regno < NUM_REGS - NUM_FREGS; regno++)
+ store_inferior_registers (regno);
+}
+
+/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory
+ in the NEW_SUN_PTRACE case.
+ It ought to be straightforward. But it appears that writing did
+ not write the data that I specified. I cannot understand where
+ it got the data that it actually did write. */
+
+/* Copy LEN bytes from inferior's memory starting at MEMADDR
+ to debugger memory starting at MYADDR. */
+
+void
+read_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
+{
+ register int i;
+ /* Round starting address down to longword boundary. */
+ register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
+ /* Round ending address up; get number of longwords that makes. */
+ register int count
+ = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1)
+ / sizeof (PTRACE_XFER_TYPE);
+ /* Allocate buffer of that many longwords. */
+ register PTRACE_XFER_TYPE *buffer
+ = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+
+ /* Read all the longwords */
+ for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+ {
+ buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, addr, 0);
+ }
+
+ /* Copy appropriate bytes out of the buffer. */
+ memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len);
+}
+
+/* Copy LEN bytes of data from debugger memory at MYADDR
+ to inferior's memory at MEMADDR.
+ On failure (cannot write the inferior)
+ returns the value of errno. */
+
+int
+write_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len)
+{
+ register int i;
+ /* Round starting address down to longword boundary. */
+ register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE);
+ /* Round ending address up; get number of longwords that makes. */
+ register int count
+ = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE);
+ /* Allocate buffer of that many longwords. */
+ register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE));
+ extern int errno;
+
+ /* Fill start and end extra bytes of buffer with existing memory data. */
+
+ buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, addr, 0);
+
+ if (count > 1)
+ {
+ buffer[count - 1]
+ = ptrace (PTRACE_PEEKTEXT, inferior_pid,
+ addr + (count - 1) * sizeof (PTRACE_XFER_TYPE), 0);
+ }
+
+ /* Copy data to be written over corresponding part of buffer */
+
+ memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
+
+ /* Write the entire buffer. */
+
+ for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
+ {
+ errno = 0;
+ ptrace (PTRACE_POKETEXT, inferior_pid, addr, buffer[i]);
+ if (errno)
+ return errno;
+ }
+
+ return 0;
+}
+
+void
+initialize_low (void)
+{
+ initialize_arch ();
+}